1.
Crespo, Leonardo
(författare)
Resistance to aphids in wheat : from a plant breeding perspective
2012
Rapport (övrigt vetenskapligt/konstnärligt) abstract
Wheat is one of the main staple foods in the world. Among the many constraints there are for wheat production, aphids cause severe damage by their feeding, and by virus transmission. The current document summarizes the available information regarding wheat resistance to aphids. The text is divided into four sections. The first section “Plant resistance to insects: from a historical perspective” serves as an introduction, where some important factors shaping Plant Resistance to insects as a discipline are presented. The section “Categories of resistance and plant defenses to aphids”, presents the concepts of Plant Resistance to insects, with wheat-aphid examples. The methods to assess the categories of resistance are briefly discussed in this section as well. “Genetic resources for resistance to aphids in wheat”, the third part of the document, is focused on the wheat relatives in which resistance to biotic stresses and to aphids in particular can be found. The aim of this section is to describe the resistance donors in relation to each of the main aphid species that attack wheat. Finally, some aspects on how to improve wheat for resistance to aphids are discussed in the fourth section, “Considerations for wheat breeding”.
2.
Crespo, Leonardo, et al.
(författare)
Resistance to multiple cereal aphids in wheat-alien substitution and translocation lines
2013
Ingår i: Arthropod-Plant Interactions. - : Springer Science and Business Media LLC. - 1872-8855 .- 1872-8847. ; 7, s. 535-545
Tidskriftsartikel (refereegranskat) abstract
Rhopalosiphum padi, Schizaphis graminum, and Sitobion avenae are three of the most destructive aphid species of wheat (Triticum aestivum L.). They can significantly reduce wheat yields directly by feeding and indirectly by transmitting viruses. This study aimed to search for resistance to these aphid species among lines derived from different rye (Secale cereale) origins and from Aegilops speltoides, all in the genetic background of the wheat cultivar Pavon F76. Resistance was quantified as aphid weight (R. padi, S. avenae, and S. graminum) and the number of aphids and percentage of infested leaf area exhibiting chlorosis (S. graminum). The most resistant genotypes reduced R. padi and S. avenae weight by 24.2 and 34.3 %, respectively, at the seedling stage, compared with Pavon F76 control plants. Strong S. graminum resistance was found only in A. speltoides-derived lines, the most resistant of which (7A.7S-L5) sustained just 3 % chlorosis and reduced S. graminum colony weight by 67.7 %. One line carrying the 1AL.1RS(am) wheat-rye translocation from Amigo wheat (originally from Insave rye) reduced S. avenae weight by 23.2 and 21.8 % in seedling and adult plants, respectively. Single genotypes carrying the complete 1R chromosome or the 1RS chromosome arm derived from E12165 wheat and Presto triticale proved to be resistant to both R. padi and S. avenae at the seedling stage. Further research should be conducted to unravel the genetic basis of resistance to these aphids in 1RS genotypes. The sources of resistance identified here may be useful for incorporating multiple aphid species resistance in wheat breeding programs, particularly for R. padi and S. avenae, to which no resistant wheats have been bred.
3.
Dida, Mulatu Geleta, et al.
(författare)
Domestication of Lepidium campestre as part of Mistra Biotech, a research programme focused on agro biotechnology for sustainable food
2014
Ingår i: Perennial Crops for Food Security Proceedings of the FAO Expert Workshop. - 9789251079980 - 9789251079997 ; , s. 141-147
Bokkapitel (refereegranskat) abstract
Several important challenges are facing agriculture . In the stride towards lowering the negative environmental impact of food production while maint aining and increasing the production, both basic farming practices and novel technologies are important tools. The use of biotechnology in breeding, however, is not uncontroversial. The crit icism has many angles and often relates to the applications brought forward by large, multinationa l companies, and farmers growing dependence on these companies when it comes to seeds. Question s are being raised about ethical acceptability, and about the health and environmental impacts. A g eneral aversion to what is often referred to as the “industrialization” of agriculture, and t o “unnaturalness”, also emerges in the debate. In the research programme referred to as Mistra Biotech , we include both philosophy and natural and social sciences. The overall goal is to facilitate production systems that are sustainable from ecological, social and economic perspectives. The objectives of the programme include developing: * new elite plant lines that have benefits for consumers, farmers, the food industry and the environment; * agribiotechnology tools that are important for achieving new product qualities, healthier crops and livestock, and for solving environmental problems in agriculture; * basis for sustainable production systems that contribute to increased competitiveness in Swedish agriculture and food production; * tools for ethical scrutiny of agricultural biotechnology that combine high demands on safety with encouragement of innovations; * basis for improved regulatory approaches and private-public relationships. The programme includes six component projects, in which domestication of a new biennial oilseed crop Lepidium campestre (field cress) is a major research focus. Questions we will try to answer within this programme include: Can biotechnology be used to improve crops which mitigate climate change or benefit the environment? What potential is there to commercialize such a crop? How would the consumers react to products made from it? Can breeding technology be improved further? Why does the market for genetically improved plant and animal materials look the way it does? What ethical concerns does the use of biotechnology raise? And how do all these issues feed into future agricultural systems? The results are integrated in the synthesis project called the Centre for Agriculture and Food Systems Analysis and Synthesis (AgriSA). Here we emphasise the research within Component Project1, with a focus on the domestication of field cress.
4.
Nybom, Hilde
(författare)
Fyra nya äpplesorter från Balsgård
2014
Ingår i: LTV-fakultetens faktablad.
Annan publikation (populärvet., debatt m.m.) abstract
Fakulteten för landskapsarkitektur, trädgårds- och växtproduktionsvetenskap 2014 För SLU är frukt och bärförädling en viktig verksamhet som bedrivs på Balsgård, 10 km norr om Kristianstad i nordöstra Skåne (Nybom 2006, 2010). Innan SLU kom in i bilden 1970, hade äppleförädling bedrivits på Balsgård genom Föreningen för växtförädling av frukt och bär sedan 40-talet. Balsgård är beläget i ett av landets äldsta frukt- odlingsdistrikt, vilket lämpar sig utmärkt för äppleträd. Här finns lätta och varma jordar samt gynnsamma odlingslägen på sluttningar ner mot sjöarna som ligger tätt i det mjukt böljande landskapet. Den första äpplesorten från Balsgård blev Alice, som lanserades i slutet av 60-talet (Nybom 2012c). Denna följdes snart av storsäljare som Aroma och Katja, samt den synnerligen vinterhärdiga Rödluvan. På senare tid är det främst de välsmakande och sjukdomsresistenta syskonsorterna Frida och Fredrik som låtit tala om sig
5.
6.
Alexandersson, Erik, et al.
(författare)
Tro får inte ersätta vetenskap
2014
Ingår i: Svenska dagbladet. - 1101-2412.
Tidskriftsartikel (populärvet., debatt m.m.)
7.
Andersson, Mariette
(författare)
Comparative Transcriptome Analysis of Three Oil Palm Fruit and Seed Tissues That Differ in Oil Content and Fatty Acid Composition
2013
Ingår i: Plant Physiology. - : Oxford University Press (OUP). - 0032-0889 .- 1532-2548. ; 162, s. 1337-1358
Tidskriftsartikel (refereegranskat) abstract
Oil palm (Elaeis guineensis) produces two oils of major economic importance, commonly referred to as palm oil and palm kernel oil, extracted from the mesocarp and the endosperm, respectively. While lauric acid predominates in endosperm oil, the major fatty acids (FAs) of mesocarp oil are palmitic and oleic acids. The oil palm embryo also stores oil, which contains a significant proportion of linoleic acid. In addition, the three tissues display high variation for oil content at maturity. To gain insight into the mechanisms that govern such differences in oil content and FA composition, tissue transcriptome and lipid composition were compared during development. The contribution of the cytosolic and plastidial glycolytic routes differed markedly between the mesocarp and seed tissues, but transcriptional patterns of genes involved in the conversion of sucrose to pyruvate were not related to variations for oil content. Accumulation of lauric acid relied on the dramatic up-regulation of a specialized acyl-acyl carrier protein thioesterase paralog and the concerted recruitment of specific isoforms of triacylglycerol assembly enzymes. Three paralogs of the WRINKLED1 (WRI1) transcription factor were identified, of which EgWRI1-1 and EgWRI1-2 were massively transcribed during oil deposition in the mesocarp and the endosperm, respectively. None of the three WRI1 paralogs were detected in the embryo. The transcription level of FA synthesis genes correlated with the amount of WRI1 transcripts and oil content. Changes in triacylglycerol content and FA composition of Nicotiana benthamiana leaves infiltrated with various combinations of WRI1 and FatB paralogs from oil palm validated functions inferred from transcriptome analysis.
8.
Arif, Usman
(författare)
Effect of wounding and light exposure on sterol, glycoalkaloid, and calystegine levels in potato plants (Solanum tuberosum L. group Tuberosum)
2013
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Steroidal glycoalkaloids (SGA) are neurotoxic substances that are present in some members of the Solanaceae family, including crop species like potato (Solanum tuberosum L.) and tomato. The SGA level in the potato tuber is a genetic trait, but certain environmental factors such as wounding and light exposure can increase SGA levels several-fold, which may render tubers unsuitable for human consumption. There is little information about SGA biosynthesis. The sterol cholesterol is commonly regarded as a SGA precursor, but there is little evidence for this view. To increase our understanding of the SGA biosynthesis and its molecular regulation, a microarray screen was performed using tubers from two potato cultivars subjected to wound and light treatments. Along with an alteration of sterol and SGA levels, the treatments were associated with an up-regulation of a small set of genes in sterol and SGA metabolism, including a gene encoding for the sterol reductase DWF1. DWF1 genes were found in two differentially regulated subtypes; DWF1 and DWF1-like (DWF1-L). Alteration of DWF1 and DWF1-L expression in transgenic potato showed a role for these genes in sterol and SGA synthesis. Also up-regulated in the microarray study were three transaminase-like genes, and role of StTAM1 in SGA synthesis was investigated by overexpression in transgenic potato. This resulted in elevated SGA levels, indicating the presence of a transamination in SGA synthesis. The genetic variation and stress responsiveness in Swedish potato cultivars regarding SGA and calystegine alkaloids (CA) level was determined by subjecting tubers to wounding, light exposure and elevated temperature. Only light and wounding increased SGA levels, and variation in the response was observed among the cultivars. CA levels were not stress-regulated, indicating that SGA and CA synthesis are not interrelated. These results show that the SGA level in potato tubers are regulated by a concerted action of a small set of key genes acting at different steps in the sterol and SGA pathways. Results also demonstrate a genetic variation in stress responsiveness among Swedish potato cultivars, and have identified the most sensitive ones. Results could in the near future be used to improve post-harvest handling of potato cultivars.
9.
10.
Desta, Zeratsion Abera, et al.
(författare)
Genomic selection: genome-wide prediction in plant improvement
2014
Ingår i: Trends in Plant Science. - : Elsevier BV. - 1360-1385 .- 1878-4372. ; 19, s. 592–601-
Forskningsöversikt (refereegranskat) abstract
Association analysis is used to measure relations between markers and quantitative trait loci (QTL). Their estimation ignores genes with small effects that trigger underpinning quantitative traits. By contrast, genomewide selection estimates marker effects across the whole genome on the target population based on a prediction model developed in the training population (TP). Whole-genome prediction models estimate all marker effects in all loci and capture small QTL effects. Here, we review several genomic selection (GS) models with respect to both the prediction accuracy and genetic gain from selection. Phenotypic selection or markerassisted breeding protocols can be replaced by selection, based on whole-genome predictions in which phenotyping updates the model to build up the prediction accuracy.
11.
12.
Ghasemkhani, Marjan
(författare)
Genetic basis for resistance against fruit tree canker in apple
2012
Rapport (övrigt vetenskapligt/konstnärligt) abstract
Neonectria ditissima (formerly Neonectria galligena, anamorph Cylindrocarpon heteronema) is the causal agent of fruit tree canker which is regarded as a serious economic problem in horticulture. This fungus causes notable damage to apple trees and it is very important in some regions, especially North western Europe, where it can result in death of spur shoots and branches. Although it occurs in a wide range of temperatures, it is associated with wet weather and climate has an important effect on the geographic distribution. The fungus produces conidia and ascospores, both of which are dispersed and cause infection during prolonged periods of rainy weather. Also, spores produced on the infected wood can act as an infection source in the orchards. The fungus can therefore be introduced into new orchards with infected planting material from other orchards or tree nurseries. Chemical and mechanical control like spraying of fungicides, covering wounds with paint, and cutting out infected branches, do not prevent the occurrence of epidemics. Breeding cultivars with a high level of resistance towards canker would be of great help towards the avoidance of this disease. Apple cultivars show variable levels of partial resistance to the fungus, whereas complete resistance has not yet been reported and no major genes have been identified. Therefore, apple genotypes with comparatively high levels of genetically determined partial resistance should be identified for use in apple breeding.
13.
Hegay, Sergay
(författare)
Diversity of beans grown in Kyrgyzstan and marker-aided breeding for resistance to Bean common mosaic virus and anthracnose
2013
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Common bean (Phaseolus vulgaris L.) is an important export crop in Kyrgyzstan since the end of the 20th century. Kyrgyzstan produces about 70,000 t of common beans per year, which provides jobs to 76% of the population in the Talas region. Information about genetic diversity of common beans helps to select appropriate genetic material to be used for breeding programs. Accessions originating from both Mesoamerican and Andean gene pools, including the main Kyrgyz common bean market types were analyzed using simple sequence repeats (SSR) and qualitative morphological traits. The similarity matrices generated from the molecular and morphological data were well correlated (r = 0.49**). The cluster analysis of both data sets grouped the accessions according to their gene pools of origin, where Mesoamerican accessions were more diverse than Andean accessions. Both SSR and qualitative morphological markers were suitable for assigning cultivars to their gene pools of origin. Furthermore, information about traits of interest for Kyrgyz farmers has been gained. We found that Bean common mosaic virus strain NL6 and anthracnose affect this crop and reduce its grain yield significantly in Kyrgyzstan. The susceptible Kyrgyz cultivars Ryabaya, Kytayanka and Lopatka were included as recurrent parents in a backcrossing breeding scheme for introducing host plant resistance to these diseases from donor cultivars. After the 4th backcross, seeds (color, shape, size) and pods (shape) were similar to the respective recurrent parent. The sequence characterized amplified region (SCAR) markers SW13, SBD5 and SCAreoli were used successfully in marker-aided backcrossing for pyramiding the I, bc-12 and Co-2 genes, which provide host plant resistance to BCMV and anthracnose, respectively. Inoculation tests with anthracnose races delta and gamma, virus strain NL3, and DNA markers confirmed the presence of resistance genes in the offspring.
14.
Hörnblad, Emma
(författare)
Synthesis of glucuronoxylan in higher and lower plants : is there conservation of the enzymatic machinery?
2012
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The hemicellulose glucuronoxylan (GX) is the second most abundant polysaccharide after cellulose in the secondary cell walls of angiosperms and contributes significantly to the properties of wood as raw materials. Despite this, very little is known about the biosynthesis of hemicellulose. The thesis is based on studies performed in Physcomitrella patens, Arabidopsis thaliana, and Populus plants with the aim to increase the understanding of glucuronoxylan synthesis, and with main focus on the role of the IRX10 gene family. A number of genes have proven to be involved in GX biosynthesis in Arabidopsis, namely IRREGULAR XYLEM (IRX) 9, IRX14, IRX8, FRAGILE FIBER (FRA) 8 and PARVUS. This thesis presents two new genes, IRX10 and its close homolog IRX10- LIKE (L), which can now be added to the group of presumed GX biosynthesis genes. In addition, identification and characterisation of three homologs (IRX9-L, IRX14-L and F8H) of previously identified GX synthesis genes is described. Complementation experiments and morphological studies confirmed redundancy between the IRX9 and IRX9-L, IRX14 and IRX14-L, and the FRA8 and F8H pairs of genes in Arabidopsis. A bioinformatics based approach has led to the identification of four putative homologs in Populus trichocarpa (PtGT47A-1, PtGT47A-2, PtGT47D-1, and PtGT47D-4) of AtIRX10, and one putative homolog from Physcomitrella (PpGT47D). Experiments further confirmed functional conservation between the Arabidopsis (IRX10) and Populus GT47A proteins, and partial functional conservation between the Populus GT47D, the Physcomitrella GT47D and Arabidopsis IRX10 proteins. The work supports the existence of an Arabidopsis GX backbone biosynthesis complex in which AtIRX10 and AtIRX10-L form an essential component together with AtIRX9 and AtIRX14. It also suggests that parts of the GX biosynthesis machinery are conserved across embryophytes. Finally, work presented in this thesis indicates that the IRX10 gene family has gone through a subfunctionalisation event during the evolution.
15.
Lehrman, Anna, et al.
(författare)
Framtidens mat - om husdjursavel och växtförädling
2014
Bok (övrigt vetenskapligt/konstnärligt) abstract
Du har kanske inte funderat över varför tomater ser ut som de gör, varför våra husdjur är så lugna och vänliga, eller hur det är möjligt att köpa en vattenmelon utan kärnor. Trots att växtförädling och djuravel har format det mesta vi äter, är det få människor som är medvetna om vilka vetenskapliga upptäckter och vilket omfattande arbete som ligger bakom maten vi lägger på våra tallrikar. Med den här boken vill vi ge en översikt över domesticeringens och förädlingens bakgrund, från jordbrukets början för mer än 10 000 år sedan till dagens molekylära arbete. Vi beskriver grunderna för genernas strukturer och funktioner, varför och hur olika avels- och förädlingsmetoder används och ger en inblick i lagstiftningen kring användning av genteknik i Sverige och EU. Vi ger också en överblick över olika produkter som tagits fram genom genetisk modifiering (GM) och en sammanfattning av de ekonomiska konsekvenserna av GM-grödor. Vidare diskuterar vi etiska frågor som rör avel och förädling i allmänhet och genetisk modifiering i synnerhet.
16.
Leonova, Svetlana
(författare)
Lipids in seeds of oat (Avena spp.), a potential oil crop : content, quality, metabolism, and possibilities for improvement
2013
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
New oil crops with high yield and oil content are urgently needed. Oat is the only cereal that accumulates substantial amount of lipids in the endosperm. This gives it potential as an oil crop, which could address both nutritional and environmental concerns of modern society. To develop oat with increased oil content, thorough investigations on its lipid metabolism and tools for genetic manipulations are needed. Analyses of lipids in seeds of wild and cultivated oat species revealed variation in wild oat accessions in both oil content and quality. This variation should allow for development of new oat varieties for diverse applications. However, to develop oat as an oil crop, a level of 20% of the seed dry weight as oil is required and the range of oil content in the studied accessions was 4-10%. Another feature which showed almost no deviation was the amount of omega 3 fatty acid, -linolenic acid (0.6-2.1%). To develop oat varieties with ultra-high seed oil and increased content of omega 3 fatty acids, a biotechnological approach is preferred to conventional breeding methods. Lipids in oat endosperm have been reported to exist, not enclosed in oil bodies, but as non-structured oil smear. In my study, I also observed oil smears, a phenomenon probably correlated with the reduced amount of oil body associated proteins in the endosperm, as revealed by microscopic and staining methods. This was supported experimentally by SDS-PAGE separation of oil-body proteins and immunoblotting and immunolocalization with antibodies against a 16 kD oil body protein. Biochemical studies on lipid mobilization during oat seed germination demonstrated efficient utilization of oil reserves from the starchy endosperm; these results were corroborated by microscopy. An oat cultivar which is capable of accumulating high amounts of oil in the endosperm was shown to be also efficient in utilizing these reserves upon germination. Agrobacterium-mediated transformation is one of the methods for modification of oat oil content and/or its quality. The results of the analyses aimed at development of an Agrobacterium-mediated oat transformation protocol are presented in this thesis.
17.
Niazi, Adnan, et al.
(författare)
Genome Analysis of Bacillus amyloliquefaciens Subsp. plantarum UCMB5113: A Rhizobacterium That Improves Plant Growth and Stress Management
2014
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9
Tidskriftsartikel (refereegranskat) abstract
The Bacillus amyloliquefaciens subsp. plantarum strain UCMB5113 is a Gram-positive rhizobacterium that can colonize plant roots and stimulate plant growth and defense based on unknown mechanisms. This reinforcement of plants may provide protection to various forms of biotic and abiotic stress. To determine the genetic traits involved in the mechanism of plantbacteria association, the genome sequence of UCMB5113 was obtained by assembling paired-end Illumina reads. The assembled chromosome of 3,889,532 bp was predicted to encode 3,656 proteins. Genes that potentially contribute to plant growth promotion such as indole-3-acetic acid (IAA) biosynthesis, acetoin synthesis and siderophore production were identified. Moreover, annotation identified putative genes responsible for non-ribosomal synthesis of secondary metabolites and genes supporting environment fitness of UCMB5113 including drug and metal resistance. A large number of genes encoding a diverse set of secretory proteins, enzymes of primary and secondary metabolism and carbohydrate active enzymes were found which reflect a high capacity to degrade various rhizosphere macromolecules. Additionally, many predicted membrane transporters provides the bacterium with efficient uptake capabilities of several nutrients. Although, UCMB5113 has the possibility to produce antibiotics and biosurfactants, the protective effect of plants to pathogens seems to be indirect and due to priming of plant induced systemic resistance. The availability of the genome enables identification of genes and their function underpinning beneficial interactions of UCMB5113 with plants.
18.
Ortiz Rios, Rodomiro Octavio
(författare)
Advances in Transgenic Vegetable and Fruit Breeding
2014
Ingår i: Agricultural Sciences. - : Scientific Research Publishing, Inc.. - 2156-8553 .- 2156-8561. ; 5, s. 1448-1467
Tidskriftsartikel (refereegranskat) abstract
Vegetables and fruits are grown worldwide and play an important role in human diets because they provide vitamins, minerals, dietary fiber, and phytochemicals. Vegetables and fruits are also associated with improvement of gastrointestinal health, good vision, and reduced risk of heart disease, stroke, chronic diseases such as diabetes, and some forms of cancer. Vegetable and fruit production suffers from many biotic stresses caused by pathogens, pests, and weeds and requires high amounts of plant protection products per hectare. United States vegetables farmers are benefiting from growing transgenic squash cultivars resistant to Zucchini yellow mosaic virus , Watermelon mosaic virus , and Cucumber mosaic virus , which were deregulated and commercialized since 1996. Bt- sweet corn has also proven effective for control of some lepidopteran species and continues to be accepted in the fresh market in the USA, and Bt- fresh-market sweet corn hybrids are released almost every year. Likewise, transgenic Bt- eggplant bred to reduce pesticide use is now grown by farmers in Bangladesh. Transgenic papaya cultivars carrying the coat-protein gene provide effective protection against Papaya ring spot virus elsewhere. The transgenic “Honey Sweet” plum cultivar provides an interesting germplasm source for Plum pox virus control. Enhanced host plant resistance to Xanthomonas campestris pv. musacearum , which causes the devastating banana Xanthomonas wilt in the Great Lakes Region of Africa, was achieved by plant genetic engineering. There are other vegetable and fruit crops in the pipeline that have been genetically modified to enhance their host plant resistance to insects and plant pathogens, to show herbicide tolerance, and to improve features such as slow ripening that extends the shelf-life of the produce. Consumers could benefit further from eating more nutritious transgenic vegetables and fruits. Transgenic plant breeding therefore provides genetically enhanced seed embedded technology that contributes to integrated pest management in horticulture by reducing pesticide sprays as well as improving food safety by minimizing pesticide residues. Furthermore, herbicide-tolerant transgenic crops can help reducing plough in fields, thereby saving fuel because of less tractor use, which also protects the structure of the soil by reducing its erosion. Transgenic vegetable and fruit crops could make important contributions to sustainable vegetable production and for more nutritious and healthy food. Countries vary, however, in their market standards of acceptance of transgenic crops. Biotechnology products will be successful if clear advantages and safety are demonstrated to both growers and consumers
19.
20.
Ortiz Rios, Rodomiro Octavio
(författare)
Marker-aided breeding revolutionizes twenty-first century crop improvement
2012
Ingår i: Seed development: omics technologies toward improvement of seed quality and crop yield. - Dordrecht : Springer Netherlands. - 9789400747487 ; , s. 435-452
Bokkapitel (övrigt vetenskapligt/konstnärligt) abstract
The ever increasing human population always needs more healthy and nutritious food, produced in environmentally sustainable ways. Marker-aided breeding significantly contributes towards this priority goal. Molecular markers are mainly identifiable DNA sequences present in the genome and follow the Mendelian inheritance. In present time, a broad range of molecular markers are available for various crops. Advances in crop genome sequencing, high resolution genetic mapping, and precise phenotyping largely help the discovery of functional alleles and allelic variation associated with traits of interest for plant breeding. This chapter provides a brief overview on DNA markers and their use in crop breeding with examples in rice (as the model for inbreeding species) and maize (as an out-crossing species). Molecular marker-aided breeding undoubtedly speeds the conventional breeding process and makes crop improvement more precise. Availability of physical maps, genomes sequences, and high-throughput technologies will also facilitate in developing new molecular breeding approaches in this twenty-first century.
21.
Ortiz Rios, Rodomiro Octavio
(författare)
New quantitative trait loci for enhancing adaptation to salinity in rice from Hasawi, a Saudi landrace into three African cultivars at the reproductive stage
2014
Ingår i: Euphytica. - : Springer Science and Business Media LLC. - 0014-2336 .- 1573-5060. ; 200, s. 45-60
Tidskriftsartikel (refereegranskat) abstract
Salinity is a major constraint affecting rice productivity in rainfed and irrigated agro-ecosystems. Understanding salinity effects on rice production at the reproductive stage could improve adaptation for this trait. Identifying quantitative trait loci (QTLs) controlling adaptation to salinity may also accelerate breeding rice germplasm for environments prone to this stress. We used the salt tolerant landrace 'Hasawi' as a donor parent to generate three F-2 offspring (consisting each of 500 individuals) with three African cultivars ('NERICA-L-19', 'Sahel 108' and 'BG902') used as recipient parents (RP). The F(2)s and F(2:3)s were evaluated for grain yield and other traits in saline fields. Salinity caused reduction in all measured traits across the F-2-derived offspring, e. g. grain yield reduced between 65 and 73 %, but some offspring had twice the RP's grain yield. QTL analysis revealed 75 QTLs for different traits in all 3 genetic backgrounds (GBs): 24 of them were common among all the 3 GBs while 31 were noted in 2 GBs, and 17 in one GB. 'Hasawi' contributed on average 49 % alleles to these QTLs. Two yield and yield related QTLs (qGY11 and qTN11) common in all 3 GBs were mapped on the same chromosomal segment suggesting these QTLs might be stable across different GBs. Four other QTLs were strongly associated with salinity tolerance with peak marker RM419, representing a potential candidate for MAS due to high LOD score and relatively large effect QTLs.
22.
Ortiz Rios, Rodomiro Octavio
(författare)
Peanut improvement for human health
2014
Ingår i: Plant Breeding Reviews: Volume 38. - Hoboken, New Jersey : John Wiley & Sons, Inc.. - 9781118916834 ; 38, s. 143-185
Bokkapitel (refereegranskat) abstract
Peanut (Arachis hypogaea L., Fabaceae) is an energy-dense and nutritious food. Regular consumption of peanuts improves human health. Oil content and oil quality, which is determined by variation in oleic (O) and linoleic (L) fatty acids, are important seed quality traits in peanut. Aflatoxin (produced by fungus Aspergillus flavus and Aspergillus parasiticus) is a serious health problem, whereas peanut allergy is a potentially life-threatening and often lifelong food allergy. High O/L ratio increases shelf life of peanut products and, therefore, their marketability. Germplasm and advanced breeding lines with oil content as high as 55–60% and O/L ratio ranging from 7:1 to 40:1 are available for use in peanut breeding. Global warming has a significant impact on the nutritional quality of food crops. Identification of germplasm with stable seed quality traits will be a prerequisite to initiate quality breeding in peanut. Peanut cultivars with high oleate content, developed by conventional breeding and selection, are widely grown in the United States. Marker-aided backcross breeding has led to the development of ‘Tifguard High O/L’ peanut cultivar in the United States. Enough genetic variation in seed iron and zinc content has been noted, but targeted breeding for these micronutrients in peanut is yet to begin. Peanut is devoid of β-carotene—a precursor of vitamin A. Using a cotyledon-based Agrobacterium-mediated genetic transformation system and the maize psyI gene driven by the At oleosin promoter, β-carotene-rich transgenic peanuts have been achieved. Transgenic peanuts with the antifungal gene cpo-p inhibited A. flavus hyphal growth or those containing the Rchit gene have shown a broader spectrum of resistance against fungal infection including A. flavus. Knocking out genes for the allergenic proteins, using targeting-induced local lesions in genomes (TILLING) or RNAi approaches, has shown promise to derive mutants or transgenic events lacking allergenic seed proteins, with no adverse effect on seed quality or viability. These genetic stocks when available to researchers may lead to breeding agronomically superior nutritionally enhanced peanut cultivars, which will be free from allergens and toxins.
23.
Ortiz Rios, Rodomiro Octavio
(författare)
Plant prebiotics and human health: Biotechnology to breed prebiotic-rich nutritious food crops
2014
Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 17, s. 238–245-
Forskningsöversikt (refereegranskat) abstract
Microbiota in the gut play essential roles in human health. Prebiotics are non-digestible complex carbohydrates that are fermented in the colon, yielding energy and short chain fatty acids, and selectively promote the growth of Bifidobacteria and Lactobacillae in the gastro-intestinal tract. Fructans and inulin are the best-characterized plant prebiotics. Many vegetable, root and tuber crops as well as some fruit crops are the best-known sources of prebiotic carbohydrates, while the prebiotic-rich grain crops include barley, chickpea, lentil, lupin, and wheat. Some prebiotic-rich crop germplasm have been reported in barley, chickpea, lentil, wheat, yacon, and Jerusalem artichoke. A few major quantitative trait loci and gene-based markers associated with high fructan are known in wheat. More targeted search in genebanks using reduced subsets (representing diversity in germplasm) is needed to identify accessions with prebiotic carbohydrates. Transgenic maize, potato and sugarcane with high fructan, with no adverse effects on plant development, have been bred, which suggests that it is feasible to introduce fructan biosynthesis pathways in crops to produce health-imparting prebiotics. Developing prebiotic-rich and super nutritious crops will alleviate the widespread malnutrition and promote human health. A paradigm shift in breeding program is needed to achieve this goal and to ensure that newly-bred crop cultivars are nutritious, safe and health promoting. (C) 2014 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V. All rights reserved.
24.
Pham, Toan Duc
(författare)
Analyses of genetic diversity and desirable traits in sesame (Sesamum indicum L., Pedaliaceae) : implication for breeding and conservation
2011
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Sesame (Sesamum indicum L., Pedaliaceae) is a traditional oil crop cultivated in Vietnam and Cambodia. It is known as the king of oil seeds in Vietnam due to the high oil content (50-60%) in its seed. Yet, the insufficient genetic information regarding Vietnamese and Cambodian sesame populations is limiting the access to useful traits present among adapted landraces in this region. The purpose of this study was to characterize various sesame accessions to gain information that could help design strategies for future breeding program and conservation of this crop in the two countries. Morphological and molecular markers as well as oil content and quality analyses were employed to evaluate sesame accessions from different sources. High genetic variation was found among populations of sesame collected in Vietnam and Cambodia. The two type of markers, morphological and molecular, were both useful in analyzing the extent of genetic diversity in sesame and the result of these analyses will help to better understand the genetic diversity and relationship within and among populations. Overall, the sesame accessions included in the study showed a correlation with their geographical origins such that accessions from the same region tended to have higher genetic similarity as compared to those from different regions. However, when cluster analysis was applied to evaluate the genetic relationship, some sesame accessions were found not to be grouped based on geographical origins. This contrasting result could perhaps be a result from the exchange over time, of sesame germplasm, between farmers across the regions. The results from morphological and oil content analyses showed that several sesame accessions in Southern Vietnam and Cambodia displayed a good potential for high seed yield and oil content. Overall, the studies in this thesis provide important insights into the populations of sesame in Vietnam and Cambodia and constitute a set of useful background information that can be used as a basis for future breeding strategy and improvement of sesame in this region.
25.
Ramesh, Vetukuri, et al.
(författare)
Evidence for Small RNAs Homologous to Effector-Encoding Genes and Transposable Elements in the Oomycete Phytophthora infestans
2012
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:12, s. e51399-
Tidskriftsartikel (refereegranskat) abstract
Phytophthora infestans is the oomycete pathogen responsible for the devastating late blight disease on potato and tomato. There is presently an intense research focus on the role(s) of effectors in promoting late blight disease development. However, little is known about how they are regulated, or how diversity in their expression may be generated among different isolates. Here we present data from investigation of RNA silencing processes, characterized by non-coding small RNA molecules (sRNA) of 19-40 nt. From deep sequencing of sRNAs we have identified sRNAs matching numerous RxLR and Crinkler (CRN) effector protein genes in two isolates differing in pathogenicity. Effector gene-derived sRNAs were present in both isolates, but exhibited marked differences in abundance, especially for CRN effectors. Small RNAs in P. infestans grouped into three clear size classes of 21, 25/26 and 32 nt. Small RNAs from all size classes mapped to RxLR effector genes, but notably 21 nt sRNAs were the predominant size class mapping to CRN effector genes. Some effector genes, such as PiAvr3a, to which sRNAs were found, also exhibited differences in transcript accumulation between the two isolates. The P. infestans genome is rich in transposable elements, and the majority of sRNAs of all size classes mapped to these sequences, predominantly to long terminal repeat (LTR) retrotransposons. RNA silencing of Dicer and Argonaute genes provided evidence that generation of 21 nt sRNAs is Dicer-dependent, while accumulation of longer sRNAs was impacted by silencing of Argonaute genes. Additionally, we identified six microRNA (miRNA) candidates from our sequencing data, their precursor sequences from the genome sequence, and target mRNAs. These miRNA candidates have features characteristic of both plant and metazoan miRNAs.
26.
Roos, Jonas
(författare)
Verticillium longisporum and plant immunity responses in Arabidopsis
2014
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Verticillium spp. are soil-borne ascomycete fungi belonging to a subgroup of Sordariomycetes, and the three major plant pathogens Verticillium longisporum, V. dahliae and V. albo-atrum cause disease on numerous plant species worldwide. In Sweden, V. longisporum poses a threat to Brassica oilseed crops, and is thus emphasized in this thesis. Here the early immune responses to V. longisporum in the model plant Arabidopsis and recent data on the V. longisporum genome are presented. Three genes of importance in the Arabidopsis–V. longisporum interaction were studied. The genes were identified via transcriptome and single nucleotide polymorphism (SNP) analysis. RabGAP22, a RabGTPase-regulating protein, was found to contribute to V. longisporum resistance. Pull-down assays revealed SERINE:GLYOXYLATE AMINOTRANSFERASE (AGT1) as an interacting partner during V. longisporum infection and the two proteins were shown to co-localize in the peroxisomes. Unexpectedly, a role for RabGAP22 was also found in stomatal immunity. The monoterpene synthase TPS23/27 was on the other hand found to contribute to fungal invasion, by triggering germination of V. longisporum conidia. The third gene codes for a nitrate/peptide transporter, NPF5.12. Pull-down experiments and fluorescent imaging revealed interaction between NPF5.12 and a major latex protein family member, NPFBP1. Implications in plant immunity processes of these three genes are further discussed. The genomes of two Swedish V. longisporum isolates were sequenced and found to have a size of approximately 70 Mb and harbor ~21,000 protein-coding genes. Initial analyses revealed that 86% of the V. longisporum genomes are shared with V. dahliae and V. albo-atrum, with a high extent of gene duplications. Large numbers of proteins were predicted to contain secretion motifs, and this group of proteins is presumed to play major roles in the interactions with V. longisporum host plants. In conclusion, this thesis work has revealed new fungal and plant host genes and thereby laid the basis for new plant breeding and disease protection strategies.
27.
Sattar, Muhammad Naeem, et al.
(författare)
Cotton leaf curl disease - an emerging threat to cotton production worldwide
2013
Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 94, s. 695-710
Forskningsöversikt (refereegranskat) abstract
Cotton leaf curl disease (CLCuD) is a serious disease of cotton which has characteristic symptoms, the most unusual of which is the formation of leaf-like enations on the undersides of leaves. The disease is caused by whitefly-transmitted geminiviruses (family Geminiviridae, genus Begomovirus) in association with specific, symptom-modulating satellites (betasatellites) and an evolutionarily distinct group of satellite-like molecules known as alphasatellites. CLCuD occurs across Africa as well as in Pakistan and north-western India. Over the past 25 years, Pakistan and India have experienced two epidemics of the disease, the most recent of which involved a virus and satellite that are resistance breaking. Loss of this conventional host-plant resistance, which saved the cotton growers from ruin in the late 1990s, leaves farmers with only relatively poor host plant tolerance to counter the extensive losses the disease causes. There has always been the fear that CLCuD could spread from the relatively limited geographical range it encompasses at present to other cotton-growing areas of the world where, although the disease is not present, the environmental conditions are suitable for its establishment and the whitefly vector occurs. Unfortunately recent events have shown this fear to be well founded, with CLCuD making its first appearance in China. Here, we outline recent advances made in understanding the molecular biology of the components of the disease complex, their interactions with host plants, as well as efforts being made to control CLCuD.
28.
29.
Turesson, Helle
(författare)
Carbon allocation in underground storage organs : studies on accumulation of starch, sugars and oil
2014
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
By increasing knowledge of carbon allocation in underground storage organs and using the knowledge to improve such crops, the competitiveness of these types of storage organs can be strengthened. Starch is the most common storage compound in tubers and roots, but some crops accumulate compounds other than starch. This thesis examined representative underground storage organs accumulating starch, oil and sugars. These were: the oil-accumulating nutsedge (Cyperus esculentus), a half-grass which possesses the unusual ability to accumulate triacylglycerol in considerable levels in small tubers physiologically resembling those of potato; the sucrose-storing taproot of sugar beet (Beta vulgaris); and the starch- and sugar-storing taproot of parsnip (Pastinaca sativa). The lack of starch formation in sugar beet was examined in relation to expression of starch biosynthesis-related genes and enzymes in the taproot. In parallel studies on potato (Solanum tuberosum), a classical starch accumulator, two different transgenic approaches to alter the metabolism and starch biosynthesis of tubers were tested. A novel finding was that expression of the oil transcription factor WRINKLED1 in potato tubers resulted in tubers accumulating oil and negatively affected starch biosynthesis. The oil-accumulating potato tubers shared structural similarities with young nutsedge. Assays on the transcriptome of sugar beet and parsnip revealed that transcripts of two plastidial genes responsible for energy import and phosphate hydrolysis were lower in sugar beet than in parsnip, indicating potential importance for starch accumulation. In potato, the importance of these two genes was assayed by silencing the genes. The outcome was potato tubers with severely affected starch biosynthesis, granule morphology, tuber yield, tuberisation and starch quality, confirming that the silenced genes play an important role in starch biosynthesis in potato tubers.
30.
Turesson, Helle, et al.
(författare)
Starch biosynthetic genes and enzymes are expressed and active in the absence of starch accumulation in sugar beet tap-root
2014
Ingår i: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 14
Tidskriftsartikel (refereegranskat) abstract
Abstract Background: Starch is the predominant storage compound in underground plant tissues like roots and tubers. An exception is sugar beet tap-root (Beta vulgaris ssp altissima) which exclusively stores sucrose. The underlying mechanism behind this divergent storage accumulation in sugar beet is currently not fully known. From the general presence of starch in roots and tubers it could be speculated that the lack in sugar beet tap-roots would originate from deficiency in pathways leading to starch. Therefore with emphasis on starch accumulation, we studied tap-roots of sugar beet using parsnip (Pastinaca sativa) as a comparator. Results: Metabolic and structural analyses of sugar beet tap-root confirmed sucrose as the exclusive storage component. No starch granules could be detected in tap-roots of sugar beet or the wild ancestor sea beet (Beta vulgaris ssp. maritima). Analyses of parsnip showed that the main storage component was starch but tap-root tissue was also found to contain significant levels of sugars. Surprisingly, activities of four main starch biosynthetic enzymes, phosphoglucomutase, ADP-glucose pyrophosphorylase, starch synthase and starch branching enzyme, were similar in sugar beet and parsnip tap-roots. Transcriptional analysis confirmed expression of corresponding genes. Additionally, expression of genes involved in starch accumulation such as for plastidial hexose transportation and starch tuning functions could be determined in tap-roots of both plant species. Conclusion: Considering underground storage organs, sugar beet tap-root upholds a unique property in exclusively storing sucrose. Lack of starch also in the ancestor sea beet indicates an evolved trait of biological importance. Our findings in this study show that gene expression and enzymatic activity of main starch biosynthetic functions are present in sugar beet tap-root during storage accumulation. In view of this, the complete lack of starch in sugar beet tap-roots is enigmatic.
31.
Zubair, Muhammad
(författare)
Genetic variation, biochemical contents and wound healing activity of Plantago major
2012
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Plantago major L. (greater plantain, common plantain) has been used as a wound healing remedy in different parts of the world for centuries. Different bioactive compounds have been proposed to contribute to the wound healing properties of this plant. The present study was undertaken to investigate the impact of some genetic and environmental factors on the wound healing activity of common plantain. Seeds of P. major were collected from five populations in different parts of Sweden, and were germinated and grown in a greenhouse. As expected for an inbreeding species, RAPD analyses demonstrated considerable between-population variation but very sparse within-population and within-subpopulation variation. Six major phenolic compounds were encountered in samples of P. major, four of which were identified for the first time in this thesis; PLMA 1–PLMA 4. Between-population and sub-population differences in the contents of these chemical compounds showed no correlation with RAPD-based estimates of genetic relatedness. The contents of these compounds differed greatly between different plant organs of P. major. The highest concentration of plantamajoside and PLMA 2 was found in leaves whereas the highest concentration of verbascoside was found in flower stalks and seeds. Contents were significantly higher in freeze-dried leaf samples compared to samples dried at higher temperatures. Both water and ethanol-based extracts of P. major leaves stimulated the cell proliferation and migration in an in vitro scratch assay, and also showed anti-inflammatory activity in an in vitro NF-kB assay with oral epithelial cell cultures. Similarly, these extracts stimulated wound healing activities in ex vivo tests using detached pig ears. Further breeding efforts aimed at developing P. major as a crop plant, and medicinal research aimed at elucidating and optimizing extracts with wound healing properties, are thus warranted.
32.
33.
34.
Cierlik, Izabela
(författare)
Novel insights into the action of SHI/STY transcriptional regulators during plant development
2014
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
One key player in plant organogenesis is the phytohormone auxin, and this thesis reveal that members of the SHI/STY gene family participate in the regulation of auxin homeostasis and organ development in Arabidopsis thaliana. Using inducible constructs, ChIP, and EMSA, we could show that the SHI/STY members act as transcriptional activators directly binding to the promoter of the auxin biosynthesis gene YUC4. Additional putative downstream targets were identified encoding transcription factors, other auxin biosynthesis enzymes and enzymes involved in cell wall modulations. This work also brings novel insight into SHI/STY-dependent regulation of cotyledon and leaf vascular patterning and stamen number. Detailed expression studies of SHI/STY genes and several downstream targets confirm their overlapping spatial and temporal expression pattern during cotyledon, leaf, stamen and gynoecium development, clearly supporting the partially redundant function of the SHI/STY family members during the development of these organs. In addition, the expression of SHI/STY members is partially mediated through a conserved motif in their promoter region, a GCC-box, which appears to be essential for SHI/STY expression in aerial organs. Furthermore, a group of putative upstream regulators belonging to the AP2/ERF family have been identified, which requires the GCC-box for their transcriptional regulation of the SHI/STY genes.
35.
Jäderkvist Fegraeus, Kim, et al.
(författare)
The DMRT3 'Gait keeper' mutation affects performance of Nordic and Standardbred trotters
2014
Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 92:10, s. 4279-4286
Tidskriftsartikel (refereegranskat) abstract
In a previous study it was shown that a nonsense mutation in the DMRT3 gene alters the pattern of locomotion in horses and that this mutation has a strong positive impact on trotting performance of Standardbreds. One aim of this study was to test if racing performance and trotting technique in the Nordic (Coldblood) trotters are also influenced by the DMRT3 genotype. Another aim was to further investigate the effect of the mutation on performance in Standardbreds, by using a within-family analysis and genotype-phenotype correlations in a larger horse material than in the previous study. We genotyped 427 Nordic trotters and 621 Standardbreds for the DMRT3 nonsense mutation and a SNP in strong linkage disequilibrium with it. In Nordic trotters, we show that horses homozygous for the DMRT3 mutation (A) had significantly higher EBV for trotting performance traits than heterozygous (CA) or homozygous wild-type (CC) horses (P = 0.001). Furthermore, AA homozygotes had a higher proportion of victories and top 3 placings than horses heterozygous or homozygous wild-type, when analyzing performance data for the period 3 to 6 yr of age (P = 0.06 and P = 0.05, respectively). Another finding in the Nordic trotters was that the DMRT3 mutation influenced trotting technique (P = 2.1 x 10(-8)). Standardbred horses homozygous AA had significantly higher EBV for all traits than horses with at least 1 wild-type allele (CA and CC; P = 1.6 x 10(-16)). In a within-family analysis of Standardbreds, we found significant differences in several traits (e. g., earnings, P = 0.002; number of entered races, P = 0.004; and fraction of offspring that entered races, P = 0.002) among paternal half-sibs with genotype AA or CA sired by a CA stallion. For most traits, we found significant differences at young ages. For Nordic trotters, most of the results were significant at 3 yr of age but not for the older ages, and for the Standardbreds most of the results for the ages 3 to 5 were significant. For Nordic trotters, the proportion of victories and placings were the only traits that were significant for other ages than 3 yr.
36.
Ortiz Rios, Rodomiro Octavio
(författare)
Drought tolerance
2013
Ingår i: Genomics and Breeding for Climate-Resilient Crops: vol. 2 Target Traits. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642370472 ; , s. 203-223
Bokkapitel (refereegranskat)
37.
38.
Ahlgren, Kerstin M, et al.
(författare)
Lack of evidence for a role of islet autoimmunity in the aetiology of canine diabetes mellitus
2014
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8, s. e105473-
Tidskriftsartikel (refereegranskat) abstract
AIMS/HYPOTHESIS:Diabetes mellitus is one of the most common endocrine disorders in dogs and is commonly proposed to be of autoimmune origin. Although the clinical presentation of human type 1 diabetes (T1D) and canine diabetes are similar, the aetiologies may differ. The aim of this study was to investigate if autoimmune aetiology resembling human T1D is as prevalent in dogs as previously reported.METHODS:Sera from 121 diabetic dogs representing 40 different breeds were tested for islet cell antibodies (ICA) and GAD65 autoantibodies (GADA) and compared with sera from 133 healthy dogs. ICA was detected by indirect immunofluorescence using both canine and human frozen sections. GADA was detected by in vitro transcription and translation (ITT) of human and canine GAD65, followed by immune precipitation. Sections of pancreata from five diabetic dogs and two control dogs were examined histopathologically including immunostaining for insulin, glucagon, somatostatin and pancreas polypeptide.RESULTS:None of the canine sera analysed tested positive for ICA on sections of frozen canine or human ICA pancreas. However, serum from one diabetic dog was weakly positive in the canine GADA assay and serum from one healthy dog was weakly positive in the human GADA assay. Histopathology showed marked degenerative changes in endocrine islets, including vacuolisation and variable loss of immune-staining for insulin. No sign of inflammation was noted.CONCLUSIONS/INTERPRETATIONS:Contrary to previous observations, based on results from tests for humoral autoreactivity towards islet proteins using four different assays, and histopathological examinations, we do not find any support for an islet autoimmune aetiology in canine diabetes mellitus.
39.
Ahlman, Therese, et al.
(författare)
Differences in preferences for breeding traits between organic and conventional dairy producers in Sweden
2014
Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 162, s. 5-14
Tidskriftsartikel (refereegranskat) abstract
Development of sustainable breeding goals for dairy production has to consider the producers' preferences which are likely to differ between production systems. The number of dairy producers with herds certified according to the standards of organic production has increased during the last decades. Traditionally, organic producers use animals selected in conventional production systems but the traits important in organic herds have been suggested to differ due to the different production conditions. The aim of this study was to assess what traits Swedish organic and conventional daily producers consider to be important for the cows in their herds, and the relative importance of traits in the two production systems.An advanced web questionnaire with an underlying selection index was developed. The selection index was not shown to the respondents but it enabled them to weight traits against each other based on the genetic progress obtained. The questionnaire also included questions about what traits the producers intuitively considered important for the cows in their herds and how they ranked 15 given production and functional traits. The questionnaire was answered by 468 Swedish dairy producers of which 122 had a certified organic herd and 346 had a conventional herd.The results of this study show that the trait longevity was ranked first by both organic and conventional Swedish dairy producers. However, the ranking differed to some extent between the production systems for other traits, e.g. mastitis resistance and milk production. Swedish producers with organic herds tended to desire a higher genetic gain in disease resistance, including mastitis and parasite resistance, compared with producers with conventional herds. The results also reflect a somewhat lower interest in milk production level among producers with organic production. However, as the traits most important for Swedish producers with organic herds are already considered in the current Nordic breeding goal they can continue the use of this animal material. (C) 2014 The Authors. Published by Elsevier B.V.
40.
41.
Ahlman, Therese, et al.
(författare)
Organic producers' preferences regarding traits important in dairy production
2012
Ingår i: Landbauforschung Völkenrode. Sonderheft. - 0376-0723. ; 362, s. 343-346
Konferensbidrag (refereegranskat) abstract
Much effort has been put on the development and promotion of organic dairy products, but little attention has been paid to the foundation of the production, i.e. the animal material. The process of developing sustainable breeding strategies, in agreement with the goals for organic production, should involve identification of traits especially important in organic production. The aim of this study is to identify organic and conventional producers' preferences regarding traits important in dairy production. A web based questionnaire has been developed and answered by 468 dairy farm-ers in Sweden (26 % organic producers). The results show that organic producers rank traits relat-ed to resistance to diseases higher than conventional producers, while milk production, lactation curve, temperament and claw and leg health were ranked higher by conventional farmers. This in-dicates a need for breeding goals adjusted to satisfy farmers with different type of production.
42.
43.
44.
Ali, Ashfaq, et al.
(författare)
Paranoid potato : phytophthora-resistant genotype shows constitutively activated defense
2012
Ingår i: Plant Signaling and Behavior. - : Informa UK Limited. - 1559-2316 .- 1559-2324. ; 7:3, s. 400-408
Tidskriftsartikel (refereegranskat) abstract
Phytophthora is the most devastating pathogen of dicot plants. There is a need for resistance sources with different modes of action to counteract the fast evolution of this pathogen. In order to better understand mechanisms of defense against P. infestans, we analyzed several clones of potato. Two of the genotypes tested, Sarpo Mira and SW93-1015, exhibited strong resistance against P. infestans in field trials, whole plant assays and detached leaf assays. The resistant genotypes developed different sizes of hypersensitive response (HR)-related lesions. HR lesions in SW93-1015 were restricted to very small areas, whereas those in Sarpo Mira were similar to those in Solanum demissum, the main source of classical resistance genes. SW93-1015 can be characterized as a cpr (constitutive expressor of PR genes) genotype without spontaneous microscopic or macroscopic HR lesions. This is indicated by constitutive hydrogen peroxide (H₂O₂) production and PR1 (pathogenesis-related protein 1) secretion. SW93-1015 is one of the first plants identified as having classical protein-based induced defense expressed constitutively without any obvious metabolic costs or spontaneous cell death lesions.
45.
46.
Alvarez-Castro, Jose, et al.
(författare)
Estimation and interpretation of genetic effects with epistasis using the NOIA model.
2012
Ingår i: Methods in Molecular Biology. - Totowa, NJ : Humana Press. - 1064-3745 .- 1940-6029. ; 871, s. 191-204
Tidskriftsartikel (refereegranskat) abstract
We introduce this communication with a brief outline of the historical landmarks in genetic modeling, especially concerning epistasis. Then, we present methods for the use of genetic modeling in QTL analyses. In particular, we summarize the essential expressions of the natural and orthogonal interactions (NOIA) model of genetic effects. Our motivation for reviewing that theory here is twofold. First, this review presents a digest of the expressions for the application of the NOIA model, which are often mixed with intermediate and additional formulae in the original articles. Second, we make the required theory handy for the reader to relate the genetic concepts to the particular mathematical expressions underlying them. We illustrate those relations by providing graphical interpretations and a diagram summarizing the key features for applying genetic modeling with epistasis in comprehensive QTL analyses. Finally, we briefly review some examples of the application of NOIA to real data and the way it improves the interpretability of the results.
47.
Alvarez-Castro, Jose, et al.
(författare)
Modelling of genetic interactions improves prediction of hybrid patterns : a case study in domestic fowl
2012
Ingår i: Genetical Research. - 0016-6723 .- 1469-5073. ; 94:5, s. 255-266
Tidskriftsartikel (refereegranskat) abstract
Summary A major challenge in complex trait genetics is to unravel how multiple loci and environmental factors together cause phenotypic diversity. Both first (F1) and second (F2) generation hybrids often display phenotypes that deviate from what is expected under intermediate inheritance. We have here studied two chicken F2 populations generated by crossing divergent chicken lines to assess how epistatic loci, identified in earlier quantitative trait locus (QTL) studies, contribute to hybrid deviations from the mid-parent phenotype. Empirical evidence suggests that the average phenotypes of the intercross birds tend to be lower than the midpoint between the parental means in both crosses. Our results confirm that epistatic interactions, despite a relatively small contribution to the phenotypic variance, play an important role in the deviation of hybrid phenotypes from the mid-parent values (i.e. multi-locus hybrid genotypes lead to lower rather than higher body weights). To a lesser extent, dominance also appears to contribute to the mid-parent deviation, at least in one of the crosses. This observation coincides with the hypothesis that hybridization tends to break up co-adapted gene complexes, i.e. generate Bateson-Dobzhansky-Muller incompatibilities.
48.
49.
Amuzu, Esinam, et al.
(författare)
Prediction of Heterosis in White Leghorn Crossbreds using Paternal 60K SNP Genotypes
2014
Annan publikation (övrigt vetenskapligt/konstnärligt) abstract
Predicting heterosis for crossbred offspring of individual sires would harness variation between sires from the same pure-line, and can increase the utilization of heterosis in crossbreeding schemes. We aimed to derive the theoretical expectation for heterosis in crossbred offspring of individual sires, and then predict heterosis for these offspring. We used 60K SNP-genotypes from 3427 sires, allele frequencies from 9 pure-lines, and egg number records from 16 crosses between those lines, representing ~210,000 crossbred hens. Results show that it is possible to predict heterosis at the sire level, thereby distinguishing between sires within the same pure-line whose offspring will show higher heterosis. However, variation in predicted heterosis between sires within a line was low in our data; most differences were seen between lines. A potential improvement of the method would be to base predictions on a subset of SNPs with identified effects on heterosis.
50.
Amuzu, Esinam
(författare)
Prediction of heterosis using genome-wide SNP-marker data: application to egg production traits in white Leghorn crosses
2013
Ingår i: Heredity. - : Springer Science and Business Media LLC. - 0018-067X .- 1365-2540. ; 111, s. 530-538
Tidskriftsartikel (refereegranskat) abstract
Prediction of heterosis has a long history with mixed success, partly due to low numbers of genetic markers and/or small data sets. We investigated the prediction of heterosis for egg number, egg weight and survival days in domestic white Leghorns, using B400 000 individuals from 47 crosses and allele frequencies on B53 000 genome-wide single nucleotide polymorphisms (SNPs). When heterosis is due to dominance, and dominance effects are independent of allele frequencies, heterosis is proportional to the squared difference in allele frequency (SDAF) between parental pure lines (not necessarily homozygous). Under these assumptions, a linear model including regression on SDAF partitions crossbred phenotypes into pure-line values and heterosis, even without pure-line phenotypes. We therefore used models where phenotypes of crossbreds were regressed on the SDAF between parental lines. Accuracy of prediction was determined using leave-one-out crossvalidation. SDAF predicted heterosis for egg number and weight with an accuracy of B0.5, but did not predict heterosis for survival days. Heterosis predictions allowed preselection of pure lines before field-testing, saving B50% of field-testing cost with only 4% loss in heterosis. Accuracies from cross-validation were lower than from the model-fit, suggesting that accuracies previously reported in literature are overestimated. Cross-validation also indicated that dominance cannot fully explain heterosis. Nevertheless, the dominance model had considerable accuracy, clearly greater than that of a general/specific combining ability model. This work also showed that heterosis can be modelled even when pure-line phenotypes are unavailable. We concluded that SDAF is a useful predictor of heterosis in commercial layer breeding.
