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.
