| 1. |
- Crous, P. W., et al.
(författare)
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Fusarium : more than a node or a foot-shaped basal cell
- 2021
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Ingår i: Studies in mycology. - : CENTRAALBUREAU SCHIMMELCULTURE. - 0166-0616 .- 1872-9797. ; :98
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Tidskriftsartikel (refereegranskat)abstract
- Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org).
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| 2. |
- Ernfors, Maria
(författare)
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Challenges of accounting nitrous oxide emissions from agricultural crop residues
- 2023
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Ingår i: Global Change Biology. - 1354-1013 .- 1365-2486. ; 29, s. 6846-6855
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Tidskriftsartikel (refereegranskat)abstract
- Crop residues are important inputs of carbon (C) and nitrogen (N) to soils and thus directly and indirectly affect nitrous oxide (N2O) emissions. As the current inventory methodology considers N inputs by crop residues as the sole determining factor for N2O emissions, it fails to consider other underlying factors and processes. There is compelling evidence that emissions vary greatly between residues with different biochemical and physical characteristics, with the concentrations of mineralizable N and decomposable C in the residue biomass both enhancing the soil N2O production potential. High concentrations of these components are associated with immature residues (e.g., cover crops, grass, legumes, and vegetables) as opposed to mature residues (e.g., straw). A more accurate estimation of the short-term (months) effects of the crop residues on N2O could involve distinguishing mature and immature crop residues with distinctly different emission factors. The medium-term (years) and long-term (decades) effects relate to the effects of residue management on soil N fertility and soil physical and chemical properties, considering that these are affected by local climatic and soil conditions as well as land use and management. More targeted mitigation efforts for N2O emissions, after addition of crop residues to the soil, are urgently needed and require an improved methodology for emission accounting. This work needs to be underpinned by research to (1) develop and validate N2O emission factors for mature and immature crop residues, (2) assess emissions from belowground residues of terminated crops, (3) improve activity data on management of different residue types, in particular immature residues, and (4) evaluate long-term effects of residue addition on N2O emissions.
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| 3. |
- Majaliwa, Nuria, 1980, et al.
(författare)
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Effect of cultivar and ripening on the polyphenol contents of East African highland bananas (Musa spp.)
- 2021
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Ingår i: International Food Research Journal. - 1985-4668 .- 2231-7546. ; 28:3, s. 479-488
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Tidskriftsartikel (refereegranskat)abstract
- East African highland bananas (EAHBs) contain high amount of phenolics especially tannins, and are used to produce low-viscosity banana juice by a purely mechanical process. Occasional juice failure and cloudy appearance are the major problems facing juice production. The present work thus examined the variations in phenolic content of EAHB cultivars and their changes during ripening. The aim was to obtain a better knowledge of the various forms and amounts of phenolic compounds in different EAHBs, and how these properties may affect the ability of cultivars to produce low viscosity banana juice. Eleven banana cultivars including juice-producing and cooking bananas were harvested at the green maturity stage and analysed for total phenolic content (TPC), tannin content (TC), and tannin monomers at different ripening stages for five days. Analyses of TPC and TC were performed using the Folin-Ciocalteu method, whereas tannin monomers were identified by High-Performance Liquid Chromatography (HPLC) with UV detection. Multivariate analysis of variance was used to evaluate the relationship between cultivar, ripeness stage, and TPC/TC. A substantial difference in TPC was observed between juice-producing and cooking cultivars. The highest TPC was found in the juice-producing cultivar Kibungara (360.68 +/- 17.12 mg GAE/100 g) at day 5 (the ripe stage), while the lowest TPC (8.67 +/- 0.22 mg GAE/100 g) was observed in the cooking cultivar Malindi at ripening day 5. The results revealed that TPC and TC of banana pulp seemed to be more related to cultivar (p <= 0.05) than physiological changes during ripening (p >= 0.05). Further, HPLC analysis showed that among the individual catechins, gallocatechin was the predominant monomer in juice-producing cultivars, whereas in cooking cultivars, gallic acid was dominant. The present work indicated that high amount of total phenolic such as tannins especially gallocatechin in juice-producing banana cultivars favour the release of banana juice, and that analysis of phenolic compounds will provide a basis in the selection of banana cultivars with high potential for juice production.
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| 4. |
- Nadeau, Elisabet, et al.
(författare)
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Effects of sulphur fertilization in organically cultivated faba bean
- 2020
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Ingår i: Agricultural and Food Science. - : Agricultural and Food Science. - 1459-6067 .- 1795-1895. ; 29, s. 471–481-
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Tidskriftsartikel (refereegranskat)abstract
- Optimal seed yield and quality requires that the sulphur (S) demand of faba bean (Vicia faba L.) is ensured. The ef-fect of S fertilization on organic cultivated faba bean was investigated under field conditions during two growing seasons (2017–2018), in Sweden. Kieserite (MgSO4) and gypsum (CaSO4) were applied at a rate of 20 and 40 kg ha-1to study the effect on faba bean growth, yield, crude protein (CP) content and amino acid (AA) composition. Gyp-sum and kieserite significantly increased S concentration of faba bean dry matter (DM) in 2017. The S concentra-tion ranged from 0.20% to 0.23% of DM compared to 0.18% in the untreated control. In 2018, kieserite application at 40 kg ha-1 significantly increased S concentration to 0.15% compared to 0.12% in the untreated control. The faba bean plants did, however, not respond neither with increased growth nor increased seed yield. The seed quality in terms of CP and S-containing AA, was not affected by S fertilization, however, significant differences were observed between the experimental sites.
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| 5. |
- Papoutsis, Konstantinos
(författare)
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Alternatives to DPA and ethoxyquin for preventing the development of superficial scald in apples: A review
- 2024
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Ingår i: Food Chemistry: X. - 2590-1575. ; 23
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Forskningsöversikt (refereegranskat)abstract
- Apples are one of most economically important crops worldwide with a production of approximately 96 million tons in 2022. During postharvest storage, apple quality can decline due to the development of physiological disorders. Superficial scald is one of the main physiological disorders that develops in apples during cold storage and results in quality deterioration. Superficial scald is controlled by synthetic antioxidants such as diphenylamine (DPA) and ethoxyquin. Both chemicals have been banned from the EU due to their toxicity. The current review provides an update on superficial scald complicated development mechanism and summarizes studies investigating postharvest treatments as alternatives to DPA and ethoxyquin. Ethylene and oxygen are important factors that trigger the development of superficial scald in apples by regulating various metabolic pathways during cold storage. More studies are required to investigate alternatives to synthetic antioxidants and elucidate the contribution level of the different metabolites to superficial scald development.
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| 6. |
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| 7. |
- Wiström, Björn
(författare)
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Artspecifika beskärningstider
- 2020
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Ingår i: Trädbladet. - 1400-514X. ; , s. 7-9
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 8. |
- Wiström, Björn, et al.
(författare)
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Intraspecific drought tolerance of Betula pendula genotypes: an evaluation using leaf turgor loss in a botanical collection
- 2021
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Ingår i: Trees - Structure and Function. - : Springer Science and Business Media LLC. - 0931-1890 .- 1432-2285. ; 35, s. 569-581
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Tidskriftsartikel (refereegranskat)abstract
- Key message The results showed a significant relationship between the potential evapotranspiration of the provenance collection site and the leaf turgor loss point and significant positive differences in drought tolerance between provenances and subspecies of B. pendula. The ecosystem services provided by urban trees make substantial contributions to the quality of urban living and securing resilience towards the challenges posed by a changing climate. Water deficits are a major abiotic stress for trees in urban environments and, in many regions, this stress is likely to be amplified under future climate scenarios. Although wide variation in drought tolerance exists at the species level, many species also show substantial intraspecific variation in drought tolerance. The aim of this study is to evaluate how drought tolerance, inferred from the water potential at leaf turgor loss point (psi(P0)), varies in Betula pendula from different geographical origins and determine if the observed drought tolerance can be related to the local climate and seasonal water balance from the provenance of origin, despite the trees now being established in similar soil and climatic conditions within a single botanical collection. Six subsp. betula, five subsp. mandshurica and two subsp. szechuanica were evaluated, giving a total of 12 different provenances. The results showed a significant relationship between the potential evapotranspiration of the provenance collection site and the leaf turgor loss point and significant positive differences in drought tolerance between provenances and subspecies of B. pendula. By directing efforts towards identifying more drought-tolerant genotypes, it will be possible to diversify the palette of trees that could confidently be integrated by urban tree planners and landscape architects into the urban landscape. The results of this study on different ecotypes of B. pendula clearly show that it is possible to find more drought-tolerant plant material.
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| 9. |
- Ruņǵis, Dainis, et al.
(författare)
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Genetic characterization of European potato onion (Allium cepavar Aggregatum G. Don) collections
- 2021
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Ingår i: Genetic Resources and Crop Evolution. - : Springer Science and Business Media LLC. - 0925-9864 .- 1573-5109. ; :68, s. 657-665
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Tidskriftsartikel (refereegranskat)abstract
- Potato onions (Allium cepa var aggregatum G. Don) are multiplying or aggregating onions, very similar to shallots and have been historically cultivated throughout Europe. Currently in Northern Europe they are maintained in home gardens and ex situ field collections. Potato onions are primarily vegetatively propagated, however in Estonia, near Lake Peipsi, this species has been propagated by seed since the seventeenth century. There is increasing interest in Northern Europe in utilizing this germplasm in organic and/or sustainable farming systems. The genetic diversity and relationship between and within European potato onion collections is unclear. From historical records it is known that cultivation, exchange and trade of potato onion has occurred throughout Europe for hundreds of years. This study utilised molecular markers to assess genetic diversity, duplication of genotypes and relationships among and between Nordic, Baltic, Czech and Croatian potato onion collections. Of 264 accessions, 80 catalogued as unique had identical genotypes with one or more other accessions, and are putative duplicates. The genetic diversity within two Estonian sexually propagated accessions was comparable to that found in all of the vegetatively propagated accessions. Accessions from the Nordic countries grouped together genetically, as did Latvian and Lithuanian accessions. Croatian accessions were genetically separated. These genetic relationships suggest historical movement of potato onion germplasm in North-Eastern Europe. The results, in conjunction with other passport and characterization data, can assist in the development of potato onion core collections, facilitating the conservation and utilization of valuable potato onion genetic resources.
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| 10. |
- Pelayo Lind, Olle, et al.
(författare)
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Biogas Digestate in Vegetable Hydroponic Production: pH Dynamics and pH Management by Controlled Nitrification
- 2021
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Ingår i: Waste and Biomass Valorization. - : Springer Science and Business Media LLC. - 1877-2641 .- 1877-265X. ; 12, s. 123-133
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Tidskriftsartikel (refereegranskat)abstract
- Soilless cultivation of vegetables with digestate fertilizer from biogas production as a nutrient source is a promising method for integrating food production and organic waste management. In this study, bok choy (Brassica rapa var. chinensis) was cultivated in a hydroponic nutrient film technique system with biogas digestate as the only fertilizer source. Nitrification in moving bed biofilm reactors (external and/or integrated into the hydroponic cultivation system) was employed to lower the high ammonium concentration in the digestate prior to use. Treatments with differing nitrification and digestate input strategies were compared with respect to pH dynamics, crop growth, shoot water content, and shoot mineral content. The results showed that < 20% longer cultivation time (< 1 week) gave similar yield in biogas digestate-based hydroponics as in conventional hydroponics based on synthetic fertilizers. Automatic pH control through addition of digestate resulted in similar shoot dry weight as in the mineral fertilizer reference system. It can be concluded that biogas digestate is a suitable plant nutrient source for hydroponic production of bok choy, considering productivity and circularity aspects. The combined impact of digestate ammonium content, digestate pH, and the nitrification step needs to be considered when designing a hydroponic system with biogas digestate as the fertilizer source. Graphic
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| 11. |
- Batte, Michael, et al.
(författare)
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Traits that define yield and genetic gain in East African highland banana breeding
- 2021
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Ingår i: Euphytica. - : Springer Science and Business Media LLC. - 0014-2336 .- 1573-5060. ; 217
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Tidskriftsartikel (refereegranskat)abstract
- East African highland bananas (Musa spp. AAA group) are an important staple in the Great Lakes region of East Africa. Their production has declined due to pests and diseases. Breeding for host plant resistance is a sustainable option for addressing this challenge. Understanding the relationships between growth parameters and bunch weight (i.e., yield) is crucial to guide breeding efforts for this crop. We investigated cause-effect relationships, through path analysis, in bunch weight of East African highland banana derived hybrids, their parents and grandparents. These family structures were planted in a 7 × 8 rectangular lattice design, replicated twice. Genetic gains for bunch weight (kg plant−1) and yield potential (t ha−1 year−1) were estimated. Significant increases of bunch weight and yield potential were noted from the landrace triploid germplasm, their derived primary tetraploid hybrids and secondary triploid bred-germplasm. Path analysis revealed that fruit length, circumference and number, number of hands and plant cycle number had a direct positive effect on the bunch weight. Days to fruit filling, days to maturity and index of non-spotted leaves had indirect effects on bunch weight. The average genetic gains for bunch weight and yield potential were 1.4% and 1.3% per year, respectively. This is the first report about genetic gains in banana breeding. Our findings may be useful for assessing progress and directing future breeding efforts in banana breeding.
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| 12. |
- Madalla, Noel, et al.
(författare)
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Farmers' preferences for East African highland cooking banana 'Matooke' hybrids and local cultivars
- 2023
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Ingår i: Agriculture & Food Security. - : Springer Science and Business Media LLC. - 2048-7010. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAn understanding of farmers' preferences of new banana cultivars and their characteristics is critical for developing and selecting cultivars that meet consumer needs. Therefore, phenotypic selection in a genetically variable population remains an important aspect of plant breeding.MethodsThe participatory varietal selection approach for preference ranking was used on 31 'Matooke' secondary and primary triploid hybrids and local banana cultivars evaluated between 2016 and 2019 in Uganda and Tanzania to investigate how farmers' preference attributes could help breeders identify superior cultivars. The quantitative data were analyzed using the Statistical Package for Social Sciences (SPSS). The qualitative data from farmers' focus group discussions (FGDs) were described using content analysis. The Mann–Whitney U test and Wilcoxon's signed-rank test were used to confirm the difference in farmers' preferences between groups.ResultsFarmers' approaches for defining characteristics were multivariate, and their preferences varied by site and country. Large fruit, a large bunch, market acceptability of the banana bunch, a sturdy stem, and an attractive appearance of the banana plant were the characteristics most preferred by farmers in Tanzania and Uganda. Tanzanian farmers preferred large bunches over other characteristics like bunch marketability and robust stem. Large fruit, drought tolerance, a strong stem, and phenotypic similarity to local cultivars were prioritized by Ugandan farmers. Both men and women farmers were more concerned with production-related characteristics, but the former valued marketing-related characteristics more, while the latter preferred use-related characteristics. Their preferences did not differ statistically, but the relative importance assigned by each group to the selected attributes was different.ConclusionFarmers' varietal preferences are frequently based on some assumed requirements, resulting in cultivar rejection or non-adoption. Therefore, determining the value attributed to each characteristic by various farmer groups is crucial in developing 'Matooke' banana cultivars with desired attributes that will boost the rate of adoption on-farms. Breeding initiatives that establish a system of integrated approaches and rely on thorough diagnosis of both production and consumption characteristics will best serve farmers' diverse preferences. To accomplish this, planning for varietal improvement initiatives at various levels—including internationally, regionally, nationally, and locally—would require a strong participatory structure that is gender inclusive.
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| 13. |
- Odilbekov, Firuz, et al.
(författare)
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QTL Mapping for resistance to early blight in a tetraploid potato population
- 2020
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Ingår i: Agronomy. - : MDPI AG. - 2073-4395. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Early blight of potato, caused by Alternaria solani, is an economically important foliar disease in most potato-growing regions. Growing cultivars with higher levels of resistance to early blight can reduce tuber yield losses and the need for fungicide applications. In this research, a bi-parental tetraploid potato population, segregating for resistance to early blight in leaves and tubers, was characterized to identify novel quantitative trait loci (QTL) associated with foliar and tuber early blight resistance. Assessment of the disease resistance in the foliage was performed by field evaluation and in tuber under controlled conditions. Results from this study revealed significant differences (P < 0.001) in resistance to A. solani among potato clones both in the leaves and in tubers. There was no statistically significant correlation (r = 0.06, P = 0.35) between the resistance scores from leaves and tubers. Several clones exhibited; however, high levels of resistance both in leaves and tubers and are; thus, promising candidates for breeding for early blight resistance. Linkage mapping revealed several QTL for early blight affecting both foliage and tubers. QTL associated with disease resistance in the tuber were found on chromosomes 1, 2, 3, 4, 8, 11 and 12. QTL associated with disease resistance in foliage were also examined for independence from defoliation, and independent QTL were; thus, found on chromosomes 5 and 11.
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| 14. |
- Ortiz Rios, Rodomiro Octavio
(författare)
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Anthocyanin-Rich Vegetables for Human Consumption—Focus on Potato, Sweetpotato and Tomato
- 2022
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 23
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Forskningsöversikt (refereegranskat)abstract
- Malnutrition, unhealthy diets, and lifestyle changes have become major risk factors for non-communicable diseases while adversely impacting economic growth and sustainable development. Anthocyanins, a group of flavonoids that are rich in fruits and vegetables, contribute positively to human health. This review focuses on genetic variation harnessed through crossbreeding and biotechnology-led approaches for developing anthocyanins-rich fruit and vegetable crops. Significant progress has been made in identifying genes involved in anthocyanin biosynthesis in various crops. Thus, the use of genetics has led to the development and release of anthocyanin-rich potato and sweet potato cultivars in Europe and the USA. The purple potato 'Kufri Neelkanth' has been released for cultivation in northern India. In Europe, the anthocyanin-rich tomato cultivar 'Sun Black' developed via the introgression of Aft and atv genes has been released. The development of anthocyanin-rich food crops without any significant yield penalty has been due to the use of genetic engineering involving specific transcription factors or gene editing. Anthocyanin-rich food ingredients have the potential of being more nutritious than those devoid of anthocyanins. The inclusion of anthocyanins as a target characteristic in breeding programs can ensure the development of cultivars to meet the nutritional needs for human consumption in the developing world.
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| 15. |
- Ortiz Rios, Rodomiro Octavio
(författare)
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Building Resilient and Robust Food Systems for a Hungry, Growing, and Changing World – Case Study of 2nd Topmost Ranked African Union and European Union Project at the West Africa Centre for Crop Improvement (WACCI)
- 2023
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Ingår i: ASRIC Journal on Agricultural Sciences. - 2795-3572 .- 2795-3564. ; 4, s. 167-188
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Tidskriftsartikel (refereegranskat)abstract
- The world’s population is projected to rise from 7.7 billion to 9.7 billion in 2050, with sub-Saharan Africa contributing half of this increase. A growing population signifies an increase in the demand placed on our food and limited natural resources. With the food demand expected to increase by 50% in the next 40 years, there is the urgency to make our food production systems more resilient and sustainable. The COVID-19 pandemic exposed the weak links in our current food systems: unsustainable; the trade-off between efficiency and resilience; highly centralized; increase in malnutrition and obesity; and income disparity. This paper discusses the impact of population growth on our environment, and the challenges in our food systems. We further expound on what the ideal food system is, and how we can transform our current food systems to make them more resilient and sustainable. Creating an ideal food system, able to meet our present and future needs requires sound partnerships between all actors of the food system. This is represented by a case study on the West Africa Centre for Crop Improvement (WACCI) human capacity development programmes geared towards the transformation of Africa’s food systems. The “human” aspect is a key element of food systems. In order to build resilient and sustainable food systems, it is critical for human resource to be equipped to learn, adapt, identify problems and implement changes as and when needed. As part of its core objectives, WACCI is dedicated to the capacity building and training of the next generation of scientists that would lead the transformation of the food system, especially in Africa. WACCI has trained so far 105 plant breeders from different countries in Africa and seeks to promote gender equality by advocating for more female scientists to be trained in the field. The role of gender in food security and sustainability cannot be undermined. WACCI is determined to contribute to food and nutrition security in Africa through human resource empowerment and partnerships that can create more resilient and sustainable food systems. Specifically, we highlighted in this article the outputs, outcomes and impact of an African Union – European Union project on “Crop and Soil Health improvement for sustainable agricultural intensification towards economic transformation in West Africa” which is the 2nd topmost ranked project in terms of results achieved in innovations, potential for scalability and impact.
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| 16. |
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| 17. |
- Ortiz Rios, Rodomiro Octavio
(författare)
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Foliar transcriptomes reveal candidate genes for late blight resistance in cultivars of diploid potato Solanum tuberosum L. Andigenum Group
- 2023
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Bok (refereegranskat)abstract
- Characterization of major resistance (R) genes to late blight (LB) –caused by the oomycete Phytophthora infestans– is very important for potato breeding. The objective of this study was to identify novel genes for resistance to LB from diploid Solanum tuberosum L. Andigenum Group (StAG) cultivar accessions. Using comparative analysis with a edgeR bioconductor package for differential expression analysis of transcriptomes, two of these accessions with contrasting levels of resistance to LB were analyzed using digital gene expression data. As a result, various differentially expressed genes (P ≤ 0.0001, Log2FC ≥ 2, FDR <0.001) were noted. The combination of transcriptomic analysis provided 303 candidate genes that are overexpressed and underexpressed, thereby giving high resistance to LB. The functional analysis showed differential expression of R genes and their corresponding proteins related to disease resistance, NBS-LRR domain proteins, and specific disease resistance proteins. Comparative analysis of specific tissue transcriptomes in resistant and susceptible genotypes can be used for rapidly identifying candidate R genes, thus adding novel genes from diploid StAG cultivar accessions for host plant resistance to P. infestans in potato.
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| 18. |
- Ortiz Rios, Rodomiro Octavio, et al.
(författare)
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Genetic gains in potato breeding as measured by field testing of cultivars released during the last 200 years in the Nordic Region of Europe
- 2022
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Ingår i: Journal of Agricultural Science. - 0021-8596 .- 1469-5146. ; 160, s. 310-316
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Tidskriftsartikel (refereegranskat)abstract
- Genetic gains (Delta(G)) are determined by the breeders' equation Delta(G) = [(ck sigma(2)(G))/(y sigma(P))], where c, k and y are the parental control, a function of the selection intensity and number of years to complete one selection cycle, respectively, while sigma(2)(G) and are sigma(P) the genetic variance and the square root of the phenotypic variance. Plant breeding programs should deliver above 1% of annual genetic gains after testing and selection. The aim of this research was to estimate genetic gains in potato breeding after testing of cultivars released in western Europe in the last 200 years under high yield potential, and stress-prone environments affected by a pest (late blight) or daylength. The annual genetic gains for tuber yield and flesh's starch content for potato breeding in Europe were about 0.3 and -0.1%, respectively, thus telling that the realized genetic gains of foreign cultivars for both traits are small or negative, respectively, in the Nordic testing sites. The national annual productivity gains in potato grown in Sweden were on average 0.7% in the last 60 years while the genetic gains for tuber yield considering only the table cultivars released after the 2nd World War were about 0.36%, thus showing that breeding contributed just above 1/2 of it. Furthermore, genetic gains for breeding low reducing sugars in the tuber flesh, and high host plant resistance to late blight were small (<0.2% per year). These results highlight that genetic gains are small when testing bred germplasm outside their target population of environments.
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| 19. |
- Ortiz Rios, Rodomiro Octavio, et al.
(författare)
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Genome-Based Genotype × Environment Prediction Enhances Potato (Solanum tuberosum L.) Improvement Using Pseudo-Diploid and Polysomic Tetraploid Modeling
- 2022
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Potato breeding must improve its efficiency by increasing the reliability of selection as well as identifying a promising germplasm for crossing. This study shows the prediction accuracy of genomic-estimated breeding values for several potato (Solanum tuberosum L.) breeding clones and the released cultivars that were evaluated at three locations in northern and southern Sweden for various traits. Three dosages of marker alleles [pseudo-diploid (A), additive tetrasomic polyploidy (B), and additive-non-additive tetrasomic polyploidy (C)] were considered in the genome-based prediction models, for single environments and multiple environments (accounting for the genotype-by-environment interaction or G × E), and for comparing two kernels, the conventional linear, Genomic Best Linear Unbiased Prediction (GBLUP) (GB), and the non-linear Gaussian kernel (GK), when used with the single-kernel genetic matrices of A, B, C, or when employing two-kernel genetic matrices in the model using the kernels from B and C for a single environment (models 1 and 2, respectively), and for multi-environments (models 3 and 4, respectively). Concerning the single site analyses, the trait with the highest prediction accuracy for all sites under A, B, C for model 1, model 2, and for GB and GK methods was tuber starch percentage. Another trait with relatively high prediction accuracy was the total tuber weight. Results show an increase in prediction accuracy of model 2 over model 1. Non-linear Gaussian kernel (GK) did not show any clear advantage over the linear kernel GBLUP (GB). Results from the multi-environments had prediction accuracy estimates (models 3 and 4) higher than those obtained from the single-environment analyses. Model 4 with GB was the best method in combination with the marker structure B for predicting most of the tuber traits. Most of the traits gave relatively high prediction accuracy under this combination of marker structure (A, B, C, and B-C), and methods GB and GK combined with the multi-environment with G × E model.
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| 20. |
- Ortiz Rios, Rodomiro Octavio
(författare)
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Genomic-led potato breeding for increasing genetic gains: achievements and outlook
- 2020
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Ingår i: Genetics, genomics and breeding of crop plants. - : Hapres. ; 2
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Forskningsöversikt (refereegranskat)abstract
- Potato is the third most important crop, after rice and wheat, in human diets worldwide. Genetic gains due to its crossbreeding for productivity per se appear to be stagnant in this tetraploid crop. Its genetic enhancement needs to overcome inherent barriers such as ploidy, outcrossing and heterozygosity. Pathogens and pests affect potato because they may infect the entire plant, including stems, leaves and tubers, thus leading to significant tuber yield loss. Hence, host plant resistance breeding remains key for improving the productivity of this crop. This article reviews recent research advances relevant to potato breeding emphasizing genomic resources, methods and tools for genetic analysis, mapping of genes and quantitative trait loci, and genomic prediction of breeding values (or genomic selection) for population improvement. In this regard, association genetics has provided insights onto genetic architecture and inheritance of priority breeding traits, as well as tagging them to DNA markers for their further use as aids for indirect selection. Early research results show the feasibility of genomic selection as a new breeding approach for a tetrasomic polyploid such as potato. This manuscript also highlights the proposed inbred line strategy for producing diploid F1 true potato seed hybrids, and how its use may speed up and increase genetic gains in potato breeding; as well as promoting alleles through gene editing. The paper ends proposing a new interploidy breeding approach considering ploidy manipulations and incorporating genomic selection and gene editing for both population improvement and cultivar development.
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| 21. |
- Ortiz Rios, Rodomiro Octavio, et al.
(författare)
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Genomic Prediction for Inbred and Hybrid Polysomic Tetraploid Potato Offspring
- 2024
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Ingår i: Agriculture. - 2077-0472. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Potato genetic improvement begins with crossing cultivars or breeding clones which often have complementary characteristics for producing heritable variation in segregating offspring, in which phenotypic selection is used thereafter across various vegetative generations (Ti ). The aim of this research was to determine whether tetrasomic genomic best linear unbiased predictors (GBLUPs) may facilitate selecting for tuber yield across early Ti within and across breeding sites in inbred (S1 ) and hybrid (F1 ) tetraploid potato offspring. This research used 858 breeding clones for a T1 trial at Umeå (Norrland, 63◦4903000 N 20◦1505000 E) in 2021, as well as 829 and 671 clones from the breeding population for T2 trials during 2022 at Umeå and Helgegården (Skåne, 56◦0104600 N 14◦0902400 E), respectively, along with their parents (S0 ) and check cultivars. The S1 and F1 were derived from selfing and crossing four S0 . The experimental layout was an augmented design of four-plant plots across testing sites, where breeding clones were non-replicated, and the parents and cultivars were placed in all blocks between the former. The genomic prediction abilities (r) for tuber weight per plant were 0.5944 and 0.6776 in T2 at Helgegården and Umeå, respectively, when T1 at Umeå was used as the training population. On average, r was larger in inbred than in hybrid offspring at both breeding sites. The r was also estimated using multi-environment data (involving at least one S1 and one F1 ) for T2 performance at both breeding sites. The r was strongly influenced by the genotype in both S1 and F1 offspring irrespective of the breeding site.
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| 22. |
- Ortiz Rios, Rodomiro Octavio, et al.
(författare)
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Heritable Variation, Genetic and Phenotypic Correlations for Tuber Traits and Host Plant Resistance to Late Blight for Potato Breeding in Scandinavian Testing Sites
- 2021
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Ingår i: Agriculture. - : MDPI AG. - 2077-0472. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Potato breeding aims to improve crop productivity, quality and resilience based on heritablecharacteristics. Estimating the trait heritability and correlations—both genetic and phenotypic—amongcharacteristics in a target population of environments allows us to define the best breeding methodthat leads to selection gains. Breeding clones (47) and released cultivars (209) were grown usingsimple lattice designs at three testing sites in northern and southern Sweden to estimate the bestlinear unbiased predictors (BLUPs) derived from mixed linear models for characteristics such as tuberweight (total and according to sizes), host plant resistance to late blight (caused by the oomycetePhytophthora infestans) and tuber quality (starch percentage based on specific gravity measurementsand reducing sugars). There was significant heritable variation for all the characteristics investigated.Tuber starch percentage and total tuber weight were the traits with the highest broad-sense heritability(H2), while the weight for the smallest size (<40 mm) had the highest H2 among the different tubercategories. These results show the potential for further improving these traits for Scandinavia throughrecombination and selection in segregating offspring. The genetic and phenotypic correlations amongthe tuber weight characteristics were significant (p 0.05) irrespective of their sizes, but none weresignificant (p > 0.05) with tuber starch percentage. Host plant resistance to late blight was negativelyand significantly associated with tuber weight and starch percentage, thereby showing the strongeffects of this disease on the productivity and quality of the potatoes.
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| 23. |
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| 24. |
- Ortiz Rios, Rodomiro Octavio
(författare)
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Nutrient-dense orange-fleshed sweetpotato: advances in drought-tolerance breeding and understanding of management practices for sustainable next-generation cropping systems in sub-Saharan Africa
- 2020
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Ingår i: Frontiers in sustainable food systems. - : Frontiers Media SA. - 2571-581X. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Almost half of children <5 years old living in sub-Saharan Africa (SSA) suffer from vitamin A deficiency and 60% suffer from iron deficiency. Thus, there has been a strong commitment to breeding for, promoting awareness of, and delivering adapted pro-vitamin A rich orange-fleshed sweetpotato (OFSP) in SSA during the past two decades and for enhanced iron content since 2014. This review article focuses on major breeding efforts in SSA to enhance the drought tolerance of OFSP and reviews integrated crop management practices for improved and sustained sweetpotato production in SSA farming systems. Under climate change, the frequency and severity of droughts is expected to increase. Technical issues are presented in the context of addressing challenges along the entire value chain to ensure adoption. First, the use of an accelerated breeding scheme reduced the breeding cycle from 8–10 to 4–5 years. Since 2010, 19 drought-tolerant OFSP cultivars have been released in Mozambique, 7 in Malawi, and 2 in South Africa. Moreover, research in four breeding populations using the heterosis exploiting breeding scheme (HEBS) demonstrated that within one breeding cycle of 5 years, clones with significantly higher root yield, abiotic tolerance, host plant resistance to pests and diseases, and early maturity can be produced. In the future, HEBS will be combined with greater use of modern genomic tools, new phenotyping tools, and CRISPR/Cas9-mediated gene editing. Second, beyond genetic enhancements, evidence is presented that using improved crop management systems, existing sweetpotato yields can be increased 2–4 times. Current knowledge is reviewed concerning sweetpotato's role in diverse farming systems, but integrated crop management is clearly under researched. Third, the outlook for drought tolerance breeding indicates that two distinct classes of nutrient-rich cultivars are emerging: (1) Early maturing cultivars (<4 month growing period) that escape drought but also serve humid environments with small landholding size per capita; and (2) Medium maturing (4–6 month growing period) cultivars that avoid drought, are drought tolerant and exhibit continuous root formation. Increasing commercialization of the crop and climate change will drive demand, and the willingness of farmers to invest in improved sweetpotato crop management.
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| 25. |
- Ortiz Rios, Rodomiro Octavio, et al.
(författare)
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Partial least squares enhance multi-trait genomic prediction of potato cultivars in new environments
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- It is of paramount importance in plant breeding to have methods dealing with large numbers of predictor variables and few sample observations, as well as efficient methods for dealing with high correlation in predictors and measured traits. This paper explores in terms of prediction performance the partial least squares (PLS) method under single-trait (ST) and multi-trait (MT) prediction of potato traits. The first prediction was for tested lines in tested environments under a five-fold cross-validation (5FCV) strategy and the second prediction was for tested lines in untested environments (herein denoted as leave one environment out cross validation, LOEO). There was a good performance in terms of predictions (with accuracy mostly > 0.5 for Pearson’s correlation) the accuracy of 5FCV was better than LOEO. Hence, we have empirical evidence that the ST and MT PLS framework is a very valuable tool for prediction in the context of potato breeding data.
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