Key message
Cooked bean flavor and texture vary within and across 20 Andean seed types; SNPs are significantly associated with total flavor, beany, earthy, starchy, bitter, seed-coat perception, and ...cotyledon texture.
Common dry beans are a nutritious food recognized as a staple globally, but their consumption is low in the USA. Improving bean flavor and texture through breeding has the potential to improve consumer acceptance and suitability for new end-use products. Little is known about genetic variability and inheritance of bean sensory characteristics. A total of 430 genotypes of the Andean Diversity Panel representing twenty seed types were grown in three locations, and cooked seeds were evaluated by a trained sensory panel for flavor and texture attribute intensities, including total flavor, beany, vegetative, earthy, starchy, sweet, bitter, seed-coat perception, and cotyledon texture. Extensive variation in sensory attributes was found across and within seed types. A set of genotypes was identified that exhibit extreme attribute intensities generally stable across all three environments. seed-coat perception and total flavor intensity had the highest broad-sense heritability (0.39 and 0.38, respectively), while earthy and vegetative intensities exhibited the lowest (0.14 and 0.15, respectively). Starchy and sweet flavors were positively correlated and highest in white bean genotypes according to principal component analysis. SNPs associated with total flavor intensity (six SNPs across three chromosomes), beany (five SNPs across four chromosomes), earthy (three SNPs across two chromosomes), starchy (one SNP), bitter (one SNP), seed-coat perception (three SNPs across two chromosomes), and cotyledon texture (two SNPs across two chromosomes) were detected. These findings lay a foundation for incorporating flavor and texture in breeding programs for the development of new varieties that entice growers, consumers, and product developers alike.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Anthracnose is a seed-borne disease of common bean (Phaseolus vulgaris L.) caused by the fungus Colletotrichum lindemuthianum, and the pathogen is cosmopolitan in distribution. The objectives of this ...study were to identify new sources of anthracnose resistance in a diverse panel of 230 Andean beans comprised of multiple seed types and market classes from the Americas, Africa, and Europe, and explore the genetic basis of this resistance using genome-wide association mapping analysis (GWAS). Twenty-eight of the 230 lines tested were resistant to six out of the eight races screened, but only one cultivar Uyole98 was resistant to all eight races (7, 39, 55, 65, 73, 109, 2047, and 3481) included in the study. Outputs from the GWAS indicated major quantitative trait loci (QTL) for resistance on chromosomes, Pv01, Pv02, and Pv04 and two minor QTL on Pv10 and Pv11. Candidate genes associated with the significant SNPs were detected on all five chromosomes. An independent QTL study was conducted to confirm the physical location of the Co-1 locus identified on Pv01 in an F4:6 recombinant inbred line (RIL) population. Resistance was determined to be conditioned by the single dominant gene Co-1 that mapped between 50.16 and 50.30 Mb on Pv01, and an InDel marker (NDSU_IND_1_50.2219) tightly linked to the gene was developed. The information reported will provide breeders with new and diverse sources of resistance and genomic regions to target in the development of anthracnose resistance in Andean beans.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Anthracnose caused by Colletotrichum lindemuthianum is a major disease of common bean (Phaseolus vulgaris) worldwide. Yellow beans are a major market class of common bean especially in eastern and ...southern Africa. The Yellow Bean Collection (YBC), which is comprised of 255 genotypes, and has not been used previously in genetic studies on anthracnose, is an excellent genetic resource for understanding the extent of anthracnose resistance and its genetic architecture in the yellow bean market class. The objectives of this study were i) evaluate the YBC for resistance to races 5, 19, 39, 51, 81, 183, 1050 and 1105 of C. lindemuthianum. and ii) conduct genome-wide association analysis to identify genomic regions and candidate genes associated with resistance to C. lindemuthianum. The YBC was genotyped with 72,866 SNPs, and genome-wide association analysis was conducted using Mixed Linear Model in TASSEL. Andean and Middle American genotypes with superior levels of resistance to the eight races were identified. YBC278 was the only one among 255 genotypes that was highly resistant to all eight races. Resistance to anthracnose in the YBC was controlled by major-effect loci on chromosomes Pv01, Pv03, Pv04, Pv05 and Pv07. The genomic region on Pv01, which overlapped with the Andean locus Co-1 provided resistance to races 81, 1050 and 1105. Significant SNPs for resistance to race 39 were identified on Pv02. The genomic region on Pv04, which overlapped with known major-effect loci Co-3, Co-15, Co-16, Co-y and Co-z, provided resistance to races 5, 19, 51 and 183. Novel genomic regions for resistance to race 39 were identified on Pv05 and Pv07. Plant resistance genes (R genes) with NB-ARC and LRR domains, which occurred in clusters, were identified as positional candidate genes for genomic regions on Pv02 and Pv04.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Bean (Phaseolus vulgaris) anthracnose caused by the hemi-biotrophic pathogen Colletotrichum lindemuthianum is a major factor limiting production worldwide. Although sources of resistance have been ...identified and characterized, the early molecular events in the host-pathogen interface have not been investigated. In the current study, we conducted a comprehensive transcriptome analysis using Illumina sequencing of two near isogenic lines (NILs) differing for the presence of the Co-1 gene on chromosome Pv01 during a time course following infection with race 73 of C. lindemuthianum. From this, we identified 3,250 significantly differentially expressed genes (DEGs) within and between the NILs over the time course of infection. During the biotrophic phase the majority of DEGs were up regulated in the susceptible NIL, whereas more DEGs were up-regulated in the resistant NIL during the necrotrophic phase. Various defense related genes, such as those encoding PR proteins, peroxidases, lipoxygenases were up regulated in the resistant NIL. Conversely, genes encoding sugar transporters were up-regulated in the susceptible NIL during the later stages of infection. Additionally, numerous transcription factors (TFs) and candidate genes within the vicinity of the Co-1 locus were differentially expressed, suggesting a global reprogramming of gene expression in and around the Co-1 locus. Through this analysis, we reduced the previous number of candidate genes reported at the Co-1 locus from eight to three. These results suggest the dynamic nature of P. vulgaris-C. lindemuthianum interaction at the transcriptomic level and reflect the role of both pathogen and effector triggered immunity on changes in plant gene expression.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A genome‐wide association study (GWAS) using a global Andean diversity panel (ADP) of 237 genotypes of common bean (Phaseolus vulgaris L.) was conducted to gain insight into the genetic architecture ...of phenology, biomass, yield components, and seed yield traits. The panel was evaluated for 2 yr in field trials in Michigan and genotyped with 5398 single nucleotide polymorphism (SNP) markers. After correcting for population structure and cryptic relatedness, significant SNP markers associated with several agronomic traits were identified. Positional candidate genes, including Phvul.001G221100 on P. vulgaris (Pv) chromosome 01, associated with days to flowering and maturity were identified. Significant SNPs for seed yield were identified on Pv03 and Pv09 and colocalized with quantitative trait loci (QTL) for yield from previous studies conducted in several environments and contrasting genetic backgrounds. The majority of germplasm carrying the alleles with positive effects on seed yield was of African origin and largely underutilized in US breeding programs. The study provided insights into the genetic architecture of agronomic traits in Andean beans.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Heat stress is an abiotic factor that reduces wheat yields. This study assessed the morphological and physiological traits essential for early detection of heat tolerance in wheat and identified ...suitable genotypes for specific agro-ecologies prone to heat stress in Zambia. Twelve wheat genotypes were evaluated in a heat-stress environment (Chakanka) and a non-stress heat environment (UNZA). Early heat stress indicators like leaf thickness and chlorophyll content had a 92% and 90% relationship with the yields of heat-tolerant genotypes, respectively. An increase in either or both parameters improved the yields of heat-tolerant genotypes relative to the susceptible ones. Among the heat-tolerant genotypes, Entry 48 had the highest yield (5866.5 kg ha−1) at the heat-stress site; this yield was 51.2% higher than that of the most susceptible genotype, Kwale (2864.0 kg ha−1). Entry 48 was more adapted to heat stress and yielded better than others due to early flowering (53.8 days to 50% flowering) and longer grain-filling duration (40.3 days). Entry 48 possessed traits of a climate-smart variety and could be a candidate for breeding future heat-tolerant and high-yielding wheat varieties.
The importance of legumes in sustainable cropping systems has been studied extensively. Among legumes, common beans (Phaseolus vulgaris L.) are a rich world resource of biodiversity with two centers ...of domestication (Andes and Central America) and over 10 major market classes cultivated globally. Common beans are recognized as a nutrient‐dense, healthy food source due to their high protein, dietary fiber, and minerals content and also being a rich source of resistant and slowly digestible starch, which elicits a lower glycemic response. Some bioactive compounds present in beans are reported to mitigate cardiovascular diseases, hypertension, hyper‐cholesterolemia, and cancer. Dry bean production systems provide unique advantages that support sustainability, including a low carbon footprint and short growth cycle, which facilitates crop diversification and cover crop integration. Symbiotic nitrogen fixation (SNF), a unique characteristic of legumes, promotes environmentally friendly production through modest fertilizer use. Advances to improve the upright plant architecture of beans during the last two decades have enhanced options for direct harvest thereby reducing the number of equipment passes required. Overall, the sustainability implications of diversifying crop rotation using beans result in reduced requirements for environmentally unfriendly inputs and buffering of crop productivity under variable weather conditions. This review article covers common beans' role in agricultural sustainability (biodiversity, SNF, rotational diversity, harvest management) and as a sustainable source of nutrition and food security. Further discussion includes measures to enhance dry beans sustainability through breeding and crop management practices by addressing biotic and abiotic stresses (diseases, drought, high temperature, waterlogging, conservation tillage).
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Common bean (Phaseolus vulgaris L.) fixes atmospheric nitrogen (N2) through symbiotic nitrogen fixation (SNF) at levels lower than other grain legume crops. An understanding of the genes and ...molecular mechanisms underlying SNF will enable more effective strategies for the genetic improvement of SNF traits in common bean. In this study, transcriptome profiling was used to identify genes and molecular mechanisms underlying SNF differences between two common bean recombinant inbred lines that differed in their N-fixing abilities. Differential gene expression and functional enrichment analyses were performed on leaves, nodules and roots of the two lines when grown under N-fixing and non-fixing conditions. Receptor kinases, transmembrane transporters, and transcription factors were among the differentially expressed genes identified under N-fixing conditions, but not under non-fixing conditions. Genes up-regulated in the stronger nitrogen fixer, SA36, included those involved in molecular functions such as purine nucleoside binding, oxidoreductase and transmembrane receptor activities in nodules, and transport activity in roots. Transcription factors identified in this study are candidates for future work aimed at understanding the functional role of these genes in SNF. Information generated in this study will support the development of gene-based markers to accelerate genetic improvement of SNF in common bean.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Genome-wide association studies (GWAS) have been utilized to detect genetic variations related to several agronomic traits and disease resistance in common bean. However, its application in the ...powdery mildew (PM) disease to identify candidate genes and their location in the common bean genome has not been fully addressed. Single-nucleotide polymorphism (SNP) genotyping with a BeadChip containing 5398 SNPs was used to detect genetic variations related to PM disease resistance in a panel of 211 genotypes grown under two field conditions for two consecutive years. Significant SNPs identified on chromosomes Pv04 and Pv10 were repeatable, ensuring the phenotypic data’s reliability and the causal relationship. A cluster of resistance genes was revealed on the Pv04 of the common bean genome, coiled-coil-nucleotide-binding site–leucine-rich repeat (CC-NBS-LRR, CNL), and Toll/interleukin-1 receptor-nucleotide-binding site–leucine-rich repeat type (TIR-NBS-LRR, TNL)-like resistance genes were identified. Furthermore, two resistance genes,
Phavu_010G1320001g
and
Phavu_010G136800g
, were also identified on Pv10. Further sequence analysis showed that these genes were homologs to the disease-resistance protein (RLM1A-like) and the putative disease-resistance protein (
At4g11170.1
) in
Arabidopsis
. Significant SNPs related to two LRR receptor-like kinases (RLK) were only identified on Pv11 in 2018. Many genes encoding the auxin-responsive protein, TIFY10A protein, growth-regulating factor five-like, ubiquitin-like protein, and cell wall RBR3-like protein related to PM disease resistance were identified nearby significant SNPs. These results suggested that the resistance to PM pathogen involves a network of many genes constitutively co-expressed.