Common Bean Accessions Research Articles

Using phenomics to identify and integrate traits of interest for better-performing common beans: A validation study on an interspecific hybrid and its Acutifolii parents.

Evaluations of interspecific hybrids are limited, as classical genebank accession descriptors are semi-subjective, have qualitative traits and show complications when evaluating intermediate accessions. However, descriptors can be quantified using recognized phenomic traits. This digitalization can identify phenomic traits which correspond to the percentage of parental descriptors remaining expressed/visible/measurable in the particular interspecific hybrid. In this study, a line of P. vulgaris, P. acutifolius and P. parvifolius accessions and their crosses were sown in the mesh house according to CIAT seed regeneration procedures. Three accessions and one derived breeding line originating from their interspecific crosses were characterized and classified by selected phenomic descriptors using multivariate and machine learning techniques. The phenomic proportions of the interspecific hybrid (line INB 47) with respect to its three parent accessions were determined using a random forest and a respective confusion matrix. The seed and pod morphometric traits, physiological behavior and yield performance were evaluated. In the classification of the accession, the phenomic descriptors with highest prediction force were Fm', Fo', Fs', LTD, Chl, seed area, seed height, seed Major, seed MinFeret, seed Minor, pod AR, pod Feret, pod round, pod solidity, pod area, pod major, pod seed weight and pod weight. Physiological traits measured in the interspecific hybrid present 2.2% similarity with the P. acutifolius and 1% with the P. parvifolius accessions. In addition, in seed morphometric characteristics, the hybrid showed 4.5% similarity with the P. acutifolius accession. Here we were able to determine the phenomic proportions of individual parents in their interspecific hybrid accession. After some careful generalization the methodology can be used to: i) verify trait-of-interest transfer from P. acutifolius and P. parvifolius accessions into their hybrids; ii) confirm selected traits as "phenomic markers" which would allow conserving desired physiological traits of exotic parental accessions, without losing key seed characteristics from elite common bean accessions; and iii) propose a quantitative tool that helps genebank curators and breeders to make better-informed decisions based on quantitative analysis.

Physico-chemical and Nutritional Characterization of Phaseolus vulgaris L. Germplasm

Background: Beans constitute one of the most important grain legume species from the socioeconomic point of view, playing an essential role in a sustainable agriculture and food safety and nutrition. In fact, beans contain a rich diversity in nutrients, highlighting their high protein, starch and fiber content. Canary Islands have a considerable diversity of beans, including three of the five cultivated species of Phaseolus: P. coccineus, P. lunatus and P. vulgaris, the latter being the most cultivated. Methods: Proximate composition, total phenolics, pH, acidity, minerals and trace elements were determined in 23 common bean accessions (P. vulgaris) in order to find out their nutritional potential and promote their cultivation. Result: Parameters found fell well into the ranges of the data described in the literature for beans. The consumption of beans contributes remarkedly to the daily intake of protein (although is deficient in sulfur amino-acids), fiber, phenolic compounds, minerals such as Mg and K and trace elements as Fe (although with low bioavailability), Cu and Mn. Phenolic compounds in beans increases when pH decreased and acidity increased. Protein content was positively correlated with trace elements content, except Se. Color of the seed influenced on content protein, starch, fiber, P, K, Mg, Fe, Cu and Zn, while shape only affected on starch, fiber, P and K.

Heat Stress Tolerance: A Prerequisite for the Selection of Drought- and Low Phosphorus-Tolerant Common Beans for Equatorial Tropical Regions Such as Ghana

Forty common bean accessions of multiple genetic background trait attribution regarding drought tolerance were selected based on mean yield performance from an earlier field test evaluation conducted using augmented RCBD. The various bean genotypes were further evaluated with phosphorus and water treatment interactions at two different levels for each factor. The experiment was conducted in a 2 × 2 × 40 factorial using RCBD with three replications under screen-house conditions at the CSIR-Crops Research Institute, Kumasi-Ghana. The objective was to select drought- and low phosphorus-tolerant common bean genotypes; which are suitable for tropical climatic conditions. The results showed that common bean with drought and heat trait tolerance survived, developed flowers and podded with seeds to physiological maturity, whilst genotypes with no heat trait tolerance had impaired reproductive structural development and growth disruption; thus, flowers could not develop into pods with seeds. This reproductive developmental anomaly was due to prevailing average daytime and nighttime high temperatures of 35.45 °C and 29.95 °C, respectively, recorded during the growth period, which reduced pollen fertility. Among the 478 experimental bean plants (two plants were missing) analyzed, 141 (29.5%) did not flower, 168 (35.18%) had their pods dropped whilst 99 (20.7%) podded with seeds to achieve physiological maturity. The podded-seed bean genotypes were of the SEF-line pedigrees, which were shown to be heat and drought-tolerant. Meanwhile, bean accessions with SMC, SMN and SMR code prefixes did not pod into seed despite possessing drought-tolerant traits. The effects of interactions between phosphorus and water treatments on the root characteristics of drought-tolerant common bean were as follows: root length, root surface area, average root diameter and root volume growth extensions doubled dimensionally under optimum conditions (P2W2) compared to stressed conditions (P1W1). The results from the present study identified four SEF-bean genotypes, namely, SEF15, SEF 47, SEF 60 and SEF 62, as superior yield performers, even under low soil phosphorus and in extreme high temperature conditions. Therefore, breeding for the selection of drought- and low-P-tolerant common bean for tropical agro-ecological environments must also consider concomitant heat stress tolerance.

Evaluation of common bean (Phaseolus vulgaris) genotypes for resistance to common bacterial blight and angular leaf spot diseases, and agronomic performances

Common bean is the most important pulse crops worldwide and in Ethiopia for its multipurpose uses. However, common bean production and productivity is mainly constrained by common bacterial blight (CBB) and angular leaf spot (ALS) diseases. Identifying and using resistant common bean genotypes is the best option to reduce the impact of such bacterial and fungal diseases. Field experiments were carried out to evaluate the genetic resistance of 25 common bean genotypes as treatments to CBB and ALS diseases, and agronomic performances at Haramaya and Melkassa, Ethiopia, during the 2019 and 2020 main cropping seasons. The treatments were arranged in a 5 × 5 triple lattice design with three replications. Data on disease intensity, growth, grain yield and yield components were recorded. Analysis of variance indicated significant (p < 0.0001) variations existed among the genotypes for diseases intensity, grain yield and yield components. Eight genotypes, namely DAB-388, DAB-478, DRKDDRB-70, DRKDDRB-81, NUA-225, NUA-517, NUA-536 and NUA-577 attained relatively low disease severity, AUDPC and disease progress rate next to the checks Zoasho (DAB-96) and Gorossa (Biofort large seed-5) to both common bean diseases regardless of locations and seasons. The genotype DAB-525 showed a moderately resistant reaction to both CBB and ALS, and the other genotypes demonstrated variable disease resistance reactions at both locations and in the two cropping years. Similarly, genotypes DAB-388, NUA-225, NUA-517, and NUA-577 relatively executed well for grain yield and yield components at both experimental fields in the 2019 and 2020 main cropping seasons. Disease severity and grain yield variably and negatively associated with reaction groups of genotypes evaluated for reaction CBB and ALS diseases. In the study, resistance to CBB and ALS diseases and good agronomic performing common bean genotypes were identified which could be important for smallholder and commercial bean production in the study area and other similar agro-ecologies in Ethiopia. It is suggested that a large number of common bean accessions should be evaluated in CBB and ALS hot spot agro-ecologies of Ethiopia for more sources of resistance and better agronomic advantages.

Magnesium- a Forgotten Element: Phenotypic Variation and Genome Wide Association Study in Turkish Common Bean Germplasm.

Magnesium (Mg) is the fourth most abundant element in the human body and plays the role of cofactor for more than 300 enzymatic reactions. In plants, Mg is involved in various key physiological and biochemical processes like growth, development, photophosphorylation, chlorophyll formation, protein synthesis, and resistance to biotic and abiotic stresses. Keeping in view the importance of this element, the present investigation aimed to explore the Mg contents diversity in the seeds of Turkish common bean germplasm and to identify the genomic regions associated with this element. A total of 183 common bean accessions collected from 19 provinces of Turkey were used as plant material. Field experiments were conducted according to an augmented block design during 2018 in two provinces of Turkey, and six commercial cultivars were used as a control group. Analysis of variance depicted that Mg concentration among common bean accessions was statistically significant (p < 0.05) within each environment, however genotype × environment interaction was non-significant. A moderate level (0.60) of heritability was found in this study. Overall mean Mg contents for both environments varied from 0.33 for Nigde-Dermasyon to 1.52 mg kg−1 for Nigde-Derinkuyu landraces, while gross mean Mg contents were 0.92 mg kg−1. At the province level, landraces from Bolu were rich while the landraces from Bitlis were poor in seed Mg contents respectively. The cluster constellation plot divided the studied germplasm into two populations on the basis of their Mg contents. Marker-trait association was performed using a mixed linear model (Q + K) with a total of 7,900 DArTseq markers. A total of six markers present on various chromosomes (two at Pv01, and one marker at each chromosome i.e., Pv03, Pv07, Pv08, Pv11) showed statistically significant association for seed Mg contents. Among these identified markers, the DArT-3367607 marker present on chromosome Pv03 contributed to maximum phenotypic variation (7.5%). Additionally, this marker was found within a narrow region of previously reported markers. We are confident that the results of this study will contribute significantly to start common bean breeding activities using marker assisted selection regarding improved Mg contents.

Genetic diversity and marker trait association for yield attributing traits in accessions of common bean (Phaseolus vulgarisL.) in India

AbstractCommon bean (Phaseolus vulgarisL.) is a highly economically important crop worldwide and a particularly important source of protein and minerals for people in less developed countries. Improving yield is a vital objective to meet the increasing demand for food due to the expanding human population. The present study was undertaken to study the genetic architecture of agronomic traits of common bean in India, particularly in the north-western Himalayan region. Marker-trait association (MTA) analysis was performed in a population of 100 common bean accessions using polymorphic microsatellite markers.Population structure analysis based on SSR markers divided the accessions into three main subpopulations. Ten significant MTAs were found using general linear model (GLM) and mixed linear model (MLM) approaches. We found two markers i.e. BM142 and J04555 associated with 100 seed weight and pods per plant common in both the GLM and MLM approach markers. All the MTAs were considered as major MTAs contributing more than 25% phenotypic variation. The significant quantitative trait loci identified in this study could be used in marker-assisted breeding to accelerate the genetic improvement of yield and development of high yielding common beans lines.

Analysis of genetic diversity among common bean germplasm by start codon targeted (SCoT) markers.

Breeding strategies to improve modern varieties having high yield, high nutritional value and resistance to biotic and abiotic stress, etc. is very important to make up for the food deficiencies. Molecular studies as a tool in breeding programs for the characterization of germplasm have been performed with several DNA marker systems. In the present study, the genetic diversity of 53 common bean landraces and 22 registered varieties from Turkey, and 12 genotypes from USDA was investigated using start codon targeted (SCoT) markers for the first time worldwide. The 8 primers having stronger and more polymorphic bands were used for PCR amplification. The mean polymorphic band of all primers was found as 13.13. The average of polymorphic information content and resolving power values was 0.34 and 7.55, respectively. Analysis of molecular variance (AMOVA) explored the existence of higher genetic diversity within populations accounting for 92% compared to among populations variations. According to cluster analysis (UPGMA) and genetic structure based on SCoT data, accessions were separated into Andean (PopA) and Mesoamerican PopB) gene pools. Moreover, accessions were mostly placed in the same groups/subgroups according to their geographical origin. A high level of genetic diversity was observed between the investigated accessions in this work. The findings will help to plant breeders to characterize common bean accessions.

Genome-wide association studies dissect the genetic architecture of seed shape and size in common bean.

Seed weight and size are important yield components. Thus, selecting for large seeds has been a key objective in crop domestication and breeding. In common bean, seed shape is also important since it influences industrial processing and plays a vital role in determining the choices of consumers and farmers. In this study, we performed genome-wide association studies on a core collection of common bean accessions to dissect the genetic architecture and identify genomic regions associated with seed morphological traits related to weight, size, and shape. Phenotypic data were collected by high-throughput image-based approaches, and utilized to test associations with 10,362 single-nucleotide polymorphism markers using multilocus mixed models. We searched within genome-associated regions for candidate genes putatively involved in seed phenotypic variation. The collection exhibited high variability for the entire set of seed traits, and the Andean gene pool was found to produce larger, heavier seeds than the Mesoamerican gene pool. Strong pairwise correlations were verified for most seed traits. Genome-wide association studies identified marker–trait associations accounting for a considerable amount of phenotypic variation in length, width, projected area, perimeter, and circularity in 4 distinct genomic regions. Promising candidate genes were identified, e.g. those encoding an AT-hook motif nuclear-localized protein 8, type 2C protein phosphatases, and a protein Mei2-like 4 isoform, known to be associated with seed size and weight regulation. Moreover, the genes that were pinpointed are also good candidates for functional analysis to validate their influence on seed shape and size in common bean and other related crops.

Portuguese Common Bean Natural Variation Helps to Clarify the Genetic Architecture of the Legume's Nutritional Composition and Protein Quality.

Common bean is a nutritious food legume widely appreciated by consumers worldwide. It is a staple food in Latin America, and a component of the Mediterranean diet, being an affordable source of protein with high potential as a gourmet food. Breeding for nutritional quality, including both macro and micronutrients, and meeting organoleptic consumers’ preferences is a difficult task which is facilitated by uncovering the genetic basis of related traits. This study explored the diversity of 106 Portuguese common bean accessions, under two contrasting environments, to gain insight into the genetic basis of nutritional composition (ash, carbohydrates, fat, fiber, moisture, protein, and resistant starch contents) and protein quality (amino acid contents and trypsin inhibitor activity) traits through a genome-wide association study. Single-nucleotide polymorphism-trait associations were tested using linear mixed models accounting for the accessions’ genetic relatedness. Mapping resolution to the gene level was achieved in 56% of the cases, with 102 candidate genes proposed for 136 genomic regions associated with trait variation. Only one marker-trait association was stable across environments, highlighting the associations’ environment-specific nature and the importance of genotype × environment interaction for crops’ local adaptation and quality. This study provides novel information to better understand the molecular mechanisms regulating the nutritional quality in common bean and promising molecular tools to aid future breeding efforts to answer consumers’ concerns.

Characterization of Colletotrichum lindemuthianum Races in Zambia and Evaluation of the CIAT Phaseolus Core Collection for Resistance to Anthracnose.

Colletotrichum lindemuthianum, the causal pathogen of common bean (Phaseolus vulgaris) anthracnose, is highly variable. Therefore, understanding its race structure and identification of new sources of resistance is necessary for the development of varieties with durable resistance. The objectives of this study were (i) to characterize isolates of C. lindemuthianum collected from three major bean-growing regions in Zambia and (ii) evaluate the International Center for Tropical Agriculture (CIAT) Phaseolus core collection for resistance to C. lindemuthianum races 37, 73, and 566 and a blend of 20 races. Isolates collected from three major bean-growing districts in Zambia, namely Mporokoso, Mpika, and Mbala, were characterized as races 37, 73, and 566, respectively. A subset of the CIAT core collection comprising 885 accessions of common bean, 13 accessions of scarlet runner bean (Phaseolus coccineus), and 11 accessions of year bean (Phaseolus dumosus) was evaluated for resistance to races 37, 73, and 566 and a blend of 20 races in a greenhouse at the University of Zambia, Lusaka, Zambia. Totals of 72, 66, 48, and 9% of P. vulgaris accessions evaluated were highly resistant to races 37, 73, and 566 and a blend of 20 races, respectively. Also, accessions of P. coccineus and P. dumosus highly resistant to races 37, 73, and 566 were identified. Only eight of the 331 P. vulgaris accessions were highly resistant to all three individual races (37, 73, and 566) and to a blend of 20 races. These eight accessions constitute a valuable breeding resource for developing varieties with durable resistance to C. lindemuthianum.

Population structure and genetic diversity in common bean accessions from Northeast Brazil

Common bean is of great relevance for several countries, especially those located in tropical regions. Common bean in Brazil has a wide genetic diversity, which is used by breeders to improve this crop. In this study, we used GBS methodology to genotype common bean accessions from Northeast Brazil, and to study its population structure and genetic diversity. After a filtering process, we identified 30,529 high-quality SNPs distributed in 11 linkage groups. The number of SNPs per chromosome ranged from 1,731 to 3,853. The population structure analysis separated the accessions into two subpopulations, according to K=2, one subpopulation with 26 Andean and the other with 60 Middle American accessions. Considering K=3, Middle American accessions were divided into two subpopulations with presence of allele mixture between these two groups. Based on the PCA, we were able to verify a narrow genetic base of accessions belonging to the Andean gene pool, as well as a vast genetic diversity among the accessions from the Middle American gene pool. The knowledge on the genetic diversity among the accessions is of extreme importance to subsidize the common bean breeding programs in Northeast Brazil, and to explore the variability existing in cultivars adapted to the specific bioclimatic conditions.

Population structure and genetic diversity in common bean accessions from Northeast Brazil

Population structure and genetic diversity in common bean accessions from Northeast Brazil

New genomic regions for resistance to anthracnose (Colletotrichum lindemuthianum) through GBS-based genome-wide association study in common bean (Phaseolus vulgaris)

The most effective strategy to manage bean anthracnose (ANT), caused by Colletotrichum lindemuthianum, is the use of resistant cultivars. This study aimed to evaluate resistance reactions of common bean accessions to C. lindemuthianum races 2, 9 and 1545, and to perform genome-wide association study (GWAS). Hence, 89 accessions were phenotyped and genotyped through genotyping by sequencing (GBS). As a result, 48 accessions resistant to all evaluated races were identified. Moreover, single-nucleotide polymorphisms (SNP) significantly associated with resistance were identified in new regions of chromosomes Pv03, Pv05 and Pv06, and also at the beginning of Pv04 and end of Pv11, where other resistance genes have been previously found. In reference genome these regions contain model genes encoding resistance proteins as kinases, leucine-rich repeats, receptor-like protein, copper transport protein, pentatricopeptide repeats, calcium-dependent protein kinases, and ethylene-responsive transcription factors. The genomic regions associated to ANT resistance found in this study should be validated for further use in marker assisted selection and gene pyramiding. Together with new sources of ANT resistance our findings show promise for further crop improvement.

The aquaporin gene PvXIP1;2 conferring drought resistance identified by GWAS at seedling stage in common bean.

A whole-genome resequencing-derived SNP dataset used for genome-wide association analysis revealed 12 loci significantly associated with drought stress based on survival rate after drought stress at seedling stage. We further confirmed the drought-related function of an aquaporin gene (PvXIP1;2) located at Locus_10. A variety of adverse conditions, including drought stress, severely affect common bean production. Molecular breeding for drought resistance has been proposed as an effective and practical way to improve the drought resistance of common bean. A genome-wide association analysis was conducted to identify drought-related loci based on survival rates at the seedling stage using a natural population consisting of 400 common bean accessions and 3,832,340 SNPs. The coefficient of variation ranged from 40.90 to 56.22% for survival rates in three independent experiments. A total of 12 associated loci containing 89 significant SNPs were identified for survival rates at the seedling stage. Four loci overlapped in the region of the QTLs reported to be associated with drought resistance. According to the expression profiles, gene annotations and references of the functions of homologous genes in Arabidopsis, 39 genes were considered potential candidate genes selected from 199 genes annotated within all associated loci. A stable locus (Locus_10) was identified on chromosome 11, which contained LEA, aquaporin, and proline-rich protein genes. We further confirmed the drought-related function of an aquaporin (PvXIP1;2) located at Locus_10 by expression pattern analysis, phenotypic analysis of PvXIP1;2-overexpressing Arabidopsis and Agrobacterium rhizogenes-mediated hairy root transformation systems, indicating that the association results can facilitate the efficient identification of genes related to drought resistance. These loci and their candidate genes provide a foundation for crop improvement via breeding for drought resistance in common bean.

Proteomic Analysis of Common Bean (Phaseolus vulgaris L.) by Two-Dimensional Gel Electrophoresis and Mass Spectrometry

The modern cultivated common bean (Phaseolus vulgaris) has evolved from wild common beans distributed in Central America, Mexico and the Andean region of South America. It has been reported that wild common bean accessions have higher levels of protein content than the domesticated dry bean cultivars. However, there is limited proteomic analysis of wild or domesticated common beans. In this investigation, we reported a proteomic analysis of a wild bean from Mexico. We utilized the TCA/Acetone method for protein extraction, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) for protein separation, and subsequent mass spectrometry (MS) for protein identification. Proteins were separated in the first dimension using pH range from 4-7. A total of 237 protein spots from the second dimension were isolated, digested with trypsin, and analyzed by MALDI/TOF/TOF mass spectrometry. We identified 141 protein spots by searching NCBI non redundant databases using the Mascot search engine and found a total of 43 unique proteins. Gene Ontology (GO) analysis was employed to understand the molecular processes in which the identified common bean proteins are involved. The majority of proteins are involved in binding (41.5%) and catalytic activity (35.8%), followed by nutrient reservoir activity (7.5%), antioxidant activity (1.9%), transporter activity (3.8%), enzyme regulator activity (3.8%), structural molecule activity (1.9%), and electron carrier activity (3.8%). The results indicate that TCA/Acetone extraction and 2D-PAGE is efficient in separating common bean proteins. Further identification of these proteins by MS demonstrates the quality of this protein extraction method. These results will be useful for the development of value added common beans by alteration of protein components.

Metabolomics profile responses to changing environments in a common bean (Phaseolus vulgaris L.) germplasm collection

Metabolomics is one of the most powerful -omics to assist plant breeding. Despite the recognized genetic diversity in Portuguese common bean germplasm, details on its metabolomics profiles are still missing. Aiming to promote their use and to understand the environment’s effect in bean metabolomics profiles, 107 Portuguese common bean accessions, cropped under contrasting environments, were analyzed using spectrophotometric, untargeted and targeted mass spectrometry approaches. Although genotype was the most relevant factor on bean metabolomics profile, a clear genotype × environment interaction was also detected. Multivariate analysis highlighted, on the heat-stress environment, the existence of higher levels of salicylic acid, and lower levels of triterpene saponins. Three clusters were defined within each environment. White accessions presented the lowest content and the colored ones the highest levels of prenol lipids and flavonoids. Sources of interesting metabolomics profiles are now identified for bean breeding, focusing either on local or on broad adaptation.

Genetic diversity and inter-gene pool introgression of Mesoamerican Diversity Panel in common beans.

Brazil is among the largest producers and consumers of common bean (Phaseolus vulgaris L.) and can be considered a secondary center of diversity for the species. The aim of this study was to estimate the genetic diversity, population structure, and relationships among 288 common bean accessions in an American Diversity Panel (ADP) genotyped with 4,042 high-quality single nucleotide polymorphisms (SNPs). The results showed inter-gene pool hybridization (hybrids) between the two main gene pools (i.e., Mesoamerican and Andean), based on principal component analysis (PCA), discriminant analysis of principal components (DAPC), and STRUCTURE analysis. The genetic diversity parameters showed that the Mesoamerican group has higher values of diversity and allelic richness in comparison with the Andean group. Considering the optimal clusters (K), clustering was performed according to the type of grain (i.e., market group), the institution of origin, the period of release, and agronomic traits. A new subset was selected and named the Mesoamerican Diversity Panel (MDP), with 205 Mesoamerican accessions. Analysis of molecular variance (AMOVA) showed low genetic variance between the two panels (i.e., ADP and MDP) with the highest percentage of the limited variance among accessions in each group. The ADP showed occurrence of high genetic differentiation between populations (i.e., Mesoamerican and Andean) and introgression between gene pools in hybrids based on a set of diagnostic SNPs. The MDP showed better linkage disequilibrium (LD) decay. The availability of genetic variation from inter-gene pool hybridizations presents a potential opportunity for breeders towards the development of superior common bean cultivars.

Genome-Environment Association Analysis for Bio-Climatic Variables in Common Bean (Phaseolus vulgaris L.) from Brazil.

Abiotic stress is a limiting factor for common bean (Phaseolus vulgaris L.) production globally. The study of the genotypic, phenotypic, and bio-climatic variables in a broad set of accessions may assist the identification of genomic regions involved in the climatic adaptation of the common bean. We conducted a genotyping-by-sequencing analysis using 28,823 SNPs on 110 georeferenced common bean accessions from Brazil to discover associations between SNPs and bio-climatic indexes. The population structure analysis clustered the accessions into two groups corresponding to the Andean and Mesoamerican gene pools. Of the 19 bioclimatic variables, 17 exhibited a significant association with SNPs on chromosomes Pv01, Pv02, Pv03, Pv04, Pv06, Pv09, Pv10, and Pv11 of common bean. Ten candidate genes were associated with specific bio-climatic variables related to temperature and precipitation. The candidate genes associated with this significant Pv09 region encode a Platz transcription factor family protein previously reported to be an essential regulator of drought stress. The SNP markers and candidate genes associated with the bio-climatic variables should be validated in segregating populations for water stress, which could further be used for marker-assisted selection. As a result, bean breeding programs may be able to provide advances in obtaining drought-tolerant cultivars.

Genetic dissection of days to flowering via genome-wide association studies in Turkish common bean germplasm

Common bean is a nutrient-dense legume crop serving as a source of food for millions of people. Characterization of unexplored common bean germplasm to unlock the phenotypic and genetic variations is still needed to explore the breeding potential of this crop. The current study aimed to dissect the genetic basis having association for days to flowering (DF). A total of 188 common bean accessions collected from 19 provinces of Turkey were used as plant material under five environments and two locations. Analysis of variance (ANOVA) revealed that genotypes and genotype by environment interaction have significant effects on DF. A total of 10 most stable accessions were evaluated from stability analysis. Overall maximum (75) and minimum (54) DF were observed for Hakkari-51 and Mus-46 accessions, respectively. The implemented constellation plot divided studied germplasm according to their DF and growth habit. A total of 7900 DArTseq markers were used for association analysis. Mixed linear model using the Q + K Model resulted a total of 18 DArTseq markers from five environments. DArT-8668385 marker identified in Bolu during 2016 was also associated with DF in Sivas during 2017. Combined data of five years resulted a total of four markers (DArT-22346534, DArT-3369768, DArT-3374613, and DArT-3370801) having significant association ( p < 0.01 ) for DF. DArT-22346534 present on Pv 08 accounted a maximum of 9.89% variation to the studied trait. A total of four putative candidate genes were predicted from sequences reflecting homology to identified four DArTseq markers. We envisage that exploitation of identified DArTseq markers will hopefully beneficial for the development of new common bean varieties having better adaptation ability to changing climatic conditions.The online version contains supplementary material available at 10.1007/s12298-021-01029-8.

Genome-Wide Association Study and Genomic Prediction for Soybean Cyst Nematode Resistance in USDA Common Bean (Phaseolus vulgaris) Core Collection.

Soybean cyst nematode (SCN, Heterodera glycines) has become the major yield-limiting biological factor in soybean production. Common bean is also a good host of SCN, and its production is challenged by this emerging pest in many regions such as the upper Midwest USA. The use of host genetic resistance has been the most effective and environmentally friendly method to manage SCN. The objectives of this study were to evaluate the SCN resistance in the USDA common bean core collection and conduct a genome-wide association study (GWAS) of single nucleotide polymorphism (SNP) markers with SCN resistance. A total of 315 accessions of the USDA common bean core collection were evaluated for resistance to SCN HG Type 0 (race 6). The common bean core set was genotyped with the BARCBean6K_3 Infinium BeadChips, consisting of 4,654 SNPs. Results showed that 15 accessions were resistant to SCN with a Female Index (FI) at 4.8 to 9.4, and 62 accessions were moderately resistant (10 < FI < 30) to HG Type 0. The association study showed that 11 SNP markers, located on chromosomes Pv04, 07, 09, and 11, were strongly associated with resistance to HG Type 0. GWAS was also conducted for resistance to HG Type 2.5.7 and HG Type 1.2.3.5.6.7 based on the public dataset (N = 276), consisting of a diverse set of common bean accessions genotyped with the BARCBean6K_3 chip. Six SNPs associated with HG Type 2.5.7 resistance on Pv 01, 02, 03, and 07, and 12 SNPs with HG Type 1.2.3.5.6.7 resistance on Pv 01, 03, 06, 07, 09, 10, and 11 were detected. The accuracy of genomic prediction (GP) was 0.36 to 0.49 for resistance to the three SCN HG types, indicating that genomic selection (GS) of SCN resistance is feasible. This study provides basic information for developing SCN-resistant common bean cultivars, using the USDA core germ plasm accessions. The SNP markers can be used in molecular breeding in common beans through marker-assisted selection (MAS) and GS.