Common Bean Landraces Research Articles

Genetic Variability Analysis and Association of Traits in Common Bean (Phaseolus vulgaris L.) Landraces Collected from Ethiopia at Jimma

This study was conducted on one hundred common bean landraces at the Jimma Agricultural Research Center, Melko, with the objective of assessing genetic variability and association of traits in common bean landraces collected from different parts of Ethiopia. The experiment was laid out in a simple lattice design with two replications. Analysis of variance showed significant differences among genotypes for all traits. This highly significant difference indicates the existence of large variability among genotypes. High phenotypic coefficients of variation and genotypic coefficients of variation were obtained for plant height (19.43, 11.73), pod length (11.27, 10.69), and 100-seed weight (15.42, 12.74). High heritability in the broad sense was found for days to 50% flowering (66.98), days to 90% maturity (87.43), pod length (90.03), pod width (78.23), harvest index (98.67), and 100-seed weight (68.31). High genetic advance as a percentage of mean with high heritability was obtained for pod length, pod width, harvest index, and hundred seed weight. Grain yield had a positive and significant association with pod length (rp = 0.153 ∗ , rg = 0.282 ∗ ∗ ) and 100-seed weight (rp = 0.294 ∗ ∗ , rg = 0.492 ∗ ∗ ). Hundred seed weight exerted the highest positive direct effect (0.294) on grain yield at genotypic level. The D2 classified landraces into 7 clusters and one solitary, which makes them moderately divergent. The highest inter-cluster distance was observed between clusters VII and IV. The first five principal components with eigenvalues greater than one altogether explained about 79.56% of the total variation. In conclusion, the top high-yielding landraces, namely, P#1247, P#1092, P#1077, P#861, P#990, P#763, P#58, and P#857, should be included in the next breeding program. 100-seed weight had the highest direct effect and a positive significant association with grain yield. Thus, it should be considered as the selection criteria for further common bean yield improvement. However, the current result is merely indicative and cannot be used to draw definite conclusions. Therefore, the experiment should be replicated in different locations and seasons for greater consistency.

A Multi-Level Approach as a Powerful Tool to Identify and Characterize Some Italian Autochthonous Common Bean (Phaseolus vulgaris L.) Landraces under a Changing Environment.

A prime role in matters of agrobiodiversity is held by landraces, which serve as a repository gene pool able to meet sustainable development goals and to face the ongoing challenges of climate change. However, many landraces are currently endangered due to environmental and socio-economic changes. Thus, effective characterization activities and conservation strategies should be undertaken to prevent their genetic and cultural erosion. In the current study, the morphological, genetic, and biochemical analyses were integrated with stress response-related studies to characterize the diversity of seven Italian autochthonous common bean landraces. The results showed that the morphological descriptors and the neutral molecular markers represent powerful tools to identify and distinguish diversity among landrace populations, but they cannot correlate with the stress tolerance pattern of genetically similar populations. The study also supported the use of proline as a biochemical marker to screen the most salt-sensitive bean landraces. Thus, to fully elucidate the future dynamics of agrobiodiversity and to establish the basis for safeguarding them while promoting their utilization, a multi-level approach should always be included in any local and national program for the characterization/conservation/use of genetic resources. This study should represent the basis for further joint research that effectively contributes to set/achieve Italian priorities towards sustainability in the framework of emerging environmental, societal, and economic challenges.

Genotype Selection, and Seed Uniformity and Multiplication to Ensure Common Bean (Phaseolus vulgaris L.) var. Liborino

Seed uniformity and stability testing, and multiplication, are key steps in the seed supply chain of the common bean (Phaseolus vulgaris L.) and other crops. Optimizing agronomical practices in these phases can ultimately ensure seed quality and availability, and germplasm prospective utilization. However, farmers have rarely standardized seed testing and propagation protocols in local common bean landraces conserved in situ. An example of this is the Liborino variety (var.), a promising yellow Andean common bean known for its presumably high digestibility and adaptation to the local conditions of the Cauca river canyon (northwest Andes of Colombia), but likely experiencing genetic erosion after decades of suboptimal propagation. Therefore, this work intended to evaluate and select locally adapted genotypes of common bean var. Liborino for commercial use, to be later multiplied, evaluated by participatory breeding, and eventually shared with farmers. Specifically, we evaluated 44 accessions of var. Liborino common bean in six adaption and yield field trials in the Cauca river canyon at 1100 and 1400 m a.s.l, and in AGROSAVIA’s “La Selva” research station at 2100 m a.s.l. In parallel, we carried out standardized seed multiplication of a Liborino genotype using best practices to guarantee uniformity and stability. From the 44 accessions, nine were well adapted to the tested local conditions. Four of these accessions exhibited a bush type growth habit, while the remaining five were climbers. The trials revealed maximum average extrapolated yields of up to 1169.4 ± 228.4 kg ha−1 for the bush types (G8152) and up to 1720.0 ± 588.4 kg ha−1 for the climbers (G51018), both at 2100 m a.s.l. Three climbing accessions matched farmers’ expectations for seed coat color and shape, according to a participatory selection exercise. Uniform and stable seed of the selected genotype was delivered in 2022 to 39 farmers, ~6.5 kg of seeds per farmer. Our results will allow implementing bean genetic improvement pipelines, promoting var. Liborino commercialization, and boosting the economic and sustainable development of the rural communities in the Cauca river canyon. Seed uniformity testing and multiplication pipelines must be extended to other bean landraces conserved in situ.

Determining Genetic Diversity and Population Structure of Common Bean (Phaseolus vulgaris L.) Landraces from Türkiye Using SSR Markers

Assessment of genetic diversity among different varieties helps to improve desired characteristics of crops, including disease resistance, early maturity, high yield, and resistance to drought. Molecular markers are one of the most effective tools for discovering genetic diversity that can increase reproductive efficiency. Simple sequence repeats (SSRs), which are codominant markers, are preferred for the determination of genetic diversity because they are highly polymorphic, multi-allelic, highly reproducible, and have good genome coverage. This study aimed to determine the genetic diversity of 40 common bean (Phaseolus vulgaris L.) landraces collected from the Ispir district located in the Northeast Anatolia region of Türkiye and five commercial varieties using SSR markers. The Twenty-seven SSR markers produced a total of 142 polymorphic bands, ranging from 2 (GATS91 and PVTT001) to 12 (BM153) alleles per marker, with an average number of 5.26 alleles. The gene diversity per marker varied between 0.37 and 0.87 for BM053 and BM153 markers, respectively. When heterozygous individuals are calculated proportional to the population, the heterozygosity ranged from 0.00 to 1.00, with an average of 0.30. The expected heterozygosity of the SSR locus ranged from 0.37 (BM053) to 0.88 (BM153), with an average of 0.69. Nei’s gene diversity scored an average of 0.69. The polymorphic information content (PIC) values of SSR markers varied from 0.33 (BM053) to 0.86 (BM153), with an average of 0.63 per locus. The greatest genetic distance (0.83) was between lines 49, 50, 53, and cultivar Karacaşehir-90, while the shortest (0.08) was between lines 6 and 26. In cluster analysis using Nei’s genetic distance, 45 common bean genotypes were divided into three groups and very little relationship was found between the genotypes and the geographical distances. In genetic structure analysis, three subgroups were formed, including local landraces and commercial varieties. The result confirmed that the rich diversity existing in Ispir bean landraces could be used as a genetic resource in designing breeding programs and may also contribute to Türkiye bean breeding programs.

Genetic diversity of common bean (Phaseolus vulgaris L.) ecotypes from Pakistan using Simple Sequence Repeats

Common bean (Phaseolus vulgaris L.) is a legume crop grown all over the world and is a very important food of mountain population of Pakistan for protein intake. The Western Himalayan Mountains are rich in biodiversity including unexplored landraces of the common bean crop. Unfortunately, very little attention has been given to this valuable crop in Pakistan, and it is being exported, majorly from Ethiopia, to meet the country’s requirements. The exploitation, utilization, preservation and multiplication of existing germplasm within the area are very important for sustainable production of the crop and enhancing the nutrition value for the local community in mountain regions. A research study was conducted for evaluation of biological diversity of common bean landraces from Azad Kashmir and Northern areas of Pakistan using morpho-physiological and molecular markers. Thirty-five common bean ecotypes along with one check variety were collected from different altitudes of Azad Kashmir and Northern Pakistan and screened for biological diversity. Morphological characterization revealed high genetic diversity in parameters including stem anthocyanin, growth type, days to flowering, pods/plant and 100 seeds weight. Genomic characterization using SSR markers, for allelic diversity evaluation among germplasm, also provided diverse profile with 83.3% polymorphism in banding pattern. The bulk of gene pool diversity evaluated within bean landraces may help to initiate breeding program for common bean improvement.

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.

WB-216: A common bean (Phaseolus vulgaris L.) landrace with multiple characteristics from Western Himalayan Kashmir

WB-216: A common bean (Phaseolus vulgaris L.) landrace with multiple characteristics from Western Himalayan Kashmir

Estimation of the Variation Coefficient and Some Local Genetical Resources of Some Common Bean

The present investigation was carried out during two successive summer seasons of years 2019 and 2020 at the Faculty of Agriculture (Saba Basha), Alexandria University and the laboratory of the vegetable seeds of Sabahya Horticulture Research Station, Alexandria Governorate, Egypt to evaluate six local cultivars and landraces of common bean for some morphological characters, yield and its components as well as estimate some genetic parameters and analysis

Morphoagronomic characterization and genetic variability analysis of common bean landraces in Kashmir Himalayas: implications for yield enhancement

Morphoagronomic characterization and genetic variability analysis of common bean landraces in Kashmir Himalayas: implications for yield enhancement

Genetic diversity of common bean landraces on seed imbibition and some quality traits

Genetic diversity of common bean landraces on seed imbibition and some quality traits

Assessment of the Origin and Diversity of Croatian Common Bean Germplasm Using Phaseolin Type, SSR and SNP Markers and Morphological Traits.

Landraces represent valuable genetic resources for breeding programmes to produce high-yielding varieties adapted to stressful environmental conditions. Although the common bean (Phaseolus vulgaris L.) is an economically important food legume for direct human consumption worldwide, common bean production in Croatia is based almost exclusively on landraces and there is no common bean breeding program. Information on phaseolin type and results of population structure and genetic diversity obtained by analysis of SSR and SNP markers, in combination with the morphological characterization of 174 accessions of 10 common bean landraces (morphotypes), enabled thorough classification of accessions. The accessions were classified into phaseolin type H1 (“S”) of Mesoamerican origin and phaseolin types H2 (“H” or “C”) and H3 (“T”) of Andean origin. By applying distance- and model-based clustering methods to SSR markers, the accessions were classified into two clusters at K = 2 separating the accessions according to the centres of origin, while at K = 3, the accessions of Andean origin were further classified into two clusters of accessions that differed in phaseolin type (H2 and H3). Using SNP markers, model-based analysis of population structure was performed, the results of which were consistent with those of SSR markers. In addition, 122 accessions were assigned to 14 newly formed true-type morphogenetic groups derived from three different domestication events: (1) Mesoamerican (H1A) (“Biser”, “Kukuruzar”, “Tetovac”, “Trešnjevac”), (2) Andean—indeterminate type (H2B1) (“Dan noć”, “Sivi”, “Puter”, ”Sivi prošarani”, “Trešnjevac”) and (3) Andean—determinate type (H3B2) (“Bijeli”, “Dan noć”, “Puter”, “Trešnjevac”, “Zelenčec”). The rest of the accessions could represent putative hybrids between morphogenetic groups. The differences between the true-type groups of accessions were further analysed based on nine quantitative traits, and the subsets of traits that best distinguish among centres of origin (A: Mesoamerican, B: Andean) and genetic groups (H1A, H2B1, H3B2) were proposed.

Genome-Wide Association Studies of Mineral Content in Common Bean.

Micronutrient malnutrition is one of the main public health problems in many parts of the world. This problem raises the attention of all valuable sources of micronutrients for the human diet, such as common bean (Phaseolus vulgaris L.). In this research, a panel of 174 accessions representing Croatian common bean landraces was phenotyped for seed content of eight nutrients (N, P, K, Ca, Mg, Fe, Zn, and Mn), and genotyped using 6,311 high-quality DArTseq-derived SNP markers. A genome-wide association study (GWAS) was then performed to identify new genetic sources for improving seed mineral content. Twenty-two quantitative trait nucleotides (QTN) associated with seed nitrogen content were discovered on chromosomes Pv01, Pv02, Pv03, Pv05, Pv07, Pv08, and Pv10. Five QTNs were associated with seed phosphorus content, four on chromosome Pv07, and one on Pv08. A single significant QTN was found for seed calcium content on chromosome Pv09 and for seed magnesium content on Pv08. Finally, two QTNs associated with seed zinc content were identified on Pv06 while no QTNs were found to be associated with seed potassium, iron, or manganese content. Our results demonstrate the utility of GWAS for understanding the genetic architecture of seed nutritional traits in common bean and have utility for future enrichment of seed with macro– and micronutrients through genomics-assisted breeding.

Introgression of anthracnose resistance into the background of locally adapted common bean landraces

Adequate knowledge, access and introgression of genetic diversity available in cultivated and wild relatives are pre-requisites for widening the genetic base of cultivars to sustain genetic improvement. An attempt was made to screen anthracnose resistance in 33 indigenous and exotic accessions of common bean (Phaseolus vulgaris L.) belonging to primary, secondary, tertiary and quaternary gene pools including three popular and widely cultivated landraces of North-Western Indian Himalayas. The cultivated and wild species of common bean were introgressed into the backgrounds of landraces, which resulted in the development of 22 crosses comprising 6 each of intra and interspecific crosses with P. vulgaris and P. coccineus, 3 with P. acutifolius, 2 with P. lunatus and 5 backcrosses. The hybridity of these crosses was confirmed using morphological and molecular markers. The interspecific crosses of P. vulgaris × P. coccineus, P. vulgaris × P. acutifolius and P. vulgaris × P. lunatus were attempted for the first time in India using in-vitro approaches. Further hybrid plants were grown to maturity following embryo rescue protocol, but all showed different developmental abnormalities. The overall establishment of successful hybrids and their complete development was the maximum in cross of Bhaderwah Local × Poonch Local (18.28%) and the minimum in Bhaderwah Local × IC258276 and Bhaderwah Local × IC328372 (0.5%). The results of the present study revealed that wild relatives of common bean viz. P. coccineus, P. acutifolius and P. lunatus are an excellent source of resistance against anthracnose, which can be exploited for diversification of cultivated gene pool. These resistant genetic resources could also be shared among common bean researchers in the country or elsewhere under Standard Material Transfer Agreement for strengthening ongoing crop improvement programmes.

Environmentally stable common bean genotypes for production in different agro-ecological zones of Tanzania

Genotype by environment interaction (GxE) complicates the process of selecting genotypes suitable for quantitative traits like seed yield in beans, hence slows down the development and release of varieties by breeding programs. GxE study on seed yield in beans enables identification of stable genotypes across sites and best site(s) for discriminating the tested genotypes in terms of seed yield. The purpose of this study was to evaluate the influence of the environment, genotype, and genotype by environment interaction on seed yield stability and adaptability of common bean landraces, lines, and improved varieties across three different agro-ecologies in Tanzania. The 99 common bean genotypes (Landraces, lines, and improved varieties) were planted following alpha lattice design in three replications each contained five blocks with 20 plots. Soil properties from the experimental sites, days to 75% flowering, Seed yield, 100 seed weight, number of seeds/pod, and number of pods/plant were recorded. Data on seed yield and its components were analyzed using Additive main effect and multiplicative interaction (AMMI), genotype main effects plus genotype × environment interaction (GGE), and yield stability index (YSI). The AMMI revealed very highly significant (P ≤ 0.001) effects of genotypes, environmental, and genotype × environment interaction on all the traits. AMMI analysis revealed that genotype main effects accounted for 39.3% of the total sum square of seed yield, whereas the environment and genotype × environmental interaction accounted for 31.4% and 26.8 % respectively. Genotype main effects largely influenced the variation in days to 75% flowering (55.5%), number of pods/plant (49.2%), number of seeds/pod (73.3%), and 100 seed weight (71.2%). Among soil properties recorded, available soil phosphorus, soil pH, soil exchangeable K, Ca, and Na had a strong positive association with common bean seed yield, while soil organic carbon and total nitrogen exhibited a strong negative association with seed yield. GGE revealed that E1 (TARI-Selian) was the most discriminative and representative site for common bean genotypes seed yield. Based on the yield stability index, the most stable and high seed yielding genotypes were ACC 714, Selian 14, Selian 9, Katuku, and Msolini. The identified high seed yielding and stable genotypes can be further tested in participatory variety selection involving farmers and later on released as varieties and can also be used for different breeding purposes in different agro-ecologies of Tanzania.

Genetic diversity and selection of bean landraces and cultivars based on technological and nutritional traits

This study was undertaken to evaluate the genetic variability of common bean landraces and modern cultivars for 15 technological- and nutritional-quality traits; analyze the correlations between these traits; investigate genetic dissimilarity between the cultivars; and select superior common bean cultivars for human nutrition. Three experiments were carried out between the years 2017 and 2018 in which 49 common bean cultivars were evaluated. A significant genotype × environment interaction effect was observed for all traits. Mass of 100 grains was positively correlated with grain length (r = 0.78) and cooking time (r = 0.59) and negatively correlated with magnesium concentration (r = −0.63). The L* (grain lightness) and a* (color variation from green to red) values were more important in differentiating the cultivars. Eight and three groups of cultivars were formed using the canonical-variable and simple-linkage analyses, respectively. These analyses are not in agreement on the definition of groups and on the composition of the different groups. The cultivars Preguiçoso, Inhoque, Carioca Vila Nova do Sul, Pérola, Trindade, Argentino, Turrialba, Banana, Vagem Roxa and Paraná have high technological quality and high concentrations of various minerals; therefore, their use is recommended for human nutrition and breeding programs.

Variation in protein and amino acids content among landraces of common bean (Phaseolus vulgaris L.)

Native bean populations (Phaseolus vulgaris L.) provide bioactive and nutrient compounds; however, their amino acid profiles are unknown. Therefore, the aim of this study is to evaluate the protein content and amino acid profile of 46 native bean populations cultivated by small farmers in Oaxaca, Mexico, and compare them with that of commercial beans. Through high-performance liquid chromatography (HPLC), 16 amino acids were identified and quantified in all samples. The region of origin influenced the concentrations of amino acids. The Santa Lucia Miahuatlan populations stood out for their high content of isoleucine, threonine, methionine, arginine, serine, alanine, tyrosine, and cysteine. Amino acid content showed high variability among the populations; accessions labeled as FSLM22, FSLM27, FSLM28, and FSLM32 were enriched in aliphatic, hydroxylated, aromatic, acidic, and basic amino acids, while the FSLM14, FSLM17, and FSLM18 populations had the highest concentrations of sulfur amino acids. The FSLM01, FSLM22, FSLM27, FSLM28, FSLM30, and FSLM32 populations frequently displayed the highest concentrations of essential amino acids. The findings show that samples of native populations are highly variable in amino acid content due to the genetic characteristics of cultivated beans, environmental and agroecological influences, and crop management by farmers. The beans populations stood out can be used for direct use or a basis for the initiation of a breeding program.

North-Western Himalayan Common Beans: Population Structure and Mapping of Quantitative Anthracnose Resistance Through Genome Wide Association Study.

Common bean (Phaseolus vulgaris L.) is an important legume crop of north-western (NW) Himalayan region and the major disease that causes catastrophic loss to the crop is anthracnose, which is caused by Colletotrichum lindemuthianum. The pathogen is highly diverse and most of the commercial cultivars are susceptible to different races prevalent in the region. The lack of information on the genomic regions associated with anthracnose resistance in NW Himalayan common bean population prompted us to dissect Quantitative Resistance Loci (QRLs) against major anthracnose races. In this study, 188 common bean landraces collected from NW region were screened against five important anthracnose races and 113 bean genotypes showed resistance to one or multiple races. Genotyping by sequencing (GBS) was performed on a panel of 192 bean lines (4 controls plus 188 Indian beans) and 22,589 SNPs were obtained that are evenly distributed. Population structure analysis of 192 bean genotypes categorized 188 Indian beans into two major clusters representing Andean and Mesoamerican gene pools with obvious admixtures. Many QRLs associated with anthracnose resistance to Indian C. lindemuthianum virulences (race 3, 87, and 503) are located at Pv04 within the gene models that encode typical resistance gene signatures. The QRLs associated with race 73 are located on Pv08 and overlaps with Co-4 anthracnose resistance gene. A SNP located at distal end of Pv11 in a gene model Phvul.011G202300 which encodes a LRR with a typical NB-ARC domain showed association with race 73 resistance. Common bean genomic regions located at Pv03, Pv09, and Pv11 showed association with resistance to anthracnose race 2047. The present study showed presence of many novel bean genomic regions associated with anthracnose resistance. The presence of Co-4 and Co-2 genes in our material is encouraging for breeding durable anthracnose resistant cultivars for the region.

Genetic Diversity, Nitrogen Fixation, and Water Use Efficiency in a Panel of Honduran Common Bean (Phaseolus vulgaris L.) Landraces and Modern Genotypes.

Common bean (Phaseolus vulgaris L.) provides critical nutrition and a livelihood for millions of smallholder farmers worldwide. Beans engage in symbiotic nitrogen fixation (SNF) with Rhizobia. Honduran hillside farmers farm marginal land and utilize few production inputs; therefore, bean varieties with high SNF capacity and environmental resiliency would be of benefit to them. We explored the diversity for SNF, agronomic traits, and water use efficiency (WUE) among 70 Honduran landrace, participatory bred (PPB), and conventionally bred bean varieties (HON panel) and 6 North American check varieties in 3 low-N field trials in Ontario, Canada and Honduras. Genetic diversity was measured with a 6K single nucleotide polymorphism (SNP) array, and phenotyping for agronomic, SNF, and WUE traits was carried out. STRUCTURE analysis revealed two subpopulations with admixture between the subpopulations. Nucleotide diversity was greater in the landraces than the PPB varieties across the genome, and multiple genomic regions were identified where population genetic differentiation between the landraces and PPB varieties was evident. Significant differences were found between varieties and breeding categories for agronomic traits, SNF, and WUE. Landraces had above average SNF capacity, conventional varieties showed higher yields, and PPB varieties performed well for WUE. Varieties with the best SNF capacity could be used in further participatory breeding efforts.

Preserving Biodiversity in Marginal Rural Areas: Assessment of Morphological and Genetic Variability of a Sicilian Common Bean Germplasm Collection.

The historical cultivation of common bean (Phaseolus vulgaris L.) has resulted in the development of local populations/cultivars in restricted Italian rural areas. Many common bean landraces, still cultivated in small mountain areas from Sicily, have become outdated and endangered due to the commercial varieties spreading. These accessions are poorly known but often represent a genetic heritage to be preserved and enhanced. The ex situ conservation of fifty-seven Sicilian common bean landraces was carried out at the “Living Plants Germplasm Bank” at Ucria (Messina, Italy), founded by the Nebrodi Regional Park, together with the “Sicilian Plant Germplasm Repository” of University of Palermo (SPGR/PA). To assess the germplasm genetic diversity, nineteen morphological traits and eight Simple Sequence Repeats (SSRs) were used. Genetic distances among landraces were calculated to construct a clustering tree by using unweighted pair group method arithmetic (UPGMA). Seed germplasm diversity of Sicilian common bean varied from 80.7% to 93.3%, based on six seed descriptors and six leaf, flower, and pod descriptors, respectively, while cluster genetic analysis depicted a clear separation among all the 57 landraces. Principal coordinates (PCoA) and STRUCTURE analyses showed a prevalent rate of admixture between Mesoamerican and Andean gene pools in Sicilian common bean collection, confirming its heterogeneity. The observed high level of diversity evidenced the needs to adopt accurate criterion to plan a definitive ex situ germplasm collection to share agrobiodiversity with local farmers and to avoid any further loss of genetic resources in rural and protected areas.

Population Development of Bean Weevils (Coleoptera: Chrysomelidae: Bruchinae) in Landrace Varieties of Cowpeas and Common Beans

Bean weevils (Coleoptera: Chrysomelidae: Bruchinae) are responsible for large quantity losses of cowpea (Vigna unguiculata (L.) Walp.; Fabaceae) and common bean (Phaseolus vulgaris L.; Fabaceae). The magnitude of damage is related to the grains’ varietal susceptibility. The objective of this study was to determine the population development rates of Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) in 4 landrace varieties of cowpea (var. ‘UFAC-B01,’ ‘UFAC-MV01,’ ‘UFAC-MG01,’ and ‘UFAC-Q01’), as well as the population development rates of Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae) in 4 landrace varieties of common bean (var. ‘UFAC-G01,’ ‘UFAC-M01,’ ‘UFAC-P01,’ and ‘UFAC-R01’). We determined the population development rates of the weevils in each variety. The weight of 100 grains (g) and the percentage of grain weight loss were measured, and correlations between these variables were analyzed. The statistical design was completely randomized, with 4 replications. Varieties UFAC-Q01 (cowpea) and UFAC-R01 (common bean) showed lower insect population development rates than other varieties. Although variations were found in the weight of 100 grains and grain weight loss, no significant correlations with bean weevil population development were observed. The cowpea and common bean landrace varieties from the southwestern Amazon region are important sources of resistance to bean weevils. The UFAC-Q01 cowpea variety and the UFAC-R01 common bean variety showed lower susceptibility to C. maculatus and Z. subfasciatus, respectively. Resumo Os bruquideos (Coleoptera: Chrysomelidae: Bruchinae) sao responsaveis por elevadas perdas na qualidade do caupi (Vigna unguiculata (L.) Walp.; Fabaceae) e feijao comum (Phaseolus vulgaris L.; Fabaceae), sendo que a magnitude dos danos esta relacionados a susceptibilidade varietal dos graos. O objetivo desta investigacao foi determinar as taxas de desenvolvimento populacional de Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) em quarto variedades crioulas de caupi (var. ‘UFAC-B01,’ ‘UFAC-MV01,’ ‘UFAC-MG01,’ e ‘UFAC-Q01’), bem como a a taxa de desenvolvimento populacional de Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae) em quarto variedades crioulas de feijao comum (vbean weevilsar. ‘UFAC-G01,’ ‘UFAC-M01,’ ‘UFAC-P01,’ e ‘UFAC-R01’). Foram realizados bioensaios para determinar as taxas de desenvolvimento populacional dos bruquideos em cada variedade, e avaliou-se a massa de 100 graos (g), perda de massa (%) e foram realizadas analises de correlacao entre estes fatores. O delineamento estatistico foi inteiramente casualizado com quatro repeticoes. As variedades UFAC-Q01 e UFAC-R01 de caupi e feijao comum, respectivamente, apresentaram menores taxas de desenvolvimento populacional, comparando-se com as demais variedades. Embora tenha havido variacao da massa de 100 graos, perda de massa, nao foram constadas correlacoes significativamente com o desenvolvimento populacional dos bruquideos. As variedades landraces de caupi e feijao comum, oriundos da Amazonia Sul-Ocideltal, constituem importantes fontes de resistencia para bruquideos, sendo que as variedades UFAC-Q01 e UFAC-R01 de caupi e feijao comum apresentaram menor susceptibilidade ao ataque de C. maculatus e Z. subfasciatus. Key Words: Vigna unguiculata; Phaseolus vulgaris; varietal susceptibility; storage; bruchids View this article in BioOne