Common Bean Germplasm Research Articles

Bean dwarf mosaic virus: a model system for the study of viral movement

Bean dwarf mosaic virus-[Colombia:1987] (BDMV-[CO:87]) is a single-stranded plant DNA virus, a member of the genus Begomovirus of the family Geminiviridae. BDMV virions are twinned incomplete isosahedra measuring 18 x 30 nm. The viral particle is composed of 110 subunits of coat protein, organized as 22 pentameric capsomers. Each subunit has a molecular mass of approximately 29 kDa. BDMV possesses two DNA components (designated DNA-A and DNA-B), each approximately 2.6 kb in size. The natural and most important host of BDMV is the common bean (Phaseolus vulgaris). Nicotiana benthamiana is often used as an experimental host. Common bean germplasm can be divided into two major gene pools: Andean materials, which are mostly susceptible to BDMV, and Middle American materials, which are mostly resistant to BDMV. The symptom intensity in common bean plants depends on the stage of infection. Early infection of susceptible bean seedlings will result in severe stunting and dwarfing, leaf distortion and mottling or mosaic, as well as chlorotic or yellow spots or blotches. BDMV-infected plants usually abort their flowers or produce severely distorted pods. Late infection of susceptible plants or early infection of moderately resistant genotypes may show a mild mosaic, mottle and crumpling or an irregular distribution of variegated patches. BIOLOGICAL PROPERTIES: As a member of the Begomovirus group, BDMV is transmitted from plant to plant by the whitefly Bemisia tabaci. BDMV is a nonphloem-limited virus and can replicate and move in the epidermal, cortical and phloem cells. As a nonphloem-limited virus, it is sap-transmissible.

Italian Common Bean Landraces: History, Genetic Diversity and Seed Quality

The long tradition of common bean cultivation in Italy has allowed the evolution of many landraces adapted to restricted areas. Nowadays, in response to market demands, old landraces are gradually being replaced by improved cultivars. However, landraces still survive in marginal areas of several Italian regions. Most of them appear severely endangered with risk of extinction due to the advanced age of the farmers and the socio-cultural context where they are cultivated. The present contribution is an overview of the state of the art about the knowledge of Italian common bean germplasm, describing the most important and recent progresses made in its characterization, including genetic diversity and nutritional aspects.

Collection of Common Bean (Phaseolus vulgaris L.) Germplasm in Malaysia and Thailand and Its Potential for Heat Tolerance

Collection of Common Bean (Phaseolus vulgaris L.) Germplasm in Malaysia and Thailand and Its Potential for Heat Tolerance

Selection of a Representative Core Collection from the Chilean Common Bean Germplasm

La raza Chile es un componente importante de la estructura genetica del germoplasma del poroto comun (Phaseolus vulgaris L.). El Instituto de Investigaciones Agropecuarias , INIA, posee alrededor de 1200 accesiones almacenadas en los Bancos activos de Germoplasma en INIA La Platina (Santiago) e INIA Quilamapu (Chillan) y Banco Base en INIA Intihuasi (La Serena). Esta coleccion esta formada por accesiones colectadas a traves de todo el pais. La formacion de una coleccion nucleo se ha planteado como una forma de hacer un uso mas eficiente del germoplasma almacenado en los Bancos de Germoplasma. Los objetivos de este trabajo fueron formar una coleccion nucleo de germoplasma de porotos, y evaluar su representatividad. La estrategia utilizada para formar la coleccion nucleo fue la estratificacion de las accesiones de la coleccion base de acuerdo al acervo genetico y raza, permitiendo que la mayor diversidad genetica estuviera representada en esta nueva coleccion. Los resultados obtenidos indicaron que la coleccion base estaba formada por genotipos pertenecientes a los acervos geneticos Andino y Mesoamericano y a las razas cultivadas Chile, Peru, Nueva Granada, Mesoamerica y Durango. La coleccion nucleo estuvo formada por 246 accesiones, donde se dio mayor representatividad a las accesiones de la raza Chile. La comparacion morfologica, fenologica y agronomica permitio determinar que la diversidad genetica presente en la coleccion base estaba representada adecuadamente en la coleccion nucleo. Esta coleccion nucleo sera de gran utilidad para futuros estudios de caracterizacion de este germoplasma y para seleccionar progenitores para el programa de mejoramiento genetico de frejol.

Registration of High Mineral Common Bean Germplasm Lines NUA35 and NUA56 from the Red‐Mottled Seed Class

NUA35 (Reg. No. GP‐278, PI 657698) and NUA56 (Reg. No. GP‐279, PI 657699), are high seed mineral, red‐mottled common beans (Phaseolus vulgaris L.) developed by the International Center for Tropical Agriculture (CIAT) in Cali, Colombia, and tested with various national agricultural research systems and nongovernmental organizations from Latin America and eastern and southern Africa as part of the Harvest Plus and Agrosalud programs for biofortification. Both germplasm lines were selected from the backcross population [‘CAL96’ × (CAL96 × G14519)] where CAL96 is a commercial cultivar in Colombia and Uganda, and G14519 is a high seed mineral germplasm accession from the CIAT genebank. The seed iron and zinc content of NUA35 and NUA56, along with CAL96 as a check, was determined over 15 sites with varying climate, altitude and soil types in Bolivia, Colombia, Costa Rica, and Guatemala using atomic absorption spectrophotometry. On average, iron content was 18 and 23 mg kg−1 higher for NUA35 and NUA56, respectively than for CAL96; while zinc content was 8 and 7 mg kg−1 higher, respectively. To our knowledge, these are the first germplasm lines to be bred specifically for nutritional quality in common beans.

Genetic diversity, seed size associations and population structure of a core collection of common beans (Phaseolus vulgaris L.)

Cultivated common bean germplasm is especially diverse due to the parallel domestication of two genepools in the Mesoamerican and Andean centers of diversity and introgression between these gene pools. Classification into morphological races has helped to provide a framework for utilization of this cultivated germplasm. Meanwhile, core collections along with molecular markers are useful tools for organizing and analyzing representative sets of these genotypes. In this study, we evaluated 604 accessions from the CIAT core germplasm collection representing wide genetic variability from both primary and secondary centers of diversity with a newly developed, fluorescent microsatellite marker set of 36 genomic and gene-based SSRs to determine molecular diversity and with seed protein analysis to determine phaseolin alleles. The entire collection could be divided into two genepools and five predominant races with the division between the Mesoamerica race and the Durango-Jalisco group showing strong support within the Mesoamerican genepool and the Nueva Granada and Peru races showing less diversity overall and some between-group admixture within the Andean genepool. The Chile race could not be distinguished within the Andean genepool but there was support for the Guatemala race within the Mesoamerican genepool and this race was unique in its high level of diversity and distance from other Mesoamerican races. Based on this population structure, significant associations were found between SSR loci and seed size characteristics, some on the same linkage group as the phaseolin locus, which previously had been associated with seed size, or in other regions of the genome. In conclusion, this study has shown that common bean has very significant population structure that can help guide the construction of genetic crosses that maximize diversity as well as serving as a basis for additional association studies.

Genetics of intra-gene pool and inter-gene pool hybridization for seed traits in common bean ( Phaseolus vulgaris L.) germplasm from Europe

Due to adaptation to new ecological and manmade conditions, the large diversity evolved in the European common bean germplasm is of particular interest for plant breeding. The knowledge of the genetic relationships within and among races and gene pools and their performance per se will provide bean breeders with a starting point in designing crosses using contrasting and complementary parents to broaden the genetic base within the different commercial classes. A genetic study of seed size variation and protein markers in progeny derived from 16 intraracial, interracial and inter-gene pools European common bean populations was conducted. General and specific combining ability (GCA and SCA) values were significant for seed weight, indicating that both additive and nonadditive genetic effects were involved in conditioning seed weight. Interracial populations showed transgressive values due to the accumulation of large-seeded alleles. Genetic variation inside Andean germplasm, and Chile and Peru races in particular, exhibited useful genetic progress in these populations, providing lines with a large seed size, and so, an excellent market potential. The distribution of incompatibility between both gene pools (Mesoamerican and Andean) of the common bean was explored. Inter-gene pool populations provided lower means of inbred segregants than the mid-parent value. Therefore, a good option it would be select for large seed size according to a recurrent or congruity inbred-backcrossing selection programs. Analysis of allele markers frequencies in inter-gene populations showed segregation distortion with a higher than expected frequency of alleles from the Mesoamerican gene pool, many of which were fixed in the F 7 lines. The presence of a great percentage of markers that showed segregation distortion in these populations (87%) indicated that this phenomenon can be amplified by using distance related common bean genotypes. In addition, a high percentage of heterozygotes for the Phs locus (for the seed storage protein phaseolin) was found, which suggest that the Andean homozygous TT could not be expressed in Mesoamerican genetic background due to the action of some form of female specific mechanisms that affected gene exchange between parental germplasm in inter-gene pool populations. The present work provides useful information in the establishment of large seed size germplasm that could have a great deal of interest among breeders and may offer some possibilities to exploit existing variation within and between common bean races.

The bean polygalacturonase-inhibiting protein 2 (PvPGIP2) is highly conserved in common bean (Phaseolus vulgaris L.) germplasm and related species

Polygalacturonase-inhibiting proteins (PGIPs) are extracellular plant protein inhibitors of endo-polygalacturonases (PGs) that belong to the leucine-rich repeat (LRR) protein family. In bean, PGIP is encoded by a small gene family of four members among which Pvpgip2 encodes the most wide-spectrum and efficient inhibitor of fungal PGs. In order to evaluate the sequence polymorphism of Pvpgip2 and its functional significance, we have analyzed a number of wild and cultivated bean (P. vulgaris) accessions of Andean and Mesoamerican origin, and some genotypes from the related species P. coccineus, P. acutifolius, and P. lunatus. Our analyses indicate that the protein encoded by Pvpgip2 is highly conserved in the bean germplasm. The few detected polymorphic sites correspond to synonymous substitutions and only two wild genotypes contain a Pvpgip2 with a single non-synonymous replacement. Sequence comparison showed a slightly larger variation in the related bean species P. coccineus, P. acutifolius, and P. lunatus and confirmed the known phylogenetic relationships with P. vulgaris. The majority of the replacements were within the xxLxLxx region of the leucine rich repeat (LRR) domain and none of them affected residues contributing to structural features. The variant PGIPs were expressed in Nicotiana benthamiana using PVX as vector and their inhibitory activity compared to that of PvPPGIP2. All the variants were able to fully inhibit the four fungal PGs tested with minor differences. Taken together these results support the hypothesis that the overall sequence conservation of PGIP2 and minor variation at specific sites is necessary for high-affinity recognition of different fungal PGs.

Genetic variability of Colletotrichum lindemuthianum isolates from Slovenia and resistance of local Phaseolus vulgaris germplasm

Bean anthracnose caused by Colletotrichum lindemuthianum is one of the most destructive diseases in all bean growing areas. AFLP analysis was used to assess genetic variability and relationships among C. lindemuthianum isolates from Slovenia. Isolates were obtained from different common bean growing regions in Slovenia and have previously been characterized as races 23, 55, 103 and 131. AFLP clustering revealed two main groups that did not clearly correspond to race classification based on pathogenicity towards differential common bean cultivars. Local common bean germplasm as well as the set of 12 international differential bean cultivars were evaluated for resistance against the four C. lindemuth-ianum races that occur in Slovenia. None of the 26 local common bean landraces and cultivars was resistant to all four races; however, six genotypes reacted as moderately resistant. Considerably higher level of resistance was recorded among differential common bean cultivars, particularly those derived from the Mesoamerican germplasm. Introgression of some major anthracnose resistance genes from the Mesoamerican germplasm is therefore recommended to develop resistant common bean cultivars for our production system.

Potencial de aumento do teor de ferro em grãos de feijão por melhoramento genético

O desenvolvimento de germoplasma de feijão com maior teor de ferro nos grãos é uma alternativa para minimizar os problemas da deficiência desse mineral na dieta. Para tanto, é preciso verificar se ocorre efeito materno para o teor de ferro e conhecer a herança desse caráter, objetivos desse trabalho. As gerações F1, F1 recíproco, F2, F2 recíproco, F3, F3 recíproco, retrocruzamento 1 e retrocruzamento 2 foram obtidas para os cruzamentos entre Minuano x Diamante Negro e Diamante Negro x IAPAR 44. O teor de ferro foi determinado por meio de digestão nítrica-perclórica e leitura em espectrofotômetro de absorção atômica. Variabilidade genética para o teor de ferro nos grãos foi obtida nos diferentes cruzamentos e constatou-se efeito materno na expressão do teor de ferro em feijão. Estimativas de herdabilidade em sentido amplo de 76,36% e em sentido restrito de 50,60% foram observadas, a partir do cruzamento entre Minuano x Diamante Negro. Ganho por seleção de 11,14% foi obtido, comprovando que é possível aumentar o teor de ferro em grãos de feijão por meio de melhoramento genético. A seleção realizada em gerações precoces poderá ser efetiva no desenvolvimento de germoplasma de feijão com alto teor de ferro nos grãos.

Efeitos gênicos do teor de cálcio em grãos de feijão

O objetivo deste trabalho foi investigar a existência de efeito materno para o teor de cálcio em grãos de feijão e obter estimativas de herdabilidade e de efeitos gênicos para seleção em gerações precoces. Os cruzamentos controlados foram realizados entre as cultivares "Pérola" x "TPS Bonito" e "TPS Bonito" x "BRS Expedito". As gerações F1, F1 recíproco, F2, F2 recíproco, F3, F3 recíproco, RCP1 e RCP2 foram obtidas para cada combinação híbrida. O teor de cálcio foi determinado por meio de digestão nítrico-perclórica e leitura em espectrofotômetro de absorção atômica. Variabilidade genética para o teor de cálcio nos grãos foi constatada nos diferentes cruzamentos, com maior influência dos efeitos gênicos aditivos, além de expressão de efeito materno. Estimativas de herdabilidade, em sentido amplo, de 66,75% e de 74,65% e, em sentido restrito, de 47,00% e 63,61%, foram obtidas para os cruzamentos "Pérola" x "TPS Bonito" e "TPS Bonito" x "BRS Expedito", respectivamente. A seleção realizada em gerações precoces poderá ser efetiva no desenvolvimento de germoplasma de feijão com alto teor de cálcio nos grãos.

Registration of Common Bacterial Blight, Rust and Bean Common Mosaic Resistant Great Northern Common Bean Germplasm Line ABC‐Weihing

Great northern common bean (Phaseolus vulgaris L.) germplasm line ABC‐Weihing (Reg. No. GP‐246, PI 647964) was developed by the University of Nebraska Agricultural Research Division in cooperation with USDA‐ARS and released in 2006. This line, tested as NE1‐05‐4, was bred specifically for enhanced resistance to common bacterial blight (CBB), a major seed borne disease of common bean caused by the bacterium Xanthomonas campestris pv. phaseoli (Smith) Dye (Xcp). ABC‐Weihing is a great northern BC5F3:6 line obtained from five backcrosses (‘Weihing’*5//‘Chase’/XAN 159). The first cross was made in spring 1997. Only BCnF1 plants resistant to Xcp isolates Dominican Republic DR‐7 and Nebraska SC4A, as determined by multiple needle leaf inoculation tests in the greenhouse, were used for successive backcrossing. In addition to phenotypic selection for CBB resistance, marker‐assisted selection for the resistant QTL‐linked marker SU91 was conducted in the BC1F1, BC2F1, and ABC‐Weihing. When inoculated with Nebraska Xcp strains in the field, ABC‐Weihing exhibited resistance in both 2005 and 2006. ABC‐Weihing has Ur‐3 and Ur‐6 genes for resistance to common bean rust and carries the single dominant hypersensitive I gene that provides resistance to all non‐necrotic strains of the Bean common mosaic virus (BCMV). ABC‐Weihing has bright white seed, blooms 45 d after planting, and is a midseason bean maturing 92 d after planting.

Selecting Common Bean with Genes of Different Evolutionary Origins for Resistance to Xanthomonas campestris pv. phaseoli

Common bacterial blight (CBB) is an important seed‐borne disease of common bean (Phaseolus vulgaris L.). Low levels of resistance occur in the common and scarlet runner bean (Phaseolus coccineus L.), with higher levels available in the tepary bean (Phaseolus acutifolius A. Gray). Germplasm lines with CBB resistance separately from each of the three Phaseolus species and pyramided resistance are available. The objectives of this study were to: (i) determine the main and interaction effects of two isolates of Xanthomonas campestris pv. phaseoli (Xcp), one from Colorado and one from Wisconsin, and their inoculum densities with CBB resistance from the three species separately and pyramided; and (ii) identify the most useful germplasm for breeding for resistance. Thirty‐one genotypes were evaluated at 14 and 21 d after inoculation (DAI) using two inoculum densities in 2005 and three in 2006 of each of the two Xcp isolates. Large differences in response to Colorado and Wisconsin Xcp isolates, densities, and evaluation time were observed. The resistance derived from the three species separately was not effective against the aggressive Wisconsin Xcp isolate at higher densities ≥108, especially at 21 DAI. Resistance pyramided with the tepary bean was the most effective. No crossover interactions were observed between the 31 common bean germplasm sources and the two Xcp isolates at any density and evaluation date. Use of only pyramided resistance for breeding is advised.

Differential Response of Common Bean Cultivars to Phakopsora pachyrhizi

Soybean rust (Phakopsora pachyrhizi) has been reported on common bean (Phaseolus vulgaris) in Asia, South Africa, and the United States. However, there is little information on the interaction of individual isolates of Phakopsora pachyrhizi with common bean germplasm. A set of 16 common bean cultivars with known genes for resistance to Uromyces appendiculatus, the causal agent of common bean rust, three soybean accessions that were sources of the single gene resistance to P. pachyrhizi, and the moderately susceptible soybean 'Ina' were evaluated using seedlings inoculated with six isolates of P. pachyrhizi. Among the common bean cultivars, Aurora, Compuesto Negro Chimaltenango, and Pinto 114, were the most resistant to all six P. pachyrhizi isolates, with lower severity, less sporulation, and consistent reddish-brown (RB) lesions associated with resistance in soybean. A differential response was observed among the common bean cultivars, with a cultivar-isolate interaction for both severity and sporulation levels, as well as the presence or absence of the RB lesion type. This differential response was independent of the known genes that condition resistance to U. appendiculatus, suggesting that resistance to P. pachyrhizi was independent of resistance to U. appendiculatus.

Genetic diversity in common bean accessions evaluated by means of morpho-agronomical and RAPD data

Germplasm banks store genotype samples, improved varieties, landraces and wild species, all generically denominated accessions. The importance of characterizing germplasm banks is based on the identification and knowledge of relevant traits for genetic improvement and ex situ germplasm conservation. Thus, the present study had as aim the evaluation of the genetic diversity among 220 accessions of a Brazilian common bean germplasm bank of the "Instituto Agronômico de Campinas" (IAC) by means of 23 morpho-agronomical descriptors and 19 RAPD loci. These accessions correspond to genotypes from the Andean and Middle American gene pool as well as from cultivars derived from common bean improvement programs. The Middle American accessions and the improved cultivars were clustered into one group, distinct from the one formed by the Andean accessions. In relation to the molecular data, 47% of the genetic similarity was detected among the Middle American accessions, and similar results were observed for the improved cultivars (50%). The Andean accessions revealed 60% of genetic similarity. The cluster constituted by the improved cultivars and the Middle American genotypes differed, basically, in tegument color. Both molecular and morpho-agronomical data sets were equally effective to quantify and organize the genetic diversity of common bean accessions. This information may be useful to direct crosses and for the proper organization of the IAC germplasm bank.

Registration of Common Bacterial Blight Resistant White Kidney Bean Germplasm Line USWK‐CBB‐17

Registration of Common Bacterial Blight Resistant White Kidney Bean Germplasm Line USWK‐CBB‐17

Temporal changes in genetic diversity of common bean (Phaseolus vulgaris L.) accessions cultivated between 1800 and 2000

Fourteen microsatellite markers were used to describe genetic diversity in a sample of 128 common bean (Phaseolus vulgaris L.) accessions cultivated within the territory of Slovenia and its nearby regions between 1800 and 2000. The accessions were grouped into three periods, Period I comprising accessions from the beginning of the 19th century, while the other two periods included accessions from the middle (Period II) and the end of the 20th century (Period III). Seven control accessions of known Mesoamerican and Andean origin were also included in the study. A total of 130 alleles were generated. Allelic richness, in terms of number of alleles per locus, was 6.07 for Period I, 6.71 for Period II and 6.07 for Period III. In the UPGMA dendrogram, all studied accessions were intermixed in three main clusters, indicating that the diversity in the time periods overlapped. Two clusters consisted of accessions of Andean and Mesoamerican origin, while the third represents additional variation, which existed in this area already 200 years ago. The analysis of molecular variance showed that a great part of genetic diversity has been preserved till today, confirming the results of cluster analysis. The calculation of number of alleles per locus revealed no significant quantitative change in genetic diversity over the last 200 years of common bean cultivation. However, the calculation of genetic distances indicated slight qualitative shifts in genetic diversity of common bean germplasm over time, while the calculations of allelic frequency variation and polymorphic information content revealed recent decline of some alleles' frequencies. These findings should stress the need for establishing an appropriate strategy of genetic resources management.

Genetic Diversity and Origin of Slovene Common Bean (Phaseolus vulgaris L.) Germplasm as Revealed by AFLP Markers and Phaseolin Analysis

There is a long tradition of common bean cultivation in Slovenia, which has resulted in the development of numerous landraces in addition to newly established cultivars. The genetic diversity of 100 accessions from the Genebank of the Agricultural Institute of Slovenia (AIS) were evaluated with amplified fragment length polymorphism (AFLP) markers and phaseolin seed protein. Twenty-seven standard accessions of known Mesoamerican and Andean origin, 10 wild Phaseolus vulgaris accessions and two related species, P. coccineus L. and P. lunatus L., were also included. Ten AFLP primer combinations produced 303 polymorphic bands, indicating a relatively high level of genetic diversity. Based on the marker data, unweighted pair group method with arithmethic mean (UPGMA) analysis and principal coordinate analysis (PCoA) all P. vulgaris accessions were separated into three well-defined groups. Two groups consisted of accessions of Mesoamerican and Andean origin, while the third was comprised of only four wild P. vulgaris accessions. A set of Slovene accessions formed a well-defined sub-group within the Andean cluster, showing their unique genetic structure. These data were supported by phaseolin analysis, which also revealed additional variants of “C” and “T” phaseolin types. The results are in agreement with previous findings concerning diversification of common bean germplasm introduced in Europe.

Fuentes de resistencia a la antracnosis y la mancha angular en frijol común para Costa Rica.

The objective of this study was to select sources of resistance to angular leaf spot and anthracnose from a diverse group of germplasm with known resistance to these diseases and other abiotic and biotic factors. Atotal of 173 common beans that included 46 landraces and 127 breeding lines were evaluated at two locations (Estación Experimental Fabio Baudrit Moreno and Sub-Estación Experimental Fraijanes, both of Universidad de Costa Rica) in 1996 and 1997. A mixture of four races (races 9, 10, 547, and 1024 of maximum virulence and coverage in Costa Rica) of the anthracnose pathogen was used to inoculate four times. Because of high natural incidence of angular leaf spot, inoculation was not necessary. Twenty-one landraces and 13 breeding lines were resistant (disease score of 3 or less) to antracnose. Only five landraces (G 12529, G 14934, G 19428, G 19696, and G 19831), one improved cultivar (ICA Tundama), and a breeding line UCR 55 had intermediate reaction (disease score between 4 and 6). Thus, for angular leaf spot evaluation of a much broader range of germplasm of common bean and other related species is suggested.

Identification of common bean (Phaseolus vulgaris) duplicates using agromorphological and molecular data

We used agromorphological and random amplified polymorphic DNA (RAPD) molecular marker data to identify duplicate common bean (Phaseolus vulgaris L. Fabaceae) accessions in the Common Bean Germplasm Bank of the Agronomical Institute - IAC (Banco de Germoplasma de feijoeiro do Instituto Agronomico de Campinas (IAC), SP, Brazil). A total of 116 accessions with the same names and similar agromorphological traits was analyzed. The divergence between the accessions was initially evaluated by means of the agromorphological descriptors using single linkage clustering, from the Euclidean distance. Multivariate analysis identified four duplicate accessions (Carioca Lustroso, Bico de Ouro, Jamapa and Preto), with 17 other same-name accessions being suspected duplicates due to their low divergence levels. Accessions with low genetic distance values (indicating that they were duplicates) were further compared using RAPD markers which confirmed the results of the multivariate analyses in relation to the four duplicate accessions, although only two of the other 17 suspect accessions were confirmed to be duplicates, in this case of accessions IAPAR 57 and Sacavem. These results show that the combined use of agromorphological and molecular information allowed a better characterization of the acessions in the common bean Germplasm Bank.