Mapping of an andean gene for anthracnose resistance (Co-13) in common bean (Phaseolus vulgaris L.) Jalo Listras Pretas landrace

Abstract The common bean (Phaseolus vulgaris L.) andean Jalo Listras Pretas (JLP) landrace is an important source of resistance to anthracnose, which is a widespread disease caused by Colletotrichum lindemuthianum fungus. This common bean landrace carries Co-13 gene, one of the nine ones identified andean anthracnose resistance genes. The present study set out to identify molecular markers associated with Co-13 by evaluating the segregation patterns of 65 molecular markers, in a F 2 population derived from a cross between JLP (resistant to race 73 of C. lindemuthianum) and Cornell 49-242 (susceptible to race 73 of C. lindemuthianum) cultivars. Bulked segregant analysis was performed to identify which of these molecular markers was linked to Co-13 in JLP. Among the analyzed molecular markers, OV20 680 marker displayed a heteromorphic band of 680 bp linked to Co-13 resistant gene in coupling phase. Genotyping of the OV20 680 marker in F 2 population revealed a recombination of 1.7%, indicating a tight linkage between the OV20 680 marker and disease resistance gene (Co-13). In the recombinant inbred population BAT93/Jalo EEP558, OV20 680 segregated according to a 1:1 ratio and mapped on linkage group Pv03 at a distance of 1.8 cM from the Co-13 locus. Jalo Listras Pretas has shown to be an important source of resistance to anthracnose, possessing a new gene that should be valuable in breeding for anthracnose resistance in common bean. Identifying molecular markers linked to andean resistance genes may facilitate the development of cultivars with broad-based resistance to anthracnose by streamlining the process of combining andean and mesoamerican resistance genes

Genetic diversity and population structure of sweet cassava using simple sequence repeat (SSR) molecular markers

The objective of this study was to evaluate the population structure and genetic diversity among 66 sweet cassava (Manihot esculenta Crantz) traditional accessions collected in Maringa, Parana, Brazil, using microsatellite molecular markers. Population structure was analyzed by means of genetic distances and probabilistic models; allelic frequencies were used in order to assess the genetic diversity indexes (Ht , Ho, PIC, % polymorphism and number of alleles) for each locus studied. All evaluated loci were polymorphic and the average was highly heterozygote. The number of alleles per locus was low, suggesting that restrict genetic base is a consequence of accession exchange and a reduced number of ancestors in the population. The polymorphic information content (PIC) values showed considerable genetic diversity with a mean value of 0.5076 and peak of 0.5707 for locus GA140. The microsatellites markers revealed a wide genetic variability among the traditional accessions evaluated. Moreover, the sweet cassava populations were separated in two groups using two analytical methods (probabilistic and genetic distances). The most divergent accessions were BGM 17, BGM 20, BGM 51 and BGM 95. On the other hand, the most similar accessions were BGM 25, BGM 33, BGM 37, BGM 59 and BGM 214. Hybrid combinations formed by the most divergent combinations, especially between BGM 51 × BGM 296, BGM 95 × BGM 222 and BGM 20 × BGM 12, are the most promising ones for future sweet cassava breeding programsFil: Costa, Tiago Ribeiro Da. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Vidigal Filho, Pedro Soares. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Gonçalves Vidigal, Maria Celeste. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Galván, Marta Zulema. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Salta-Jujuy. Estación Experimental Agropecuaria Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Fisiología Vegetal; ArgentinaFil: Lacanallo, Giselly Figueiredo. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Silva, Luciano Ivano Da . Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Kvitschal, Marcus Vinicius. Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina; Brasi

Genetic diversity and population structure of cotton (Gossypium hirsutum L. race latifolium H.) using microsatellite markers

Cotton (Gossypium spp.) is the world?s leading natural fiber crop and is cultivated in diverse temperate and tropical areas. The proper use of cotton genetic resources allows breeders to identify and select superior parents for breeding programs. In this sense, molecular markers are important tools for polymorphism identification in genetic diversity analyses. The objective of this study was to evaluate genetic diversity and population structure in tetraploid cotton (Gossypium hirsutum L. race latifolium H.) by means of microsatellite markers. 43 cultivars and inbred lines from Africa, United States and Brazil were analyzed. From a total of 33 SSRs markers, 15 markers revealed 104 polymorphic SSR alleles. Four groups were identified applying different methods (the probabilistic method, principal coordinates analysis and neighbor joining tree). American cultivars and inbred lines were included in group I; African cultivars in group II; and Brazilian cultivars in groups II, III and IV. The FST index indicated high genetic variability among the cultivars and inbred lines studied. In general, American cultivars were the most divergent in relation to African and Brazilian ones. The dissimilarity index ranged from 0.06 to 0.90 and the lowest genetic divergence was observed between TAMCOT22 and TAM96WD-69s(L). Combination of American cultivars and inbred lines with African and Brazilian cultivars is recommended to obtain superior transgressive segregants in order to improve yield in cotton breeding programs.Fil: Domingos Moiana, Leonel. No especifíca;Fil: Soares Vidigal Filho, Pedro. Universidade Estadual de Maringá; BrasilFil: Gonçalves Vidigal, Maria Celeste. Universidade Estadual de Maringá; BrasilFil: Figueiredo Lacanallo, Giselly. Universidade Estadual de Maringá; BrasilFil: Galván, Marta Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: de Carvalho, Luiz Paulo. No especifíca;Fil: Maleia, Manuel Pedro. No especifíca;Fil: Maritza Pacheco, Cynthia. Universidade Estadual de Maringá; BrasilFil: Ribeiro, Tiago. Universidade Estadual de Maringá; BrasilFil: Zeni Neto, Hugo. Universidade Estadual de Maringá; BrasilFil: Kelly Coimbra, Gislayne. Universidade Estadual de Maringá; Brasi

Review: Genetic diversity and population structure of cotton (Gossypium hirsutum L. race latifolium H.) using microsatellite markers

Cotton (Gossypium spp.) is the world’s leading natural fiber crop and is cultivated in diverse temperate and tropical areas. In this sense, molecular markers are important tools for polymorphism identification in genetic diversity analyses. The objective of this study was to evaluate genetic diversity and population structure in tetraploid cotton (Gossypium hirsutum L. race latifolium H.) by means of microsatellite markers. 43 cultivars and inbred lines from Africa, United States and Brazil were analyzed. From a total of 33 SSRs markers, 15 markers revealed 104 polymorphic SSR alleles. Four groups were identified applying different methods (the probabilistic method, Principal Coordinates Analysis and Neighbor Joining tree). American cultivars and inbred lines were included in group I; African cultivars in group II; and Brazilian cultivars in groups II, III and IV. The FST index indicated high genetic variability among the cultivars and inbred lines studied. In general, American cultivars were the most divergent compared to African and Brazilian ones. The dissimilarity index ranged from 0.06 to 0.90 and the lowest genetic divergence was observed between TAMCOT22 and TAM96WD-69s(L). Combination of American cultivars and inbred lines with African and Brazilian cultivars is recommended for obtaining superior segregant in order to improve yield.Key words: Dissimilarity index, Gossypium hirsutum L., polymorphism, SSRs markers

Genetics and mapping of a new anthracnose resistance locus in Andean common bean Paloma

Background: The Andean cultivar Paloma is resistant to Mesoamerican and Andean races of Colletotrichum lindemuthianum, the fungal pathogen that causes the destructive anthracnose disease in common bean. Remarkably, Paloma is resistant to Mesoamerican races 2047 and 3481, which are among the most virulent races of the anthracnose pathogen. Most genes conferring anthracnose resistance in common bean are overcome by these races. The genetic mapping and the relationship between the resistant Co-Pa gene of Paloma and previously characterized anthracnose resistance genes can be a great contribution for breeding programs. Results: The inheritance of resistance studies for Paloma was performed in F2 population from the cross Paloma (resistant) × Cornell 49–242 (susceptible) inoculated with race 2047, and in F2 and F2:3 generations from the cross Paloma (resistant) × PI 207262 (susceptible) inoculated with race 3481. The results of these studies demonstrated that a single dominant gene confers the resistance in Paloma. Allelism tests performed with multiple races of C. lindemuthianum showed that the resistance gene in Paloma, provisionally named Co-Pa, is independent from the anthracnose resistance genes Co-1, Co-2, Co-3, Co-4, Co-5, Co-6, Co-12, Co-13, Co-14, Co-15 and Co-16. Bulk segregant analysis using the SNP chip BARCBean6K_3 positioned the approximate location of Co-Pa in the lower arm of chromosome Pv01. Further mapping analysis located the Co-Pa gene at a 390 kb region of Pv01 flanked by SNP markers SS82 and SS83 at a distance of 1.3 and 2.1 cM, respectively. Conclusions: The results presented here showed that Paloma cultivar has a new dominant gene conferring resistance to anthracnose, which is independent from those genes previously described. The linkage between the Co-Pa gene and the SS82 and SS83 SNP markers will be extremely important for marker-assisted introgression of the gene into elite cultivars in order to enhance resistance.EEA SaltaFil: Castro, Sandra Aparecida de Lima. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Gonçalves-Vidigal, Maria Celeste. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Gilio, Thiago Alexandre Santana. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Lacanallo, Giselly Figueiredo. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Valentini, Giseli. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Martins, Vanusa da Silva Ramos. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Qijian, Song. United States Department of Agriculture. Agricultural Research Service. Soybean Genomics and Improvement Laboratory; Estados UnidosFil: Galvan, Marta Zulema. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Hurtado-Gonzales, Oscar P. United States Department of Agriculture. Agricultural Research Service. Soybean Genomics and Improvement Laboratory; Estados UnidosFil: Pastor-Corrales, Marcial Antonio. United States Department of Agriculture. Agricultural Research Service. Soybean Genomics and Improvement Laboratory; Estados Unido

Genetic divergence in germplasm of common bean in Paraná State, Brazil

O presente trabalho teve como objetivo avaliar a divergência genética entre 63 cultivares crioulas de feijão comum (Phaseolus vulgaris L.) coletadas no Estado do Paraná no período de 2001 a 2002. O experimento foi conduzido em área experimental localizada no Município de Toledo, PR, no ano de 2002. O delineamento experimental utilizado foi o de blocos casualizados com três repetições. Os dados obtidos em cada característica foram submetidos à análise de variância considerando-se o efeito da cultivar como fixo. A análise multivariada foi usada para avaliar a divergência genética entre os genótipos utilizando-se as Variáveis Canônicas e o método de agrupamento com base na Distância Generalizada de Mahalanobis ( 2 ii' D ). As cultivares mais divergentes foram Carioca Pitoco e Jalo Vermelho e as mais similares foram Carioca Pitoco e Carioca. Esses resultados evidenciaram a existência de variabilidade genética nas cultivares de feijão utilizadas pelos agricultores e os que métodos de análises multivariadas demonstraram eficiência em detectá-la separando em grupos diferentes as cultivares Carioca e Jalo. As cultivares Carnaval (33), Carioca Pitoco (16), Pérola (14) e Carnaval (27), por apresentarem maiores produtividades e serem mais divergentes, são indicadas para gerar populações em programas de seleção interpopulacional.The present work had objective to evaluate the genetic divergence among 63 traditional cultivars of the common bean (Phaseolus vulgaris L.) collected in Paraná state in the period 2001-2002. The experiment was carried out in an experimental area in 2002 in the county Toledo, PR. The experimental design was a randomized block with three replications. The Multivariate was used to evaluate the divergence among the genotypes, utilizing the Canonic Variable analysis and clustering, based on the Generalized Mahalanobis Distance ( 2 ii' D ) for the quantitative variables. The results demonstrated that the most divergent cultivars were Carioca Pitoco and Jalo vermelho, whereas the most similar were Carioca Pitoco and Carioca. These results point out the existence of genetic variability in common bean cultivars used by farmers, and multivariate analysis methods demonstrated efficiency to detect them, separating the cultivars Carioca and Jalo in different groups. Therefore, in order to compose the interpopulation selection programs the Carnaval (33), Carioca Pitoco (16), Pérola (14) and Carnaval (27) cultivars are recommend because they are the most divergent ones and possess one of the best averages in productivity

Genetic diversity and population structure of sweet cassava using simple sequence repeat (SSR) molecular markers

The objective of this study was to evaluate the population structure and genetic diversity among 66 sweet cassava (Manihot esculenta Crantz) traditional accessions collected in Maringa, Parana, Brazil, using microsatellite molecular markers. Population structure was analyzed by means of genetic distances and probabilistic models; allelic frequencies were used in order to assess the genetic diversity indexes (Ht , Ho, PIC, % polymorphism and number of alleles) for each locus studied. All evaluated loci were polymorphic and the average was highly heterozygote. The number of alleles per locus was low, suggesting that restrict genetic base is a consequence of accession exchange and a reduced number of ancestors in the population. The polymorphic information content (PIC) values showed considerable genetic diversity with a mean value of 0.5076 and peak of 0.5707 for locus GA140. The microsatellites markers revealed a wide genetic variability among the traditional accessions evaluated. Moreover, the sweet cassava populations were separated in two groups using two analytical methods (probabilistic and genetic distances). The most divergent accessions were BGM 17, BGM 20, BGM 51 and BGM 95. On the other hand, the most similar accessions were BGM 25, BGM 33, BGM 37, BGM 59 and BGM 214. Hybrid combinations formed by the most divergent combinations, especially between BGM 51 × BGM 296, BGM 95 × BGM 222 and BGM 20 × BGM 12, are the most promising ones for future sweet cassava breeding programsFil: Costa, Tiago Ribeiro Da. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Vidigal Filho, Pedro Soares. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Gonçalves Vidigal, Maria Celeste. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Galván, Marta Zulema. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Salta-Jujuy. Estación Experimental Agropecuaria Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Fisiología Vegetal; ArgentinaFil: Lacanallo, Giselly Figueiredo. Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Silva, Luciano Ivano Da . Universidade Estadual de Maringá. Departamento de Agronomia; BrasilFil: Kvitschal, Marcus Vinicius. Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina; Brasi