Discrimination of common bean cultivars using multiplexed microsatellite markers

Abstract

ABSTRACT. Analysis of DNA polymorphisms allows for the genetic identification and precise discrimination of species with a narrow genetic base such as common bean. The primary objectives of the present study were to molecularly characterize commercial common bean varieties developed at various research institutions using microsatellite markers and to determine the degree of genetic diversity among the bean varieties analyzed. Fifty cultivars representing 12 grain classes and 64 genitors, i.e., accessions used to develop these cultivars, were characterized. Based on an analysis of 24 simple sequence repeats, the estimates for the average number of alleles and genetic diversity were 8.29 and 0.646, respectively. The combined probability of identity was estimated at 7.05 x 10 -17 , indicating a high individual discriminatory power. Thirtytwo percent of the cultivars exhibited heterogeneity for multiple loci that reflected either homozygosity for different alleles of a given locus in different individuals or heterozygosity for the locus. The average 1964-1978 (2014) Molecular characterization of cultivated common bean genetic diversity for the groups of cultivars and genitors was 0.605 and 0.660, respectively, with no genetic differentiation (F ST ) between these groups. Although similar estimates of expected heterozygosity were observed when the cultivars were grouped by release date, a greater number of private alleles was observed in the most recent cultivars. The genetic differentiation among cultivars originating from different institutions was not different from zero (F ST = 0.01). The molecular profile database derived from these analyses may increase the statistical power of genetic estimates and may be incorporated into breeding programs for common bean. Furthermore, the profiles obtained for the different cultivars may be used as molecular descriptors to complement traditional descriptors used in distinctiveness, uniformity and stability tests, thereby improving the traceability of samples and their derivatives and helping to protect the intellectual property rights of breeders.

Genetic divergence of common bean cultivars

“…There was variation of 2-4 alleles per locus, with the primers PvBR25 and ATA6 being the most informative (Table 4). Cardoso et al (2013Cardoso et al ( , 2014 found a mean number of alleles per locus greater than that seen in the present study. In 2013, the authors evaluated the genetic divergence of 172 common bean lines and cultivars making up five VCU trials conducted by the genetic breeding program of Embrapa Arroz e Feijão using 30 pairs of polymorphic primers.…”

Application of microsatellite markers to confirm controlled crosses and assess genetic identity in common bean

“…The panel of 24 microsatellite loci used in this study is being routinely used at different stages of the common bean breeding program conducted by Embrapa and partners. In addition to the confirmation of controlled crosses and the detection of genetic identity of genotypes, other microsatellite marker applications include studies of genetic diversity among parents and elite lines, monitoring of allelic diversity and genetic representation of parents in breeding populations obtained by backcrosses and recurrent selection, aside from the control of genetic purity during the seed production process (Batista et al 2014, Cardoso et al 2014. It is worth mentioning that this molecular tool is available for immediate adoption and use by other common bean breeding programs in Brazil and worldwide.…”

Selection of common bean (Phaseolus vulgaris L.) genotypes using a genotype plus genotype x environment interaction biplot

“…However, this yield is low considering the crop's potential, which can reach 4.5 Mg/ha. This legume is an important source of protein for the Brazilian population, particularly for low-income groups (Cardoso et al, 2014;Pereira et al, 2014). Therefore, it is necessary to select highly productive genotypes that are adapted to the soil and climatic conditions of particular locations, which will increase the average national yield.…”