Frontiers in Plant Science (Jul 2015)
Identification of novel drought-tolerant-associated SNPs in common bean (Phaseolus vulgaris)
Abstract
Common bean (Phaseolus vulgaris L.) is a leguminous in high demand for human nutrition and a veryimportant agricultural product. Production of common bean is constrained by environmental stressessuch as drought. Although conventional plant selection has been used to increase production yield andstress tolerance, drought tolerance selection based on phenotype is complicated by associatedphysiological, anatomical, cellular, biochemical and molecular changes. These changes are modulatedby differential gene expression. A common method to identify genes associated with phenotypes ofinterest is the characterization of Single Nucleotide Polymorphims (SNPs) to link them to specificfunctions.In this work, we selected two drought-tolerant parental lines from Mesoamerica, Pinto Villa and PintoSaltillo. The parental lines were used to generate a population of 282 families (F 3:5 ) and characterizedby 169 SNPs . We associated the segregation of the molecular markers in our population withphenotypes including flowering time, physiological maturity, reproductive period, plant, seed and totalbiomass, reuse index, seed yield, weight of 100 seeds and harvest index in three cultivation cycles.We observed 83 SNPs with significant association (p < 0.0003 after Bonferroni correction) with ourquantified phenotypes. Phenotypes most associated were days to flowering and seed biomass with 58and 44 associated SNPs respectively. Thirty-seven out of the 83 SNPs were annotated to a gene with apotential function related to drought tolerance or relevant molecular/biochemical functions. Some SNPssuch as SNP28 and SNP128 are related to starch biosynthesis, a common osmotic protector; andSNP18 is related to proline biosynthesis, another well-known osmotic protector.
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