Towards Heat Tolerant Runner Bean (Phaseolus coccineus L.) by Utilizing Plant Genetic Resources

Abstract

Climate change and its extreme heat waves affect agricultural productivity worldwide. In the cultivation of beans, heat stress during the reproductive phase may lead to complete crop failures, as recently was documented for runner bean (Phaseolus coccineus L.) in Austria. Developing better adapted varieties utilizing plant genetic resources is of utmost importance in such conditions. Our study aimed at identifying heat tolerant accessions and developing associated genetic markers for their application in marker assisted selection. For this, we assessed the genetic and phenotypic characteristics of 113 runner bean genotypes (101 of Austrian origin) grown in the glasshouse under heat stress conditions during two years. In particular three accessions showed a higher yield than the reference variety Bonela under heat stress in both years. The phenotypic data complemented with genetic data based on 1190 SNPs revealed high performing pure genotypes that may serve as good candidates to be included in breeding programs. In addition, the genome-wide association analysis resulted in 18 high quality SNPs that were subsequently used for the calculation of an estimated heat tolerance using the MassARRAY® system. Overall, our study represents first steps towards breeding heat tolerant runner bean to withstand global warming.