Adaptation of common bean lines to high temperature conditions: genotypic differences in phenological and agronomic performance

The common bean is the most important legume for human consumption and is grown in areas under conditions of varied rainfall and temperature that limit its yield. The objective of the present study was to identify genotypic differences in adaptation of 91 bean genotypes to high temperature under environmental conditions of a tropical dry forest ecosystem. We quantified differences among genotypes in terms of phenology, dry matter partitioning indices and grain yield. Common bean lines were derived from interspecific and intraspecific crosses among Phaseolus species of P. vulgaris, P. acutifolius, P. coccineus and P. dumosus. We identified three germplasm accessions of P. acutifolius (G 40001, G 40027, G 40141); two lines from the cross of P. vulgaris × P. acutifolius (INB 837, SIN 524); two lines from the cross of P. vulgaris × P. acutifolius × P. coccineus (SEF 14, SEF 42) and eight lines of P. vulgaris (BFS 10, SEN 46, SEN 48, SEN 70, SMN 99, SMC 140, SMR 139-1G, AMADEUS-EAP-9510-77) that are better adapted to higher temperature stress conditions, evidencing the significant contribution of P. acutifolius to heat tolerance derived from interspecific crosses in common beans. We also found a few Andean lines of growth habit I (SAP 1, SAP 1-15, SAP 1-16, G 122, SAB 618, DAB 525) with superior level of adaptation to heat stress. The superior performance of all these above identified genotypes under higher temperature conditions was attributed to early maturity, high pollen viability and greater ability to partition dry matter to reproductive growth together with greater grain filling.