Attempts at Interspecific Hybridization Between Phaseolus vulgaris L. and P. acutifolius A. Gray‐Using Embryo Rescue

Abstract

AbstractAttempts at interspecific hybridization were made between Phaseolus vulgaris (common bean) and P. acutifolius (tepary bean) using a new pollination method and embryo rescue. The success of interspecific hybridization depended upon the pollination technique, the species and individual genotypes used as female and male parents, and the growth conditions. A high hybridization efficiency was achieved when P. vulgaris was used as female parent. When pods were left on the maternal plants hybrid seeds were obtained which developed into abnormal seedlings. These died at an early stage of growth. Hybrid plants were grown to maturity following embryo rescue, but all showed different developmental abnormalities. The growth of these was determinate like the female parent, P. vulgaris, but leaf morphology was closer to the male parent, P. acutifolius. The utilization of P. acutifolius germplasm for the improvement of common bean remains limited, and further studies are needed to develop promising embryo rescue protocols in such wide crossing programmes.