Introgression of anthracnose resistance into the background of locally adapted common bean landraces

Abstract

Adequate knowledge, access and introgression of genetic diversity available in cultivated and wild relatives are pre-requisites for widening the genetic base of cultivars to sustain genetic improvement. An attempt was made to screen anthracnose resistance in 33 indigenous and exotic accessions of common bean (Phaseolus vulgaris L.) belonging to primary, secondary, tertiary and quaternary gene pools including three popular and widely cultivated landraces of North-Western Indian Himalayas. The cultivated and wild species of common bean were introgressed into the backgrounds of landraces, which resulted in the development of 22 crosses comprising 6 each of intra and interspecific crosses with P. vulgaris and P. coccineus, 3 with P. acutifolius, 2 with P. lunatus and 5 backcrosses. The hybridity of these crosses was confirmed using morphological and molecular markers. The interspecific crosses of P. vulgaris × P. coccineus, P. vulgaris × P. acutifolius and P. vulgaris × P. lunatus were attempted for the first time in India using in-vitro approaches. Further hybrid plants were grown to maturity following embryo rescue protocol, but all showed different developmental abnormalities. The overall establishment of successful hybrids and their complete development was the maximum in cross of Bhaderwah Local × Poonch Local (18.28%) and the minimum in Bhaderwah Local × IC258276 and Bhaderwah Local × IC328372 (0.5%). The results of the present study revealed that wild relatives of common bean viz. P. coccineus, P. acutifolius and P. lunatus are an excellent source of resistance against anthracnose, which can be exploited for diversification of cultivated gene pool. These resistant genetic resources could also be shared among common bean researchers in the country or elsewhere under Standard Material Transfer Agreement for strengthening ongoing crop improvement programmes.