Transfer of resistance to floury leaf spot and bacterial blight in french bean from alien germplasm

Resistance to floury leaf spot caused by Mycovellosiella phaseoli and bacterial (fuscous) blight caused by Xanthomonas axonopodis pv. phaseoli of french bean (Phaseolus vulgaris) was found in alien Phaseolus species P. coccineus and P. acutifolius. An attempt was made to transfer resistance from these species to french bean by means of interspecific hybridization. Two hybrids of P. vulgaris (contender) x P. acutifolius (G 40015 and G 40020) and five of P. vulgaris x P. coccineus (Pc1 and Pc2) were free of floury leaf spot but exhibited varying number of fuscous blight lesions. However, lesion size in these hybrids was highly restricted except in hybrids with G 40015 and G 40020. Five inter-specific hybrids of P. vulgaris (Him1) x P. coccineus were resistant to both bacterial blight and floury leaf spot.