Recurrent selection for resistance to Stemphylium vesicarium within the lucerne cultivars Trifecta and Sequel

Abstract

Two cycles of recurrent selection for resistance to Stemphylium leaf spot (caused by Stemphylium vesicarium) based on half-sib family performance were made within the lucerne cultivars Trifecta and Sequel. Within Trifecta, 1 generation of selection was sufficient to increase the level of resistance to that of UC 1249 (resistant check), while 2 generations were necessary to obtain equivalent levels of resistance in Sequel. The Stemphylium resistant lines maintained adequate levels of resistance to anthracnose (caused by Colletotrichum trifolii) and Phytophthora root rot (caused by Phytophthora megasperma f. sp. medicaginis) on the basis of glasshouse tests.