The Inheritance of Cercospora Leaf Spot Resistance in the Southernpea (Vigna unguiculata (L.) Walp.)1

Abstract

Two southernpea breeding lines, CR 17-1-34 and Ala. 963.8, highly resistant to a leaf spot incited by Cercospora cruenta Sacc. were crossed with susceptible cultivars. The F 1 and F 2 progenies of these crosses, the F 1 of the backcrosses, and the parental lines were grown in field experiments in which natural Cercospora leaf spot epiphytotics were allowed to develop. The resistances in the two breeding lines were found to be conditioned by different genetic factors. Resistance in CR 17-1-34 was controlled by a single dominant gene and that in Ala. 963.8 by a single recessive gene. We propose that the dominant and recessive genes to be designated Cls 1 and cls 2 , respectively.