Inheritance and Allelism of Genes for Resistance to Races 1 and 2 of<i>Sphaerotheca fuliginea</i>in Muskmelon

Abstract

Crosses between Cucumis melo var. reticulatus lines PI 124111F, PI 124112, and PMR 6, which are resistant to powdery mildew, and Ananas-Yokneam, the universal susceptible line, were made. Crosses between each pair of the resistant lines were also made. Parents and F 1 , F 2 , BC S , BC R , and TC progeny plants were inoculated with either race 1 or 2 of the powdery mildew pathogen, Sphaerotheca fuliginea, in growth chambers. Segregation ratios between resistant, moderately resistant, and susceptible offspring were determined (.)