Journal of Taiwan Agricultural Research

Author:Yu-Hua Wang*, Jin-Hsing Huang, Tzu-Kai Lin, San-Tai Wang and Chi-Hsiung Hsiao

Abstract:

    Leaf disc inoculation method was used to evaluate the resistance of 19 commercial cultivars of Cucumis melo L. to Sphaerotheca fuliginea race 1, the causal agent of powdery mildew in Taiwan. The results showed that 3 of the entries, i.e. Autumn waltz No.2, Chengfang, and Mihua, were resistant, while the rest 16 varieties were susceptible. This indicated that most of the melon cultivars in Taiwan are susceptible to S. fuliginea race 1. The disease reactions of a total of 36 melon inbred lines (S₈～S₁₂), developed in our institute, to the same pathogen were also tested by using the same screen method. Among them, 21 inbred lines showed resistant and the other 15 lines were susceptible. In order to understand the inheritance of resistance to S. fuliginea race 1 in the resistant inbred line 02080 (S₁₂) cross hybridization between inbred line 02080 and a susceptible inbred line 02077 (S₉) was conducted. The parents (P₁ and P₂) and their progenies, including F₁, F₂, BC_R, and BC_S, were inoculated and the disease response in each individual plant was recorded and analyzed. The segregation ratios of resistance vs. susceptibility obtained from this experiment indicated that the resistance trait seems being under the control of a single dominant gene.

Key words:Melon, Powdery mildew, Resistance screening, Breeding for resistance, Genetic analysis

Download: PDF Links