Resistance to Sphaerotheca fusca in local germplasm of Cucumis melo

• Published in: Journal of plant pathology 2003-12, Vol.85 (4), p.287-287
• Main Authors: Longo, O, Ambrico, A, Schiamone, D, Ciccarese, F
• Format: Article
• Language: English
• Subjects: Cucumis melo; Sphaerotheca fusca
• ISSN: 1125-4653

The Mediterranean basin is considered an area of genetic diversification of Cucumis melo L. and in Southern Italy, Apulia in particular, an ample and diversified local germplasm of Cucumis melo subsp. melo conv. adzhur is available. This cucurbits is a relict of melon cultivars selected for use as immature fruits. In screenings for resistance towards Sphaerotheca fusca on local germplasm of C. melo subsp. melo conv. adzhur, a plant belonging to the BA7-2 ecotype resulted healthy. In the following screenings carried out on BA7-2/S progeny obtained by self-fertilization of healthy plants, three different reactions towards S. fusca were recorded: plants with severe symptoms, healthy plants and plants showing a restricted development of the disease. This last reaction consisted in the appearance on the leaves of small chlorotic areas covered with thin mycelium and with rare sporulation. On the same areas a netlike necrosis was visible. Single plants belonging to the three typologies of disease reaction were self-fertilised and the progenies were tested. All plants of progenies obtained by self-fertilization of healthy plants resulted healthy; the plants derived by self-fertilization of susceptible plants showed disease symptoms. The progenies derived by self-fertilization of plants showing limited symptoms segregated 39% of healthy plants, 28% of susceptible plants and 33% of plants with limited symptoms. This segregation ratio suggests that the resistance found in the BA7-2 ecotype of C. melo subsp. melo conv. adzhur is oligogenic. Further specific investigations on the inheritance of resistance in the BA7-2 ecotype are in progress.