Enhancement of muskmelon resistance to disease via breeding and transformation

An Indo-Israel joint research project on "Enhancement of muskmelon resistance to disease via breeding and transformation", jointly sponsored by India and Israel, is in progress. One of the objectives of research for Indian side is the examination of Indian land races of Cucumis melo for disease resistant genes (downy mildew and virus) which are not allelic to the known genes. In Israel the protocol is developed by Dr. Y. Cohen for cloning the P45 gene from C. melo PI 124111F which carries Pc-1 and Pc-2 genes. Other line PI 124112 which carries Pc-1 and Pc-4 genes. In India, the author has collected and evaluated 150 non-dessert forms of muskmelon including Phoot or snapmelon (C. melo var. momordica), Kakri, Kachri, Pickling melon, Cooking melon, Naka Dosa Kaya, Vellarikkaya, C. callosus, etc. from all the parts of India and were evaluated for downy mildew (Pseudoperonospora cubensis) resistance in five independent screenings under natural epiphytotic conditions. Five snapmelon (Cucumis melo var. momordica) genotypes viz. 55-1, 55-2, 77, 113 and 114 were found to be resistant to downy mildew and notably the former two were most important in this respect. Further, these five accessions along with PI 124111F and PI 124112 and one susceptible check Monoecious-3 were subjected for electrophoresis studies. The results clearly indicated that the resistant lines identified in the present study are genetically distinct from PI 124111F and PI 124112. Earlier at Indian Agricultural Research Institute, New Delhi More et al. (1993) developed five lines viz., VRM 5-10 (DVRM-1), VRM 29-1, VRM 31-1 (DVRM-2), VRM 42-4 and VRM 43-6 which are highly resistant to cucumber green mottle mosaic virus (CGMMV). Phoot was identified as CGMMV resistant source and exploited to develop these lines. Further these lines were screened for multiple disease resistance (CGMMV and downy mildew) at National level in multilocational trials of All India Co-ordinated Vegetable Improvement Project over several years. In the year 2001, VRM 5-10 (DVRM-1) and VRM-31-1 (DVRM-2) are identified as CGMMV plus downy mildew resistant breeding lines at National level.