Plant Disease Research

Different muskmelon lines can be exploited for their disease resistance genes in plant breeding programmes. A large number of lines of muskmelon are available with great degree of variation in severity to downy mildew. A collection of 34 lines of muskmelon was screened against downy mildew during 2007–08 season. All the lines were artificially inoculated with sporangial suspension (1x 10⁴ sporangia/ml) of Psuedoperonospora cubensis. The inoculum was multiplied on muskmelon leaves following detached leaf technique. Disease severity was recorded after 15 days of inoculation. Data revealed that 6 lines viz. IC 274014 (snapmelon), Pusa Sharbati, MCPS-2, MCPS-7, MCPS-17, Mehna Chibber showed high resistance to downy mildew with the disease severity of 2.0, 5.0, 1.6, 3.8, 5.0 and 2.8% respectively. Lines viz. IIVM-3, MM-28, Pusa Madhuras, MCPS-1, MCPS-3, MCPS-5, MCPS-9, MCPS-10, MCPS-11, MCPS-12, MCPS-19, MCPS-20, MCPS-21 and Durgapur Selection-1 were found to be moderately resistant to downy mildew and showed disease severity of 15.0, 15.0, 20.0, 14.8, 15.0, 20.0, 12.0, 10.0, 8.0, 8.0, 12.0, 8.0, 15.0, and 18.0%, respectively. Remaining 14 lines were found susceptible to downy mildew, which depicted disease severity in the range of 22–55%. Lines with high level of resistance can be used in breeding programme to develop downy mildew resistant varieties of muskmelon.