Assessment of bitter gourd (Momordica charantiaL.) genotypes for resistance against downy mildew

Twenty two genotypes of Momordica charantiaand Momordica charantiavar. muricatawere screened against downy mildew caused by Pseudoperonospora cubensisunder artificial condition and natural field condition for resistance to Pseudoperonospora cubensis. The mean PDI on 15th days after inoculation (DAI) under artificial screening ranged from 11.40 to 89.45%. No genotype was found to be highly resistant to downy mildew. The genotypes MC 48, MC 49, MC 50 and MC 53, which showed mild symptoms, with PDI ranging from 11.30 to 23.45%, were moderately resistant to downy mildew. The genotypes, Preethi (88.95%), Priya (89.40%), Priyanka (89.45%), MC 51 (83.40%), MC 52 (80.30%), MC 54 (88.70%), MC 55 (60.25), MC 57 (72.75%), MC 58 (86.30%), MC 59 (84.95%), MC 60 (88.45%), MC 61 (88.65%), MC 62 (82.20%), MC 63 (84.45%), MC 64 (76.85%), and MC 65 (86.45%) were found to be susceptible to the disease. Six genotypes(3 most resistant and 3 highly susceptible) selected from the artificial screening viz. Priya, Preethi, Priyanka, MC 48, MC 49 and MC 50 were evaluated under natural conditions during monsoon season. None of the genotypes exhibited complete resistance against the pathogen. The genotypes MC 50 and MC 48 showed the lowest PDI of 11.04% and 11.98% respectively and were categorised as moderately resistant, while the genotype Priyanka with PDI of 85.22% was susceptible to the disease. The yield attributing parameters such as earliness to first female flower production (38.44 days), first harvest (53.80 days) and the highest yield (4.94 kg plant− 1) was recorded in Priyanka. This identified bitter gourd genotypes can be used for further breeding programmes for the development of new hybrids/ varieties.