Reproduction of Root-Knot Nematode, Meloidogyne incognita, on Solanum melongena Determines their Host Status

In Pakistan, the low yield of eggplant is ascribed to legions of biotic constraints. Among biotic restraints, root-knot nematodes, Meloidogyne spp. are economically very important and cause losses to the tune of $ 125 billion per year throughout the world. The present studies were aimed to evaluate 21 eggplant genotypes against the most destructive nematode, Meloidogyne incognita, under greenhouse conditions. Of all the genotypes/varieties of eggplant, Janak and Pala were found resistant and moderately resistant to M. incognita respectively. Fifteen varieties/lines viz. EP-972, Kokila F1, EP-950, EP-906, Jhansi F1, Adv301, KHBR-201, KHBR-202, KHBR-203, KHBR-204, EP-900, 2016, KHBR-205, EP-966 and Sultan were found susceptible while four genotypes namely Nirala, Dilnasheen, Wer and Bemisal showed highly susceptible reaction against M. incognita. All the genotypes showed significant differences in number of galls, eggmasses, females, root and soil populations, reproductive factors and eggmass/gall and eggmass/ female ratios. Minimum galls, eggmasses, and females were observed on resistant and moderately resistant genotypes. On the other hand, maximum values in these parameters were recorded on susceptible and highly susceptible genotypes/lines. Similarly, minimum number of juveniles were recovered from roots and soils of resistant genotype (Janak) followed by moderately resistant genotype (Pala) while maximum juveniles were recovered from roots and soils of susceptible and highly susceptible genotypes. Likewise, variations were also observed in reproduction of the nematode on 21 genotypes. Minimum reproductive factor of M. incognita was observed on Janak followed by Pala and maximum was recorded on Dilnasheen followed by Nirala. The reproductive factors on other genotypes were variable. A similar trend was observed in case of eggmass/gall and eggmass/female ratios in all the genotypes.