Investigation of reactions of eggplants genotipes against avirulent and virulent populations of Meloidogyne incognita

Eggplant is one of the most important vegetables cultivated in the world; however, root-knot nematodes cause serious yield losses in eggplant production. The use of eggplant rootstocks resistant to root-knot nematodes is one of the most effective management methods. The resistant rootstock, Solanum torvum (Sw.) is only used to control root-knot nematodes in Turkey. Therefore, investigating new gene sources is necessary to manage root-knot nematodes. Tomatoes carriying Mi-1 gene are commonly used to control root knot nematodes. However, resistance genes such as Mi-1 can be overcome by virulent nematode populations. Thus, understanding the response of other vegetable species, such as eggplant, to virulent roo-knot nematodes populations is required for integrated management practice. In the present study, the response of eggplants genotypes to avirulent (S6) and Mi-1 virulent (V14) isolates of Meloidogyne incognita was investigated under controlled conditions. A total of 61 eggplant genotypes were used in the experiment. Five replications for each genotype were taken for the screening test in a randomized parcel design. Eggplant seedlings with two or four true leaves were inoculated with 1000 second stage juveniles of M. incognita. The plants were kept in a growth chamber (16-h photoperiod 25±0.5ºC, 65% relative humidity) for 8 weeks after nematode inoculation. They were then uprooted and the roots were carefully washed in running tap water. The number of egg masses and galls on the roots and second stage juveniles 100 g soil per pot were counted. Y-3 (S. aethiopicum), Y-8 (S. integrifolium) and Y-28 (S. torvum) were resistant to avirulent S6 isolate of M. incognita, and Y-3 (S. aethiopicum), Y-28 (S. torvum), Y-12 (P-5) and Y-15 (S. incanum) were resistant to virulent V14 isolate of M. incognita. The remaining materials were susceptible to avirulent (S6) and virulent of (V14) M. incognita. The reproduction factor for nematodes on plants with resistance according to gall index scale was <1, while the reproduction factor for nematodes on susceptible plants was >1, as expected. The resistant genotypes could be used in eggplant breeding and management of root-knot nematodes.