بررسی چرخه زندگی و میزان تکثیر نماتد javanica Meloidogyne روی چهار رقم متداول بادمجان در شرایط گلخانه

Root-knot nematodes (Meloidogyne) are among the most severe pathogens affecting eggplant. Utilizing resistant cultivars is an alternative to chemical nematicides, which pose significant environmental risks. In the present study, the life cycle of M. javanica was evaluated on four eggplant cultivars under controlled conditions. Seeds of four eggplant cultivars (Black Beauty, Fazli, Noorabad, and Hormozgan) sown in 250-gram plastic pots containing a growth medium (equal amount of farm soil, sand, and decomposed manure). Pots were maintained in a growth chamber at 27 ± 1°C, under 16:8 h (light: dark) photoperiod. Four-leaf stage seedlings inoculated with 100 ± 20 second-stage juveniles (J2) of M. javanica. The plants harvested at 3, 6, 9, 12, 15, 18, 21, 24, and 35 days post-inoculation (dpi), and nematode life stages, number of nematodes in roots, number of nematode egg masses, and number of eggs per egg masses were evaluated. The results showed that in Noorabad and Hormozgan cultivars, the first adult female nematodes were appeared at 15 dpi, while in Fazli and Black Beauty cultivars, the first adult female nematodes were appeared at 18 dpi. On days 18, 21, 24, and 35 dpi, the ratio of mature females to the total nematode population in the roots of Fazli was 5, 16.9, 25, and 47.4%; in Black Beauty was 18, 26.9, 41.8, and 64.6%; in Noorabad was 8, 35.6, 72, and 85.1%, and in Hormozgan was 12.2, 32.9, 86.5, and 87.7%, respectively. The ratio of egg masses number to mature females in Fazli was 0, 0, 53.8, and 94.4%; in Black Beauty was 9.1, 100, 100, and 96.7%; in Noorabad was 0, 97.3, 100, and 100%, and in Hormozgan was 0, 47.8, 100, and 100% on days 18, 21, 24, and 35 dpi, respectively. The reproduction factor (calculated by dividing the final nematode population by the initial nematode population) in Fazli calculated by 0.71, 8.24, and 41; in Black Beauty was 4.6, 8.5, and 37.7; in Noorabad was 6.8, 65.9, and 122, and in Hormozgan 20.7, 38, and 73.8 on days 18, 24, and 35 dpi, respectively. Consequently, although Black Beauty and Fazli cultivars showed differences with the other two cultivars by causing a delay in completing the life cycle and reducing the number of nematode eggs, but all four eggplant cultivars were susceptible to M. javanica.