Abstract:

Root-knot nematode disease is one of important diseases on melon crops production in China, utilization of resistant materials is regarded as one successful way for the disease control. The purpose of this study was to provide scientific reference for more convincing resistance evaluation of towel gourd varieties even other crops varieties based on multiple indicators, and it will lay a foundation for breeding new root-knot nematode resistant varieties (including rootstocks) of luffa and melon vegetables. The resistance of six towel gourd materials were evaluated based on three indicators from field incidence investigation and laboratory tests from 2019—2020. The main results of the study were as follows: the pathogen identification of morphological characteristics showed the parasitic nematode was Meloidogyne incognita. The disease index (DI)of six towel gourd materials (No.1, No.2, No.5, No.6, No.32, No.33) were 65.3, 12.5, 55.3, 18.9, 32.0 and 34.3, respectively. The reproduction coefficient of M. incognita in the rhizosphere of six materials were correspondingly calculated as 1.28, 0.46, 1.12, 0.57, 0.73 and 0.78. While, the pathogenic nematode numbers in root tissues per 5 mm of six kinds of host were found to be 34, 4, 18, 7, 9 and 10 individuals.The average number of root nodules per 100 mm detected in the young root segments of six kinds of host were 12.2,2.1,14.8,0,0 and 0 individuals.The main results of field tests and artificial inoculation in greenhouse conducted in 2020, were consistent with those of field tests in 2019. The above results could be summarized that the materials No.2 and No.6 were high resistant (HR) to M. incognita, while No.32 and No.33 were resistant materials (R), the materials No.1 and No.5 were susceptible (S) to root-knot nematodes (M. incognita).

Key words: towel gourd, Meloidogyne incognita, reproduction coefficient, resistance evaluation