Resistance Evaluation of Capsicum spp. Germplasm to Meloidogyne incognita

[Objective] This study aimed to screen out hot pepper germplasms highly resistant to Meloidogyne incognita, thereby providing resistant resources for hot pep- per breeding. [Method] Comprehensive analysis combining cluster analysis and sub- ordinate function was conducted through determining related resistance indexes of 67 hot pepper germplasms 50 days after inoculated with M. incognita. [Result] The effects of M. incognita on related resistance indexes were significantly different am- ong the hot pepper germplasms. Egg index and gall index had abundant genetic variation with variation coefficients of 143.16% and 118.95%, respectively. Based on the gall indexes, cluster analysis of hot pepper germplasms was performed. The 67 hot pepper germplasms were divided into 4 groups （resistant, moderately resistant, susceptible and high susceptible）. The resistance intensity of the hot pepper germplasms were ranked according to the sum of subordinate function values of various resistance indexes. The total function values of Rela 2 and L506M were the largest （2.00）, indicating that these two germplasms were immune to M. incognita. The total function values of L287-2, L522-1M, L504M, L515-2, 13SM100-1, L512M, L292-1, L319, L316, L317, 13SM87-1 and Rela 5 were larger than 1.95, indicating that these germplasms were highly resistant to M. incognita. [Conclusion] This study could provide certain resistant resources for resistance breeding of hot pepper to M. incognita.

Identification and Evaluation of Resistance to Meloidogyne incognita in Bitter Gourd Germplasms

[ Objective] This study aimed to identify and evaluate the resistance of bitter gourd germplasms to Meloidogyne incognita. [ Method] A total of 71 bit-ter gourd germplasms were artificially inoculated with M. incognita at seedling stage to investigate the effects of M. incognita on resistance indexes of bitter gourd seedlings. Cluster analysis and subordinate function analysis were performed to identify and evaluate the resistance of experimental materials. [ Result] The infec-tion of M. incognita increased the variation coefficients of resistance indexes. The resistance to M. incognita varied significantly among different bitter gourd germ- plasms. Based on gall index, 71 bitter gourd germplasms were divided into five types by cluster analysis, including resistant materials, moderately resistant materi-als ,moderately susceptible materials, susceptible materials and highly susceptible materials. The subordinate function analysis showed that total subordinate func-tion values of Y107, Y109, Y108, Y51, Y105, Y81, Y89, Y140 and Y94 exceeded 1.95 , indicating high resistance to M. incognita. [ Conclusion] This study could provide resistant materials for breeding root-knot nematode resistant varieties of bitter gourd.