Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: June 10, 2000
Publication Date: December 15, 2000
Citation: Timper, P., Holbrook, Jr., C.C., Xue, H.Q. 2000. Expression of nematode resistance in cultivated peanut. Journal of Nematology. 32:465-466. Technical Abstract: Several cultivated peanut genotypes have moderate resistance to Meloidogyne arenaria. Our objective was to determine the expression of resistance for six of these genotypes. We examined four potential expressions: 1) reduced penetration, 2) fewer second-stage juveniles (J2) establish functional feeding sites, 3) slower maturation, and 4) reduced fecundity. Peanut seedlings were inoculated with J2 of M. arenaria, and transplanted 3 days later to synchronize nematode development. The resistant genotyes were compared to the cultivar Florunner (F1r), a susceptible control. The number of juveniles within the roots of resistant genotypes was similar to F1r after 3 days, but lower than F1r in two of the genoytpes after 10 days. After 17 days, a greater percentage of J2 failed to develop in all of the resistant genotypes (72 to 79%) compared to F1r (50%). Of those that did begin to develop, the rate of maturation and fecundity was similar rin F1r and the resistant genotypes. The primary expression of resistance in the six peanut genotypes appears to be a reduction in the percentage of J2 that initiate a functional feeding site and begin to develop. Egression from roots after penetration may be a consequence of not establishing a feeding site.