|Williams, William - Paul|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/2000
Publication Date: N/A
Technical Abstract: The objective of this study was to evaluate the inheritance of resistance to root-knot nematode (Meloidogyne incognita)(RKN) in sweet corn x RKN- resistant field corn crosses. Crosses were made between four resistant field corn germplasms, Mp709, Mp710, Mp711, and Mp712, and five shruken-2 (sh-2) sweet corn inbred lines. Parents, F2's and F3's were evaluated in the greenhouse by inoculating each plant with 4000 RKN eggs and counting the number of egg masses on each system after 60 d. Analysis of the parents indicated that one sweet corn inbred, R16, had egg mass counts similar to those of the RKN-resistant parents in both years. Genotypes from cross Mp712 x R16 also exhibited levels of resistance similar to the resistant parents. Chi-square goodness-of-fit tests suggested that RKN-resistance was controlled by a single dominant gene. Broad-sense heritability estimates were 0.88 for the F2 generation and 0.89 for the F3 generation. Quantitative genetic analysis revealed that dominance variance accounted for 50% of the phenotypic variance, additive variance accounted for 16%, and residual variance accounted for 34%.