Search Results
Abstract
Early blight resistance was estimated in field plots for parents and F1, F2, and backcross progenies of crosses with NC EBR-1, a line derived from Lycopersicon hirsutum P.I. 126445. Areas under the disease progress curve (AUDPC) showed that resistance from NC EBR-1 was heritable and quantitative in nature. generation means in two families were intermediate to those of NC EBR-1 and susceptible parents. The distribution of AUDPC means for the different generations in both families indicated the presence of epistasis or gene linkage. Lack of fitness tests for curve-linearity confirmed this in one family. A, B, and C scaling tests showed similar results. A joint three-factor model and subsequently a six-factor model displayed the presence of epistasis in both families. Ignoring epistatic effects, narrow-sense heritability (h2) was 0.49 in one family and 0.40 in the other. By regressing F3 progeny AUDPC means on selected F2 plant values, h2 was 0.25 and 0.17, respectively.
Abstract
Eight stamenless tomato mutants (Lycopersicon esculentum Mill.) were intercrossed in a half-diallel design to determine allelic relationships. Two allelic series were represented among the mutants. One series included sl, sl 2 , sl 5, cs, and fl. The 2nd series included bn, sl?, and pms. No allelic interactions occurred between members of the 2 series. Fruit and seed set resulting from cross-pollinations varied greatly among the mutants. The stamenless types, with the exception of sl 2, do not appear to be promising for use in producing hybrid tomato seed because of poor fruit and seed set.