Inheritance of Shortened Fruit Maturation in the Cherry Tomato Cornell 871213-1 and Its Relation to Fruit Size and Other Components of Earliness

Abstract

The heritability of shortened fruit maturation (SFM) period in Cornell 871213-1, an inbred cherry tomato [Lycopersicon esculentum var. cerasiforme (Dunal.) A. Gray] line, was estimated from a greenhouse experiment. Cornell 871213-1 was crossed with the cherry tomato line NC 21C-1. Mean fruit maturation period (FMP) (days from anthesis to the breaker stage of fruit color) was 40.8 days for NC 21C-1 and 32.0 days for Cornell 871213-1. Parental, F 1 , F 2 , and backcross generations all differed in mean FMP and yielded, estimates of broad- and narrow-sense SFM heritabilities of 72% and 40%, respectively, on a single-plant basis. A test for midparent heterosis showed significance. Genetic control of SFM was quantitative in nature and highly dominant. A field study of an F 2 population developed from the cross Cornell 871213-1 × NC 84173, the latter a large-fruited tomato line (Lycopersicon esculentum Mill.), gave a mean FMP of 48.4 and 31.2 days for NC 84173 and Cornell 871213-1, respectively. The F 1 and F 2 generations had FMP of 33.1 and 34.7 days, respectively. The parents, F 1 , and F 2 generations all differed in FMP. Parental, F 1 , and F 2 generations yielded an estimate of broad-sense SFM heritability of 64% on a single-plant basis. F 3 progenies from selected F 2 s were grown in a greenhouse, and F 3 -F 2 regression analysis gave a narrow-sense SFM heritability of 39%. Parental means differed from each other and from the F 1 and F 2 means for period from sowing to anthesis, fruit weight, and locule number. F 1 and F 2 means did not differ for any trait and were far below the midparent values, approaching Cornell 871213-1 for each trait except for the number of days from sowing to anthesis. Significant correlations existed in the F 2 generation between FMP and fruit weight (0.61) and between fruit weight and locule number (0.69). Significant correlations existed between selected F 2 s and their F 3 progeny for FMP (0.53), fruit weight (0.78), and days from sowing to anthesis (0.78). In the F 3 generation, a significant correlation occurred between FMP and fruit weight (0.48). F 3 -F 2 regression and realized heritabilities were used as two estimates of narrow-sense heritability (29% and 31%, respectively) for days from sowing to anthesis.