DIALLEL ANALYSIS OF LOW TEMPERATURE SPROUTING ABILITY IN TOMATO POPULATIONS EVALUATED IN FIELD AND LABORATORY ENVIRONMENTS

Abstract

Diallels with parents, F1, and F2families of tomato (Lycopersicon esculentum Mill.) were evaluated for low temperature sprouting ability in laboratory and field environments. The diallel analysis of variation among parental and F1or F2families indicated that differences attributable to additive, dominance, maternal, and residual effects were fairly consistent over laboratory and field experiments. Additive effects were the most important source of variation in both laboratory and field experiments, accounting for 46 to 85% of the total variation among families. Dominance effects specific to parents or hybrid families were significant in all laboratory experiments but accounted for less than 12% of the total variation among families. Maternal effects were the second largest source of variation among F1families (28%) and among F2families in two field experiments (8 and 18%) but accounted for less than 3% of the family variation in the F2laboratory experiments. Analysis of the Wr-Vr graph for the F2generation revealed departures from some of the assumptions required for the diallel analysis. These departures from assumptions were not detected in the analysis of the F1generation. Good agreement was obtained between field and laboratory environments. Preliminary screening for cold sprouting ability in tomatoes could be conducted in the laboratory.