Ten early sweet corn inbred lines were studied for estimating components of genetic variance and heritability, using a factorial (m.n + n.m) mating design with reciprocal combinations. The genotype years interactions (G Y) influenced the expression of the most traits emphasize. submitting the importance of their evolution in different years. The additive effect values for yield components were highly significant in the genotypes studied here. Specific combining ability (SCA) variance was larger

more »

... than general combining ability (GCA) variance for kernel chemical composition and pericarp thickness. The predominance of SCA effects indicates that the pattern of carbohydrate accumulation in a hybrid depended upon the particular interaction of inbred lines involved in the crosses. Reciprocal (R) hybrids differences were detected for all kernel composition analysed. These differences should be attributed to an interaction of cytoplasm nuclear genome (R). The narrow-sense heritability estimate (h2) respectively the proportion of variance components to phenotypic variance for some ear traits are presented here. Genetic correlations among twenty traits submitted an unfavourable genetic correlation between sucrose-row number, silking data-total sugar and total sugar-ear weight that suggest the difficulties in obtaining early sweet corn hybrids high yielding with a good quality.