Inheritance of Some Characters in Cucumber, Cucumis sativus L.

II. Some Quantitative Characters

Abstract

The mode of inheritance of eleven quantitative characters was studied. The long cotyledonary leaf was completely dominant over the short one. A minimum of 2-3 pairs of genes seemed to control this character. The heritability of this character was 60.84%. With regard to width of the cotyledonary leaf, the F( exceeded the large parent indicating a case of heterosis. The minimum number of genes was one pair and the heritability was 56.46%. A case of overdominance was noted in cotyledonary leaf shape where the F, mean was less than the small parent. The minimum number of genes was one pair and the heritability 61.10%. The surface area of the cotyledonary leaf also showed overdominance of the parent with large area. One or two pairs of genes seemed to be involved and heritability was 61.36%.
Weight of the mature fruit showed partial dominance of the light fruit. The minimum number of genes was 3-4 pairs and heritability was 44.18%. The short fruit was dominant over the long one. Five pairs of genes seemed to be controlling this character and the heritability was 54.51%. The smaller diameter of the fruit was partially dominant over the large one with about 4 pairs of genes as might be controlling that character. A low value of heritability was obtained (15.34%) indicating that environmental factors had more effect on this character than genetic factors. The low shape index of the fruit (long-slender) was completely dominant over the high index. One pair of genes was estimated as the minimum number of genes controlling this character. Heritability was 59.22%. Diameter of seed cavity in the mature fruit showed partial dominance of the narrow seed cavity. About 3-4 pairs of genes were controlling this character. Heritability was 28.65%. No high correlation could be detected between cotyledonary leaf characters and fruit characters. On the other hand high positive correlation coefficients were obtained between the length and the diameter of mature fruit, and between the diameter of mature fruit and the diameter of seed cavity in the mature fruit.