Studies on a diallel cross and double-cross hybrids among various Brassica oleracea types

Summary Three unrelated pairs of inbred lines from marrow-stem kale (A), thousand headed kale (B), and Scotch curled kale (C), together with 3 lines from Chou Fourrager Jaune (D), Brussels sprouts (E), and January King cabbage (F) were used to produce a diallel cross.Study of the F₁ generation revealed that general combining ability was highly significant for all yield components studied and specific combining ability was also significant for all but at a much lower level. Greater heterosis for leaf yield, but not for stem yield, was indicated in the inter-type hybrids as compared with intra-type hybrids.Double-crosses made among F₁ from the paired inbred lines did not reveal consistent effects of order of combining the inbred lines on yield characters, but the large differences in plant-to-plant uniformity showed that only the (X₁×X₂)×(Y₁×Y₂) combination is likely to be of practical significance.