Investigations on the inheritance and responses to selection of riceyness in early summer cauliflower

Abstract

F₁'s grown from crosses between cauliflower plants with perfect and very ricey curds showed a continuous distribution in the degree of riceyness (classified into four grades) with slight dominance of the most ricey grades. The effect of environment upon the expression of riceyness was shown, by X² tests on F₁'s, F₂'s and selfed parents grown in more than one year, to be limited.

Selections made consistently over three generations for grade 1 curds resulted in marked increases in the proportion of curds in that grade, but selection for grade 2 and 3 curds over two generations was less successful. When disruptive selection was practised, i.e., the selection of plants showing a different grade from that for which the parent was selected, the progenies of these plants generally showed an increase in the proportion of the newly selected grade.

From these results it was concluded that the inheritance of riceyness appeared to be under polygenic control and that plants were still heterozygous for polygenes at the F₃ generation.