植物育種法に関する理論的研究 : II.自殖性作物の交配育種における組合せ検定法の理論

抄録

It has often been suggested by several gerleticists that the potentiality in hybrid populations to segregate superior yielders in later generation could be detected by examination of the yields of the. F₂ or F₃ populations. But it has been demonstrated by others that this does not always hold true. In, this paper a theoretical approach is made to that problem. Suppose at first the simplest case where the expression of a character which we are going to select is neither influenced by any environmental condition nor by any non-additive gene effect. In such cases, the mean value of the character of a hybrid population would reasonably represent an estimate of the additively genetic mean of the population and the mean. square would provide an estimate of the additively genetic variance. If individuals of such a population are distributed normally regarding the measurements x, with mean at x and variance (r2 we can transform x to a variate u, with unit variance and mean at zero. That is, u=(x-x)'1, ' (See Figure I in the text). If we select a definite proportion of superior individuals which are included in the shaded area A in Fig. l, the selec. ti;on, differential expressed in the standard deviati.on.Ican be computed as