STUDIES ON THE INHERITANCE OF THE HEADING TIME IN HYBRID RICE Ⅰ.The Genetic Performance of F₁ Heading Time

Two early-maturing indica male sterile lines(A), V20A with the cytoplasm from the wild abortive rice plant, and Zhen Ding 28A with the cytoplasm from the Indonesian paddy rice NO. 6, and their maintainer lines(B), six indica restorer lines(R)and an American early-maturing indice variety(V), Blue Belle, were used as parents to produce 72 F1 crosses including A/B, A/R(V), B/R(V), R(V)/B. The results of genetic analysis of heading time of F1 hybrids could be summarized as follows:1)The major genes for heading are apparently different in these two male sterile lines(maintainer lines).2)There could be different in the major genes in the restorer lines(variety).3)Both of the two kinds of the cytoplasms of male sterility have no apparent effect on the heading time.