关键词: 抽穗期, 超亲, 遗传分析, 感光性, 互补基因

Abstract: In remote crosses of indica and japonica rice varieties, maturation period transgression is a common phenomenon. In order to understand the genetic mechanism governing the phenomenon, the heading time of F₁ to F₃ and BC₁ generations under long day and short day conditions were inspected in crosses between Lunhui 422(a japonica-cline wide compatibility varieties) and two indica varieties Nanjing 11 and 188025 (with a genetic marker cluster spikelet controlled by Cl gene in chromosome 6). Under the long day, the heading time of F₁s was very late and their transgressive heterosis was over 49%. Two groups of plants(early and late) were obviously segregated in the F₂ and BC₁ populations or F₃ plant-lines, and the ratios of the early and late plants conformed to the complementary model of two pairs of genes. Under the short day and in the same crosses, the transgression of the F₁s was not remarkable and the heading time distributions in the F₂s appeared a single peak which were similar to the ones of the early group under the long day. This proved that the late heading of the F₁s was mainly caused by stronger photosensitivity of themselves and that the two genes above belong to photosensitive genes. The complementary test and linkage analysis showed that the one complementary gene in the two indica varieties was allelic, and that it was associated with the Cl gene and their recombination value was about 27.78±1.82%. According to the experiemental results, the complementation of photosensitivc genes may be the principal reason causing the maturation period transgression of the remote hybrids of rice.

Key words: gene complementation, genetic analysis, heading time, photosensitivity, transgression