【摘要】 本研究是结合育种实践,连续进行了五年的试验。主要是探讨水稻不同生态型亲本组合以及不同生态型的双亲生育期差异对 F₁和 F₂抽穗期的影响。试验结果,F₁抽穗期表现为:双亲生态型差异大的,F₁超早超晚均突出,双亲生态型相近的,F₁倾早倾晚机率相差不大。而 F₁的倾早倾晚与双亲生育期差异无趋向性的关系。F₁抽穗期的显性效应均不明显。F₂抽穗期的分离变幅表现为:双亲抽穗期相差越小,超早百分率越高;反之,相差越大则越低。另方面,双亲生态型差异越大,倾晚越突出;反之,生态型相近则倾早倾晚均不明显。抽穗期的遗传力和预期的遗传进度均达很高水准;双亲和 F₂的回归、相关均极显著;表型变异系数和基因变异系数相近,均很小。总括试验结果,水稻抽穗期的变异主要受遗传的制约。更多还原

【Abstract】 Observations on genetic variability of dates of heading of F₁and F₂ generations of 384 single crosses among various ecologicaltypes in rice were made during the period of 1975-1978.The resultswere summarized as follows1.The first generation hybrids between different ecological types showeda great variability in their dates of heading.The F₁ crosses betweendistant ecological types showed outstanding transgression in the date of hea-ding,whereas those between less-distant types expresed no transgression;in the latter case the numders of the early and late crosces were nearlythe same.Dominant effect on the date of heading was not apparent.2.The diffenence between dates of heading of the parents functioned re-gularly as a controlling factor for the transgressive as well as the non-trands-gressive earliness in the F₂ generation.The smaller the difference betweendates of heading of the parents,the higher was the ratio of transgressiveearliness,whereas a larger difference resulted in lower ratio.This ten-dency held true for all the different types of crosses.This fact is very im-portant in the choice of parents and making crosses for earliness.3.The inheritance of date of heading in rice appeared mainly to becontrolled by polygenes;most of the F₂ populations gave more or less uni-modal distribution.And some modifications were found in several crosses.4.The heritability of the date of heading in rice was very high.Boththe phenotypic and the genotypic coefficients of variability were small,and the difference between these two values was also small,indicating thatthe date of heading was mainly controlled by genotypes.更多还原