低磷胁迫下不同水稻基因型苗期根系性状的遗传研究

目的]为开展水稻耐低磷种质资源的遗传育种研究提供理论依据和遗传基础。方法]对1个耐低磷水稻基因型和1个低磷敏感基因型,以及它们的正反交F1、RF1及F2后代的根系性状的遗传基础进行研究。结果]结果表明:F1代的耐低磷性向高值亲本99112偏斜,表现出一定的杂种优势。正反交F1代的表型值几乎没有差异,可以推断为细胞核遗传。F2表现为连续变异性状,即数量性状。结论]主根长符合E-1模型(2对加性-显性-上位性主基因+加性-显性多基因混合模型),主基因遗传力为62.47%,多基因的遗传力为20.49%;而根干重与根冠比这二个性状符合D-0(1对加性-显性主基因+加性-显性-上位性多基因遗传模型),其主基因遗传力分别为38.73%和59.80%,而多基因的遗传力分别为27.56%和35.60%。

Heredity Research on the Root Characters of Rice Genotype in Seedling Stage under Low Phosphorous Stress

Objective] The study aimed to provide theoretical basis and heredity base for developing heredity and breeding research of germplasm resources of rice with low phosphorous(P) tolerance.Method] The heredity base of root characters of a rice genotype with low P tolerance and a rice genotype sensitive to low P and their reciprocal crosses F1,RF1 and F2 was studied.Result] The low P tolerance of F1 generation declined to the parent 99112 with high value,showing some heterosis.The phenotypic values of reciprocal crosses F1 nearly had no difference and could be concluded as nucleolus heredity.F2 showed to be continuously variant character,i.e.quantitative character.Conclusion] The length of main root accorded with E-1 model(mixed heredity model of 2 pairs of additive-dominant-epistatic major genes additive-dominant multigene),with the hereditary capacity of major gene being 62.47% and that of multigene being 20.49%.But the 2 characters of dry weight of root and ratio of root to coronal accorded with D-0(heredity model of a pair of additive-dominant major genes additive-dominant-epistatic multigene),with the hereditary capacity of major genes being 38.73% and 59.80% resp.,and that of multigenes being 27.56% and 35.60% resp.