影响籼粳稻DNA限制性片段长度多态性检测的因素分析

对窄叶青(籼稻)和京系17(梗稻)的RFLP进行了系统分析。结果表明,某种酶多态性检测能力与同时检测到此多态性的其余酶的数目之间存在极显著的正相关(r=0.962**)。由此推论,籼粳稻大部分RFLP可能来自大范围DNA的结构变化而不是碱基取代。cDNA克隆虽然具有高度的保守性,但却具有比基因组克隆更高的多态性检测能力。在实验使用的探针范围内,探针长度和检测到的多态性无相关性。由探针检测到的多态性位点均匀地散布在水稻的12对染色体上,这可能是这两个品种所属的亚种之间的遗传距离较大的原因。

Analysis of Factors Involved in Detection of Restriction Fragment Length Polymorphisms Between Indica and Japonica Rice (Oryza saliva L.)

Restriction Fragment Length Polymorphisms (RFLPs) between two rice varieties, Zhaiyeqing (Indica) and Jingxi17 (Japonica), were analyzed. The results indicated that probability of detecting polymorphisms with a given enzyme and a given probe is a function of the number of other enzymes detecting polymorphism with that same probe consequently, we deduced that RFLPs between Indica and Japonica rice are generated largely by large scale changes in chromosomal DNA rather than base substitutions. cDNA clones can detect more polymorphisms than genomic clones, though its coding region is more conserved than other sequences in genome. It seems likely that the polymorphisms detected with cDNA clones occur either in the introns of genes or in the outside of coding regions. No significant correlation was found between probe size and polymorphism. Polymorphisms revealed by all tested probes were evenly distributed on 12 pairs of rice chromosomes, this might b?attributed to the great genetic distance between the two subspecies.