诱发籼稻早熟同型系的研究 Ⅰ.早熟同型系的发生及其规律

在同一籼稻类型品种中,早熟同型系发生率4年间基本类似(分别为1.41%、1.37%、1.42%、1.64%),但在不同生态类型品种中早熟同型系发生率则不相同:早熟种为0.73%,中熟种为1.51%,迟熟种为1.97%.系谱亲缘相同的品种,其早熟同型系发生率各自相似;系谱不同的品种则相反.早熟同型系发生的基本规律与特点:1.早熟同型系发生的基础是抑制的表现型;2.早熟同型系的发生与原品种的生育期密切相关;3.出现早、晚熟双向熟期变异的同时,发生株型、叶型等性状的平行变异;4.早熟同型系的发生有不平衡性.早熟定向诱变育种,根据同型系系列的基本原理,只要准确地了解和掌握种、属类型、品种生态特性和品种系谱亲缘3个方面,就能预估诱变后代产生早熟同型系,进行早熟定向诱变,培育新品种.

HOMOLOGOUS SERLES OF INDUCED EARLY MUTANTS IN INDICA RICEITHE PRODUCTION OF HOMOLOGOUS SERIES OF EARLY MUTANTS

The percentage of homologous series of early mutants induced from the same Indica rice variety were almost the same(1.37 % 1.64CX4% )in 19831993,but the ones from the different ecotypical varieties were different.The early variety was 0.73 % ,the mid variety was 1.514% , and the late variety was 1.97 % .The percentage of homologous series of early mutangs from the varieties with the same pedigree and relationship were similar,but the one from the cognation were lower than those from distant varieties.There are basic laws and characters in the homologous series of early mutants: 1.The inhibited phenotype is the basic of the homolgous series of early mutants;2.The production of the homologous series of early mutants is closely related with the growing period of the parent;3.The paralled mutation of the stem and leaves are simultaneously happened with the variation of early or late maturing;4.The occurence of the homologous series of early mutants is in a state of imbalance.According to the law of parrallel variability,the production of homologous series of early mutants can be predicted as long as the parents' classification of plant,pedigree and ecological type are identified.Therefore,the early breeding can be guided by the law of homologus series of early mutants.