Analysis of genetical regulation on crop physiological traits due to the interaction between nuclear and cytoplasmic genomes.

在本项目中，我们采用了分子遗传学和常规遗传学相结合的方法进行研究。在甜菜细胞质雄性不育系中，我们证实线粒体DNA由几个大小类别的圆形分子组成，而N(正常)和S(雄性不育)细胞质中小圆形DNA的数量和大小在0.28um到0.6um之间。高分子量DNA的变异也使我们能够检测到mtDNA的多态性。此外，我们还证明了雄性不育细胞质的分类与常规的育性恢复基因分析的结果基本一致。核质互作在具有山羊草细胞质的N-C杂交种中表现突出。在生长习性、光周期反应、营养期和耐冷性等几个生理性状上，细胞质变异性增加。采用体外筛选的方法分离出对几种除草剂和氯化钠具有特异性抗性或耐性的变异体。利用水稻种子愈伤组织在胁迫条件下进行重复选择，在细胞水平上有效地提高了水稻的耐性。我们还研究了同工酶和株型等遗传标记的基因作用和染色体定位，为形态发生的育种和生理研究提供了依据。

In this project, we carried on a coordinate research by using both of the molecular and conventional genetic approaches. In the cytoplasmic male sterility of sugar beets, we confirmed that the mitochondrial (mt) DNAs consisted of several size classes of circular molecules and N (normal) and S (male sterile) cytoplasms differ in the number and size of small circular DNAs between 0.28um and 0.6um. Variation of high molecular weight DNA also enabled us to detect the polymorphism of mtDNAs. Further we demonstrated that the classification of male sterile cytoplasms are in general agreement with those based upon the conventional analysis of fertility restoring genes in test crosses.Nuclear-cytoplasmic interation was prominent in N-C hybrids of wheat having the cytoplasm derived from Aegilops ovata. Cytoplasmic variability increase in the several physiological traits such as growth habit, photoperiodic response, vegetative period and cold tolerance.In vitro selection was applied to isolate the variants exhibiting specific resistance or tolerance to several herbicides and sodium chloride. The repeated selections under the stressed condition by using rice seed calli were effective in raising the degree of tolerance at the cellular level. However, it is needed to confirm the stable genetic change at the plant level.We also studied the gene action and chromosomal location of genetical markers such as isozymes and plant types for the use of breeding and physiological studies of morphogenesis.