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

本课题采用分子遗传学和常规遗传学相结合的方法进行了协同研究。在甜菜细胞质雄性不育中，我们证实了线粒体DNA是由几种大小的环状分子组成的，N（正常）和S（雄性不育）细胞质中的环状小分子的数量和大小在0.28 μ m和0.6 μ m之间。高分子量DNA的变异也使我们能够检测mtDNA的多态性。进一步证明了不育胞质类型的划分与常规测交恢复基因分析结果基本一致，卵山羊草细胞质的核质互作在小麦核质杂种中表现突出。在生长习性、光周期反应、营养生长期和耐寒性等生理性状上，细胞质变异性增加，通过离体筛选，筛选出对几种除草剂和氯化钠具有特异抗性或耐受性的变异体。水稻种子愈伤组织在逆境条件下的反复选择，在细胞水平上提高了抗性程度。同时，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，为育种和形态建成的生理研究提供依据。

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.