Characteristics Of Different Cytoplasmic Male Sterile Lines Of Rice

Now many types of male sterile cytoplasm, including wild abortive type (WA type), dwarf abortive type (DA type), hong lian type (HL type), bao tai type (BT type), dian type (D type), gang type (G type) and India water type (IW type), have been discovered in the research on cytoplasmic male sterile (CMS) line of rice. It has been proved widely that cytoplasmic types are different in fertility response. The major problems such as single male sterile cytoplasm (BT type), low out-crossing rate, and low seed production have been plagued the development of Japonica hybrid rice in northern China for a long time, so to explore new male sterile cytoplasm is the focus of japonica hybrid rice breeding.In this paper, with two sets of CMS lines from Rice Research Institute of Liaoning Province with different male sterile cytoplasm (MSC) type (WA type, HL type and IW type) and same nucleus, Liaojing6A and LiaojinglOA, three retainer lines including Liming, Liaojing9 and Tijin, and three restorer lines including C418, Fuhui838 and Yejinghui, as materials, the difference in morphological characteristics, flowering habit, and out-crossing characters among MSC types; the restoring and retaining relationship for different MSC types and the combining ability of parents in agronomic traits were analyzed by incomplete diallel cross method between sterile lines and retainer lines and restorer lines respectively; in order to discover the prospect of the MSC type of WA and IW used in Japonica hybrid rice. The results were as follows:1. The three types of CMS lines were different significantly in flowering habit. The WA type and the IW type flowered earlier and more scatteredly than the BT type, the BT type was on the contrary. The IW type was between the WA type and the BT type by the flowering habit, but its stability of fertility was better than the BT type. Therefore, it may be a good solution to the problem that the flowering time of restorer line can't meet that of sterile line in the production of japonica hybrid rice at present.2. The three retainer lines had good retaining ability to all the three types of MSC, that is, to the three types of MSC, the retaining relationship was the same, but the retaining ability was slightly different. Different restorer lines were different in restoring ability to different types of MSC. The same restorer line had different restoring ability to different MSC types, and different restorer lines were different in restoring ability to the same MSC type. The different types of MSC were different obviously in genetic effects, and the genetic effects were mostly negative effects.3. The results of variance and combining ability analysis to thirteen main agronomic traits showed that the differences in all the traits among combinations were extremely significant; the general combining ability variances and specific combining ability variance of parents were reached the significant level in all the agronomic traits, the difference in the specific combining ability among different combinations or among different traits was significant, for a combination, the general' combining ability was not entirely corresponded to the specific combining ability, they were both correlated and independent to each other.