Studies On The Breeding And Utilization Of Early Indica And Good Quality Rice Cytoplasmic Male Sterile(CMS) Line Qiu-xiangA

In order to breed a new CMS line,elite maintaining parents from home and abroad including Jing23B,Xiang 2 B,American rice,,Xiang 5B,Wei20 B were used to conduct multi-hybridization to produce a new maintaining line.Then,a new CMS line named Qiu xiang A with high-quality was developed from testcross and successive backcross with Xin xiang A.Qiu xiang A,Jing23A,Xin xiang A,T98A and their maintaining lines and Ming Hui 63 et al.,six mid-season restorer lines were used to produce 24 combinations and used for materials in this expreinment.The main characteristics and reproductive technology and combining ability of main agronomy characters were studied.Main results are as follows:1.Qiu xiang A shows a complete and stable male sterility and high outcrossing rate.It shows 100%of sterile plants and pollen sterility includeing 97.76%of typical sterile pollen and 2.24%of rounded shaped sterile pollen and 0%of selfing seed setting,stigma exposed rate of 83.87 percent matching with Jing 23A,10.61 percentage points and 8.22 percentage points higher than Xin xiang A and T98A respectively,bilateral exposed rate slightly lower than Jing23 A and higher than Xin xiang A and T98A,stigma vitality matching T98A and stronger than Jing 23 A and Xin xiang A.It has bigger angle spikelet and flowering a long time.The flowering rate before noon is as high as 73.46 percent.It is quite sensitive to "920" and sprayed about 13 g/667m~2 can be completely to lift its neck package.2.Qiu xiang A has good agronomic traits and susceptible to rice blast and bacterial leaf blight disease.It is a late maturity type of early season indica rice, sensitive to temperature and resistant to heat,days from seeding to initial heading longer than Jin 23A 7-9d,and the main stem leaves more than Jin 23A 2 leaves.It has about 70 cm of plant height,good plant type,dark green color leaves,no premature senility and strong tiller ability.It has spikelets about 110 per panicle, slender type grains and 25g of 1000-grains weight(Qiu xiang B).Its grains is of high quality and aromatic.The Qiu xiang A graded in the leaf blast resistance of 8 class, the neck blast resistance of 9 class and bacterial leaf blight of 7 class.3.Qiu xiang A can get a higher yield of propagating and hybrid seeds.After many years of experiments and survey of yield,the outcrossing rate of Qiu xiang A was more than 50 percent generally,and yield of propagating and hybrid seeds about 200 kg/667m~2.4.Qiu xiang A has good combining ability(including general combining ability and special combining ability)in grain weight per plant and other agronomic traits.To analyze the combining ability xiang A,Jin 23A,Xin xiang A and T98A were crossed with 6 mid-season restorer lines(includeing Ming Hui 63).The results showed that hybrids of Qiu xiang A has positive relative value of GCA in grain weight per plant,1000-grains weight,seed setting rate and panicle number per plant,but negative value in spikelet number per panicle,filled spikelet number per panicle,plant height,panicle length and growth duration.From which,hybrids of Qiu xiang A have more effective panicles,greater1000-grains weight,higher seed setting rate,but less number of spikelets and filled spikelets per panicle,shorter panicle length and plant height and growth duration.It also means hybrids of Qiu xiang A can get greater grain weight per plant and yield potential.From the relative value of SCA,Qiu xiang A/R471,Xin xiang A/R198,Xin xiang A /R388 and T98A/R321 have greater values of SCA(all above 10.01),which means Qiu xiang A can also be used to produce hybrid combinations with strong heterosis,furthermore with shorter plant height and growth duration and more effective panicles.Therefore,hybrid combinations of Qiu xiang A have greater yield potential and broad prospect of utilization.