Research Of CMS Lines1193A With Sinapis Arvensis L Cytoplasm

Cytoplasmic male sterility (CMS) is most main pathway for rapeseed heterosis utilization. Creation of new CMS and improve the stability of male-sterile lines is the imperative of heterosis utilization in rapeseed, and is also important to sustainable de velopment of hybrid rapeseed germplasm resource base. Using distant hybridization for obtaining heterologous CMS line is the effective means of discover new type CMS line and improving male-sterile stability.Xinjiang wild rapeseed as the female parent, XiangYou15as the male parent, intergeneric hybridization produce a sterile plant for research materials, on which a series of studies are carried out. The work accomplished and the results obtained are the following:(1) Through testcross between sterile material and XiangYou15inbred lines to acquire CMS lines which have infertility rates in100%, then fertility observation and identification of three years and six generations show fertility of CMS line1193A is stable and complete, and maintainer1193B maintain the sterility of1193A steadily, sterile rates reaching100%.(2) By self isolation and testcross sterile identification, restorer lines1193R1is bred from its sister lines fertile plant which can recover fertility of1193A CMS steadily. Through extensive testcross, the fertile plant is found in F1generation of1193A CMS and early materials of Brassica napus, then by self isolation and testcross sterile identification, restorer lines1193R1is bred which can recover fertility of1193A CMS steadily. Genetic analysis indicates that the restoring gene of1193A CMS is controlled by a pair of dominant major gene. Allelism test shows the restoring gene in the restorer lines1193R1and restorer lines1193R2are non-allelic.(3) Artificial pollination can get seed with the rate of seeded siliquae more than89%, and natural open pollination is good, but no siliquaes are found in the self pollination plants. Identification of pollen vigor indicates no pollen grains are found in the anther of1193A CMS, however, strong vigorous pollen grains are detected in the maintaining line、restoring line and hybrid Fl whose pollen stainability are more than92.73%, same as the normal pollen. Except1193A CMS, others have pollen germination ability and the pollen tube can germinate normally. The aver-age length of tetradynamous in1193A CMS is3.77mm, which is significantly shorter than the maintaining line、restoring line and hybrid F1, moreover, Four strong stamen and pistil length ratio is less than one-second which suggests the male sterility of1193A CMS is complete and have significant Sterile trait. All F1generation from testcrosses using restorer and maintainer lines of pol CMS showed100%sterile plants indicating the1193A CMS was different from pol CMS.(4) Analysis on isozyme electrophoresis show different isozymes have similar enzymes bands patterns in male sterile lines and maintainer lines, but the isozymes activity show significant difference at different developmental stages of bud. In POD isozyme, the fastest relative mobility(Rf) is the Rf=0.83band in the1193A CMS which is not detected at early developmental stages of bud, but activity of this enzyme display Significant increase in later developmental stages and its activity is significantly stronger than the maintainer1193B.Moreover, big bud stages of1193A CMS shows stronger activity than middle bud stages in Rf=0.39and Rf=0.49bands, but the POD activity of1193B have not changed. ATP isozymes activity weakened with the development of flower buds, and it mainly in middle and late bud development, in particular, emerging in late bud development of enzyme deficiency, ATP enzyme activity has been detected less, however,1193B has no changed. EST isozymes activity in1193A is lower than1193B. Early bud development, stages, EST enzyme has high activity in1193A, but declined significantly in the late development stages, but1193B have little change in enzyme activity.1193A and1193B have the differences in the intensity and number of enzymes. Based on this point, it may be difficult to determine their association with male-sterile gene expression, but they must plays an important role in male sterility.(5) Analysing the results of paraffin section indicate anther development of1193A start to present abnormal changes after the microspore are released. The tapetum appeared radial swelling and vacuolaltion, and degradation of the disintegration is delayed. Pollen grain also appear vacuolaltion and degradation of nuclear and cytoplasm, till complete disintegrationand. Finally anther occurs shrinking and distortion, and anther cells just have no residue of cell structure.abortion stage of1193A occur at mononuclear pollen stage, belonging to the mononuclear pollen abortion classes. (6)Building a F2mapping populations With sterile line1193A and restorer line1193R2for parents, the study screens1521SSR primers via BSA way,and find8pairs of primers link to restore gene, of which CB10316and BnGMS171are closest to restore gene, and genetic distance is3.9cM and5.7cM respectively. Moreover, Two marker are separated by9.6cM on both sides of restoring genes, considering the two markers as the candidate markers of restorer line for marker-assisted breeding.(7) SNP chip analysis suggests that the two markers which may link with restoring gene adjacent to the PPR gene. Multiple PPR proteins genes also are found in the target area of C09chromosome.we Speculate that the restoring gene of1193A CMS may exist on the C09chromosomes and it may be PPR protein gene.