Genetic Diversity And Fingerprinting Of Hybrid Parents In Brassica Napus L.

Male sterility is an important way to utilize heterosis of rapeseed. In the breeding ofhybrids, how to choose parents is a key step to gain strong heterosis and efficient use ofheterosis. It is helpful for selecting parents and forcasting prospect of breeding to clearlyknow relationship, pedigree derivation, genetic diversity and genetic distances of the usedparents.China is the first country to produce hybrid of rapeseed practically in the world. PolCMS system is the main type in hybrid production. However, pol CMS is easy to havetrace pollens when flowering in low temperature. During hybrid production, a trace ofpollens of sterile lines for its incomplete male sterility or the effect of temperature orphotoperiod will produce sterile plants in F₁ population. High proportion of male sterileplants in F₁ will affect hybrid yield. For commercial seeds, hybrid plays an important rolein seed trade. In seed market, some people sell adulterated or inferior seeds and evenillegally gain hybrid parents to produce hybrids. All these actions severely damage thelawful rights and benefits of the breeders or legal companies. Therefore, how to protecthybrid parents and identify hybrid purity becomes more and more important in hybridproduction and commercialization.Genetic diversity of hybrid parents in Brassic napus was evaluated with molecularmarkers so as to make clear of their relationship, pedigree and genetic distances and offertheoretic reference for breeding. Meanwhile, DNA special fingerprint of hybrid parentsand variety were constructed, and convert them into SCAR markers so as to providemolecular testimony and means for protecting hybrid parents.The followingis the mainresults:1.63 SSR primers screened from 200 SSR primers were used to analyse the geneticdiversity of 101 Brassica napus including 33 male sterile lines, 51 restorer lines, 6maintainer lines and 11 cultivars. 261 polymorphic bands were used for clusteringanalysis with UPGMA. 101 Brassica napus were classified into 7 groups. All sterile linesexcept P61-2,P-49,P-48,8-829,8-430 and Yu105 were clustered into Groupâ… -â…¢andrestorer lines into Groupâ…£-â…¦when threshold value was 0.2257. These results indicatedthat restorer lines had more genetic diversity than sterile lines and genetic distancebetween the sterile lines and the restorer lines was larger than that among the sterile linesor among the restorer lines.2. DNA fingerprints from101 Brassica napus were created with 15 SSR primers.3. DNA special fingerprints of 28 parents were got by amplifications with AFLPprimers. SA01/TG04 can only amplify a 275 bp band to P61-8 and the special fragmentwas successfully converted into dominant SCAR markers. Amplifications were doneonce more among two parents (Yu102 & P61-8) and F₁ individuals. Specific bands tothe father were produced by SC02 in F₁ plants. This result indicated that SC02 couldbe used to detect seed purity of a hybrid easily.