Genotypes Polymorphism And Identification Of RAPD Markers Linked To Sclerotinia Sclerotiorum Resistance In Brassica Napus

In this study, 23 lines derivated from 84004 and some other genotypes of I3rassica napus were used for polymorphism research. Identifying DNA markers linked to the Sclerotina sclerotiorum resistance gene in B.napus used Random Amplified Polymorphism DNAs (RAPD) was explored. The main results are as follows: (1) RAPD and dendrogram analysis showed genetic relationship among those lines. The same origin of different genotypes ,although the obvious difference of agronomic characters, the relation of these genotypes could be identified by RAPD analysis. The results indicated that RAPD technique was a valuable and reliable method to classify rapeseed varieties. (2) By utilizing RAPD, a DNA fingerprints was constructed by screening with 200 primers. Only primer S 1095 could distinguished 7 of all the 23 genotypes form each other and all the genotypes could be distinguished with primer S 1095 and S2054.Therefore, the results showed that the RAPD can be used for identification of seed purity and varieties. (3) RAPD was used with the objective of identifying DNA markers linked to the S.sclerotiorum resistance of B.napus. Bulked segregant analysis(BSA) was used to detect polymorphism that should be linked to S.sclerotiorum resistance. Two bulks were made by pooling previously extracted DNA, each bulks (one resistant, and the other susceptible) consist of 4 genotypes from an F2 population obtained form a cross between 78 3-3 and 84039. By screening 420 random primers, one resistance RAPD marker of S204650 was found. (4) Researchers working on molecular markers always pay attention to the stability of RAPD. In this study, the relevant conditions of RAPD wereanalyzed, the quality of template could affects the RAPD profile besides theconcentration of Mg'+ and dNTPs .the results suggest that template shouldbe dissolved in pure water. What's more, for different random primers havethe different number target sequences in the same template, by adjusting theration of primers and template could obtain good results.