Studies On The Identification And Analysis Of Radish Cultivars Resistance To TuMV Using RAPD And Isozymes

Using the RAPD and isozyme technique, Radish varieties resistance to TuMV were studied, the result showed: Eleven radish varieties resistance or susceptible to TuMV was identifi edby inoculating with TuMV in cotyledon stage .the radish varieties Rebai radish,Qiukuiqing and Yadantou showed high resistance to TuMV and their disease index were 2.0,0,and 1.2 respectly; while Yanghua radish, Xiachangbai and Nanyan 30 days were susceptible with disease index 35.2,40.6 and 52.1. The results showed coincidence with field identification. 2 RAPD technology was employed to aanalyze genome DNA of eight radish varieties resistance or sensitive to TuMV.The study chose 30 random primers and six of them had polymorphic products.According to the hierarchical cluster method, we found that the varieties in a group were related to their resistance to TuMV. In addition ,following the approach of bulked DNA method, primer S359 seems linked to the resistance.This work has provided a solid basis for the radish breeding and the location of resistant gene. 3 The DNAs of Wanhong (the resistant parent),Yanghua radish(the susceptible parent) and their Fl hybrid were detected with 30 primers. The result indicated that the primers S353 ,which showed codominance in FI,could be used to distinguish two parental lines and their F1.At the same time we studied the profile of EST isozyme, The Fl showed the same profile with the resistant parent. Using the RAPD and isozyme technique we can identify and detect the purity of Fl hybrids in radish. 4 lsozyme ,the production of gene expression ,directly relating to disease resistance ,can be used in the disease resistant study.The activity of three enzymes and the profile of four isozymes were compared among radish varieties with different resistance to TuMV. The result showed the polyphenoloxidase(PPO) activity in leaves was positively related to the resistance to TuMV and can be used to scaled the TuMV resistance.The increasing of EST bands after inoculation in resistant radish can be used as a useful marker for disease resistant breeding. The changes of POD only reflected the physiologic change in radish leaves, hard to be used in the identification of TuMV resistance.