A Identification Of Markers Linked To Tylcvd Gene In Tomato

Tomato is one of the most popular and widely cultivated vegetables in the world. At present, tomato yellow leaf curl virus disease (TYLCVD) is one of the most serious diseases. After tomato yellow leaf curl virus(TYLCV) was first discovered, it spread rapidly in a few years. Therefore, we must take positive and effective measures to control the disease, and developing disease resistant tomato varieties is the most economic and efficient method. In recent years, with the development of molecular biology techniques, molecular markers linked to disease resistance gene were screened, which has great significance for breeding.Study on TYLCVD-resistance gene is beneficial to molecular marker-assisted breeding. In this study, we use "T0727","T9179",F1 and F2 as basic materials, and by using AFLP, SRAP, and cDNA-AFLP techniques, study on molecular markers linked to disease resistance gene. Results as following:(1) Molecular markers of TYLCVD-resistance genes were screened by AFLP. About 30000 polymorphic bands were amplified with 374 primer combinations in "T0727", "T9179", "T07027×T9179" F1, resistance pool (BR) and susceptible pool (BS). Three AFLP markers linked to the resistant genes were obtained, which are E-ACA/M-CAG,E-ACC/M-CAG and E-ACT/M-CTA, genetic distances of theirs are 18.2 cM,9.5 cM and 20.1 cM respectively.According to the screened AFLP markers, primers were designed. AFLP marker E-ACC/M-CAG linked to the resistance gene was successfully converted into a SCAR marker in order to facilitate the practice of molecular marker-assisted breeding, which has high correct rate through the analysis to plants.(2) 340 SRAP primer combinations were applied to screen markers linked to TYLCVD-resistance genes in "T0727", "T9179", "T07027×T9179" F1, resistance pool (BR) and susceptible pool (BS), and 262 primer combinations can amply stable bands, effective rate was 77.0%. One SRAP marker linked to the, resistance gene was obtained. The genetic distance computed from small groups show that the maker may be link to resistance gene. We will validate the marker in F2 segregation population and other tomato materials in further.(3) cDNA-AFLP was used to analysis gene expression profile in the parents "T0727", "T9179" and F1, which induced by tomato yellow leaf curl virus (TYLCV). 64 AFLP primer combinations were used to test expression profile by cDNA-AFLP. Nine differential fragments were obtained from treatment group and control group.The sequences were analyzed in the NCBI database.Five genes have a higher genetic similarity, four fragments did not search for homologous sequences, which may be unknown genes. Function of five differentially expressed genes would be further studied.