Preliminary Screening AFLP Markers Linked To Green Stripe Traits Of Fruit In Xinjiang Melon

Melon (Cucumis melo L.) is distinctive as a major economic crop in Xinjiang. Xinjiang melon enjoys a good reputation by its unique flavor and excellent quality in the world. Xinjiang has rich germplasm resources. The most important link in the production of Xinjiang melon is breeding fine varieties. Traditional breeding methods have long cycle and heavy workload, and can not meet the present production needs. But the formation and applications of molecular marker techniques provide a new way of thinking for speeding up the breeding process. It will be nicety and speediness using molecular markers linked to the genes of important agricultural traits, and it will help the work of breeding and gene cloning. The establishment of molecular marker techniques which are appropriate for Xinjiang melon and platform of molecular marker-assisted breeding has significance for breeding, genetic map constructing, gene localizating and gene cloning.Nowadays, the researches are less about molecular markers for agricultural traits in melon. In this paper, an AFLP (amplified fragment length polymorphism) analysis system for Xinjiang melon was established by optimizing some key factors, and then AFLP markers linked to green stripe traits of fruit in Xinjiang melon were screened preliminary. The main results were as follows:1. Via repeat experiments, the modified CTAB could be used for extracting genomic DNA which has high quality and is suitable for AFLP.2. By the research of digestion time and dilution times of each step, the AFLP silver staining analysis system for Xinjiang melon was established. The double enzyme digestion should be complete, 300ng genomic DNA was digested with 3U of EcoR I and 3U of Mse I at 37℃for 5 hours; the digested-ligated DNA fragments were diluted (10 folds) then used as templates for pre-amplification, and the products of pre-amplification should be diluted 75 times then used as templates for selective amplification. This analysis detected polymorphism with 6% denaturing poly-acrylamide gel electrophoresis and silver staining. 3. This study has analyzed AFLP polymorphism of two lines (k4-13 and k4-15) by using 64 pairs of selective primer combinations. By statistic there were 3622 bands in which there were 881 polymorphism bands. The rate of polymorphism was 24.3%. The result showed that 14 pairs have produced clear bands and represented rich polymorphism.4. Screening AFLP markers were studied among F2 segregated population originating from a cross between k4-13 and k4-15. Six AFLP markers linked to green stripe traits of fruit in Xinjiang melon were acquired by using BSA. This research has supplyed a gap of molecular markers for melon in Xinjiang, and has founded an important technology platform for molecular marker-assisted breeding in Xinjiang melon, has guiding significance to Xinjiang melon breeding. This would have laid a foundation for the clone and application of functional genes, the construction of genetic map and the research of genetic diversity. So it would be able to speed up the molecular breeding process and have had theoretical significance and important value.