Study On Main Cultivated Varieties Identification With RAPD Marker Technology

Study on main cultivated varieties identification with RAPD marker technologyGinkgo biloba, a kind of remained tree, is belonged to Ginkgoaceae and Ginkgo. It is wide in its distribution. There are 30 provinces in China existed Ginkgo biloba, except for Hei longjiang and Qinghai. It is pretty well in its nutrition and medicine uses, it is also looked upon as beautiful art in landscape garden. So it is high value in research and exploitation. Now Ginkgo biloba plant area is increasing year after year. For resolving the question of how to precise determine the cloning varieties of Ginkgo biloba, the research on identification of main cultivated varieties of Ginkgo biloba with RAPD is made.RAPD is a kind of molecular marker based on PCR, set up by Williams and Welsh in 1990. It uses lObp random primer amplified the different DNA fragment in genome to show the polymorphism. It is often used configuration method to class the cultivated breeds of Ginkgo biloba and seldom reported with RAPD, which is built the theory on the DNA level. Do this research is not only provide with the scientific and reasonable result to make the agreeable norm in classification study, but also free of the economic loss of productive development.The paper is a part of China State Forestry Administration key subject chaired by professor Tan xiaofeng. The breeds of Ginkgo biloba come from the plant areas in Linan county, Zhejiang province and Dongan county, Hunan province. Altogether there are 17 breeds. They are Jinbingwei, Huangjinwan, Tengjiulang Lingnan, Tancheng number 5, Tancheng number 9, Tancheng number 306. Tancheng Changzi. Tancheng Yuanzi. Foushou in Lingchuan in Guangxi, Taixing in Shandong, Linan in Zhejiang, Dongan in Hunan, Da Meihe, Dongan Meihe, Dongtinghuang Da Foushou, separately. There are six efficient primer selected from 49 primers which is built the molecular genetic linkage map of Ginkgo biloba and use them to identify 17 species each other, then draw the assembling class map of cultivated varieties, the research result is as following:The first part is study on the effect of extraction endosperm DNA with improved CTAB and SDS method. It is showed that improved SDS method spent less time than improved CTAB method. It takes only 5 hours to finish the whole procedure, half day ahead of another. And the DNA concentration is higher than improved CTAB method. But the quality of purity of sample is not better with comparison. RAPD experiment gives a piece of proof that low purity DNA sample gets the same clear fingerprint as the high. Hence, we can draw a conclusion that improved SDS method is feasibly applied in endosperm DNA of Ginkgo biloba. At the same time, the content of protein and sugar is not influenced the result of RAPD. Improved SDS method is first reported here.It has found 49 marker sites with 6 efficient primers by RAPD. Based on it marker genotype is formed and the molecular identification system is established accordingly. 17 main cultivated varieties classified into two groups based on Nei's (1978) Genetic distance. The result is a little different with conventional classification. Probably, it is more scientific to get the truth when configuration character is combined with DNA data. It is needed to do further work to confirm it.