Application On The Genomic Variety And Germplasm Resources On Gansu Peach Using RAPD Markers

Peach (prunus persica L Bastch), originating from the western of china, is one of the most ancient fruit. It has more than 4000 years in China and distributes extensively. Peach has developed many species and categories in the long period of natural selecting and artificial domestication. The statistic amount of peach species in our country is about 800, and occupie 27% of that in the whole world. 　Gansu province is one of the fittest and most original areas of cultivated peach. There is favourable climate for peach planting, which is characteristic in sufficient sun, fewer rain, bigger temperature difference in a day,dry weather and fewer plant diseases and insect pests. Therefore, developing characteristic peach industry has great foreground in Gansu. But due to peach's sensitivity to environment, clear regional distribution of cultivating, short and concentrative mature period and soft and putrescible pulp, which lead to the difficulty for sale abroad. So the economic benefit is lower, and the study in breeding and planting peach is comparatively backward in our province. The paper based on the survey of peaches in Gansu, aimed to find out the application of RAPD in identifying peach species, analyzed the genomic diversification in peach through RAPD, and determined the types, distribution and characteristics of peach in Gansu. So we can prevent from the fake saplings , establish super peach breeding system to offer the theoric and technological guide for the regionalization of peach cultivating and the development of local feature peaches. The main results as following: ( 1 ) There were 30 peach species which have been analysed and classified by their physiologic specific property in the trial, and found Gansu province is favorable for peach planting. There is 10% of peaches originating from Gansu, about 16.7% of that from foreign and most of that from other internal places. ( 2 ) Study on the peach genomic DNA collecting was done with three kinds of methods which were CTAB, SDS and Substep centrifuging method. As a result, the most appropriate method is Substep centrifuging method and improvement was done with PVP,Vc etc inside, which can efficiently prevent the oxide of phenol matter that can create the genomic DNA colleting difficulty in forming. At the same time, found that the purity of DNA gathered from the young tender leaf is the highest at 7:00-8:00am. ( 3 ) Established one set of serviceable RAPD's technology system, and amplified the genomic DNA of 44 peaches by using RAPD, the number of DNA bands was between 3-13, the molecular weight of them was concentrated between 250bp-3500bp. 233 DNA bands were amplified in total,156 of that were polymorphic(67%),showed that there have quite high genetic diversity. (4)A tree diagram was constructed by using SPSS method. All the materials were taxonomied into 7 typies: among them, Dongshu is a breed improved in Gansu province and is one kind of extremely late-maturing breed, its inheritance with other breeds relation is far away, and can be divided into one kind alone; Dajubao, its 7 relative breeds and breeds such as Zaoxialu, Chunlei and Ribenhong, ect totally 14 breeds are for one kind. And Beijing 15 , Chongyanghong, Hongxuetao, Qiuyu,Beijing 7 and Qiannianhong are for one kind; Zaomei and Zaolupan assemble for one kind, and Zhubo84 and Longmi 9 are assembling for one kind; Chuizhitao,Ganxuan 3 are for one kind explained that regional difference is not notable. Peach of Gansu province and ornamental peach is drawn for a level, and is in the more original position,; All the other 17 breeds are assembled for one kind, accounted for that the southern peach ( Central China ecotype ) and northern peach ( North China ecotype ) as well as American oil peach are in one kind of evolution position of close to parallel. ( 5) The result showed that most peach species of Gansu Province are middle and late mature ,the extremely early and late mature species of high quality are less.At the same tine,there are some other kinds of peaches , like the flat peach, yellow meat peach and ornamental peach, which are very few and should be imported in quantity to enrich its diversity. At the same time, we can cultivate earlier and later species by adopting cultivating equipments to develop the characteristic peach in Gansu.