Aflp Fingerprints Of Germplasm Material For Rubber Tree (hevea Brasiliensis)

The Rubber tree (Hevea brasiliensis Muell-Arg), a typical tropical tall arbor of genus Hevea of family Euphobiaceae. The natural rubber is an important strategic material in the national economy and plays an irreplaceable role. Breeding good rubber species lays foundations for improving the per unit yield of rubber and promoting the development of relative industries. The genetic basis is getting narrower while little improvement of the productivity from new species is achieved because of long period of hybrid breeding among the related species. Therefore, the genetic basis of new species has to be expanded in order to improve the breeding efficiency and accelerate the breeding of new species, however, the quality of materials, rubber tree species classification, preservation, genetic analysis is a prerequisite for breeding selection.AFLP(amplified fragment length polymorphism) marker shows high level of polymorphism and abundant, strong bands. AFLP's results have excellent stability and reiteration. So AFLP is one of the most effective molecular markers so far. In recent years, AFLP technology is more and more used for forest resources research. By constructing a more stable AFLP silver staining system for rubber tree leaves, determine the best reaction conditions in the test, this research has adopted the technology of molecular marker to study rubber tree by AFLP analysis. We analyzed the genetic relationship and diversity of 188 rubber tree germplasm by AFLP molecular mark technology, and constructed its AFLP fingerprint map. All these is in order to provide the basis for molecular assessment and molecular classification of the rubber tree, to lay the foundation for marker-assisted breeding, and to provide a scientific basis for good use of natural rubber tree resources.The main results are as follows:1. Twentyfive EcoRI/Mse I Primer Pairs showing high level of Polymorphism and stable strong band were selected out from 256 primer combinations and used for further Practical AFLP analysis.1274 bands were scored,701 of which were polymorphic, the polymorpic rate was 55.02%.2. The arithmetical averages (UPGMA) cluster analysis was used to construct the dendrogram of 188 rubber tree germplasm by these 25 primer pairs. With the similarity coefficient criteria of 0.584 these accessions were clustered into 3 groups, in the genetic similarity coefficient of 0.74, the third largest group can be subdivided into five taxa.5 taxa at different similarity coefficient is further subdivided into a number of teams.mean while, the primary dendrogram and genetic relationship analysis were conducted.3. The genetic similarity coefficient of these 188 rubber tree germplasm was mostly between 0.84 and 0.94, accounting for 94.6%. The highest was reached 0.9570815, and the lowest was 0.5164521; This indicated that most genetic differences among the tested rubber tree germplasm materials is relatively small.4. AFLP fingerprints of 188 rubber trees germplasm were constructed,12 of which have unique characteristics, all of the tested rubber tree germplasm materials can be distinguished according to AFLP fingerprints.5. Contrast cluster analysis and pedigree analysis, both the results obtained are consistent, permiting the rubber tree germplasm AFLP fingerprints of the accuracy, reliability and practicality. Fingerprints can be used to germplasm pedigree research in order to polish the database of the rubber tree breeding.6. Although AFLP technology has inadequacies, that is, the higher cost and difficulty of technical operation, AFLP has good stability, reproducibility, and high resolution advantages, it has its advantage in using for rubber tree germplasm to build fingerprints that other molecular markers not compare with.