System Establishment And Application Of AFLP Technique In Pyrus L.

AFLP marker is a new kind of technique, which is widely applied in the molecular biology, high mammal and plants in recent years. The fingerprinting analysis based on AFLP was carried out in 44 different pear cultivars, including six pairs of sports. This study aimed at discussing the feasibility of AFLP applying on Pyrus germplasm, which could find out the ownership of some cultivars, such as Pingguli pear and so on. The main results were as follows:1 Some factors affecting establishment of AFLP technological system have been tested and analyzed again and again, and at last a most effective system was established. Some improved factors were as follows: (1) the concentration of template DNA was ISOng/^L, the template DNA dosage was 450ng; (2) in the digestion system, each of Msel and EcoRI was input SUnits, Msel Buffer was used and reaction time was 5 hours; (3) the most available ligase dosage was 1.5U, the reaction time was 10 hours; (4) the products of ligation was diluted to 5 times for preamplification; (5) the products of preamplification reaction was diluted to 5 times for selective amplification.2 10 pairs of primers selected from 64 primer combinations were identified to be high polymorphic and were applied on AFLP amplification in 44 Pyrus plants. 371 loci were gained among which 306 loci were polymorphic. Average locus numbers amplified by per pair of primer were 37.1.3 The fingerprinting pattern based on AFLP was preliminarily established. The identification efficiency of 10 pairs of primer differed from each other, among which My/Es was able to distinguish 44 pear cultivars.4 19 forms had specific AFLP markers which were 48.2% of the total.5 On the base of AFLP data abtained from the study, clustering analysis on the 44 materials of pear were carried out, and the tree diagrams were established by ward's method, the relationships within different systems of Pyrus were discussed.6 The existent demurral on systematic status of Pingguoli pear was discussed, Pingguli pear clustered together with Jinhuasihao pear which belonged to Pyrus bretschneideri, so we considered that Pingguoli pear should belong to white-pear system.