The Establishment Of AFLP Fingerprinting Of Pears

Pears come from China.The resourse is abundant,has many varieties in China.It's necessary to classfy and analyze the relationship between the different varieties in heredity. Pyrus. L germplasm's identification, especially the excellent cultivars, is the base for fruits breeding and the precondition for developing production.DNA molecular marker is a strongly tool for Pyrus. L germplasm's identification in molecular level. 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 the most effective moleculai marker so far. This study applies the normal system,establishes 73 pear cultivars' fingerprinting and analysized the genetic diversity. The main results are as follows:1. The genomic DNA of pears are extracted by a modified CTAB method effectively. The DNA gained by this method have high concentration, no degradation. The protein, amylase and RNA are wiped off drastically. The purified DNA are suitiable for AFLP analysis.2. 8 pairs of primerd are applied on AFLP selective amplification in 73 Pyrus plants. 447 loci are gained among which 376 loci are polymorphic. The genetic distance of 73 pears plants are between 6.93 and 14.66. All of this reflect the genetic diversity among pears' gene.3. The fingerprinting based on AFLP is preliminarily established. 4 cultivars have specific AFLP bands which are 5.48% of the total. 15 cultivars have different AFLP bands which are 20.55% of the total.4. Genetic relationships tree diagrams are established based on the genetic diversity of 73 germplasm of pyrus. L. These germplasm can be separated into 2 groups by ward's method. Their genetic diversity are discussed.