Selecting And Molecular Biological Appraisal Of Sport Strains For Jinhua Pear

The pear is a plant which belongs to Rosaceae, Pyrus. There are thirty Pyrus plants which are divided into the Asian pear and the European pear in the world. The pears are cultured by 76 countries of the world at the present. China is the primarily pear origin of the world and the mainly producing area of pears. The yield and culturing area of pears in China have been the first place of the world from 1993 to 2002.The production of pear is a large agriculture property in China. The development of the pear property has the important function for adjusting the agricultural producing structure and for increasing the farmer income in the countryside and for strengthening the national economy. The phenomena of pear sports are widespread in nature and produce much spontaneously. Therefore the cultivars or strains can be selected throughworks of investigation and research which are necessary for the demands of international market and the WTO(World Trade Organization). Jinhua pear(Pyrus Brestchneideri Nak cv Jinhua) was selected from the Jinchuan pear in 1959. Now Jinhua pear is cultured by most of pear culturing provinces in China .Especially Jinhua pear has been a main culturing cultivar in Sichuan. Therefore it is a significant research that selecting and molecular biological appraisal of sport strains of Jinhua pear.Several methods were adopted in this research such as the biological examination, the investigating summary, the experiment in the field and analyzing test in the laboratory. The phonological phase and bionomics for 18 sport strains of Jinhua pear were studied in the test orchard. The growing habits and economic characters of fruits were investigated in the study. The biological characters of each strain were appraised with morphology. Their peroxidase(POD) isozymes were also analysed. The extracting method of pear DNA was probed in the laboratory. RAPD(Random Amplified Polymorphic DNA) techniques and the genetic diversity of pear were explored in the program. The work of molecular biological appraisal with RAPD techniques had been done from genetics. The comparison and primarily selection of characters both the phenotype and the heredity for 18 varied strains had been carried out in this research. The followings were the results.(1).Jinhua pear was easy to take place to inherit the variation in the cultivation process. Genetic variation appeared in 18 varied strains of Jinhua in the different degree. The fruit matured period of some variations such as J1 (Jinhua pear No. 1), J3 (Jinhua pear No. 2), J4, J8 was to advance about 10 days, which was a beneficial variation. The fruit shapesof others like JH and Ji6 emergenced several differences which also belonged to the good variation phenomenon. The ideal circular fruit of strains could be chosen from these variations. The better strains were J1, J3 , J4, J8 , Jn , J14 , J16, J18 according to the investigation of morphology and appraisal of POD and RAPD. The biological characteristics of 8 strains were detailed described in this paper. They would be the good materials of selecting cultivars or strains . The rest strains could be the reserve materials for future research..(2). The peroxide isozyme patterns of 18 sport strains for Jinhua pear exsited the certain differences through the POD analysis, which performed both in the quantity and activity of the isozyme . The peroxidase isozyme patterns of Jinhua Pear and its varied strains had four identical basic bands, only some strains increased or decreased one or two weak bands. Strains of J2, J7, J11 , J17 increased A1 weak band. J5 reduced C2 weak band. Jn , J17 reduced A3 band which was weak too. Difference of peroxidase isozyme patterns expressed that the variation of Jinhua sport strains were controlled by the genotype not by the environment.(3). The methods of extraction for Genomic DNA of Jinhua with high quality and high purity indicated that improved CTAB(Cteyltriethylammonium Bromide) was a good method to extract DNA of pears. The appropriate quantity of extracting l...