Application Of Apple Ssrs In Genetic Relationship Of Pyrus

In this paper'Jinhua'(Pyrus bretschneideri)'was primary taken as representative Chinese pear of Sichuan province in China to compare genetic map of apple and pear (P. communis, P. pyrifolia, and P. bretschneideri), and to compare the genetic map of'Mishirazi'to P. pyrifolia and P. communis. The apple SSRs mapped in 'Mishirazi'and'Jinhua'were evaluated in polymorphism. The high representative and polymorphic SSR markers were chosen for further genetic classification of Pyrus, cultivar and mutant identification. The main results are as follows:①In 101 apple SSR markers, twenty-three were no amplification, and seventeen were no segregation in'Mishirazi','Jinhua'and their four progenies; eleven were complex segregation in'Mishirazi','Jinhua'and their sixty-two progenies; twenty-two were no linkage relationship and twenty-eight were linked in'Mishirazi' and'Jinhua'.②wenty-four and fifteen apple-mapped SSR markers showed linkage relationship in'Mishirazi'and'Jinhua'respectively. Genetic linkage map segments of these 2 pears were aligned by 10 co-dominant markers that showed segregating alleles in both parents, separately distributed in linkage group segments 9,11,14 and 17. And apple SSRs were more preferable to transfer and conserve to'Mishirazi'than'Jinhua', speculating that'Mishirazi'inherited slightly more features from its male parent, grouped it in P. communis.③he'Jinhua'was primary taken as representative Chinese pear to compare genetic map of apple and European pear (P. communis), Japanese pear (P. pyrifolia) and Chinese pear (P. bretschneideri).The alignment of the species maps based on JoinMap analysis made it possible to verify the degree of synteny between the apple and pear genomes. The apple SSR loci showed the same order and corresponding distances in the pear and apple maps, strongly suggesting the presence of highly conserved regions between the two genomes, and that apple SSRs were more preferable to transfer and conserve to European pears than Asian pears. The most conserved segments of linkage group between apple and pear were located in LG 9, LG 11 and LG 14 relying on 101 apple-mapped SSRs. The SSRs in LG 10 and 12 wouldn't like to link each other in the cultivar of P. bretschneideri in China and P. Pyrifolia in Japan, respectively.④he relationship compared'Mishirazi'to P. pyrifolia and P. communis was investigated using comparative mapping and phylogenetic clustering. And the results were got that'Mishirazi'showed closer relationship to P. communis.⑤n the twenty-eight apple SSRs that mapped in'Mishirazi'and'Jinhua', the former ten order of polymorphism was CH04al2, CH05d04, CH05g11, CH05c07, CH04d02, CH04f06, CH04h02, CH01f03b, CH03d02 and CHOlh01 from the allele numbers, heterozygosity and Shannon's Information index, which located in linkage group 9,11,12,14 and 17. The ten high representative and polymorphic SSR markers were chosen for further genetic classification of P., cultivar and mutant identification.⑥'Zaoqihuang','Shibaosheng'and'Eli 1'were classified in P. pyrifolia; 'Nangongci','Hongchangqing','Eli 2'and'Zhonghuayuli'were classified in P. bretschneideri;'Chuanxia','Zaosu'and'Mishirazi'were classified in P. communis. 'Pingguoli'was classified in P. ussuriensi.⑦ny pair of individual SSR primers was not able to distinguish'Nijisseiki' related group. It's required that two or more than two markers had to meanwhile work. Similarity coefficient of'Nijisseiki'related group was from 0.84 to 0.95. Systematic tree could be divided in 5 groups.⑧en pairs of SSR primers were used in four pair mutant cultivars and one pair of sister cultivar, which could produce more and clear fingerprint polymorphism (allele), in which CH03d02 could identify all the ten cultivars, which showed good distinguishing ability.