Analysis Of Variation Of Pear Germplasm Accessions By SRAP And EST-SSR Markers

China is the origin center of genus Pyrus. There are13Pyrus species originated in China withabundant germplasm resources. This experiment identified four pairs of pear bud mutations and13pears accessions of Liaoning Suizhong County using SRAP and EST-SSR molecular markers. Mainresults are as follows:1. Four pairs of bud mutations:‘Pingguo pear’ and its mutation,‘Qiuzi’ and ‘Sweet Qiuzi’,‘Lanzhouchangba’ and ‘Lanzhouhuachangba’,‘Kuerlexiang pear’ and ‘Sha01’, were identified usingSRAP and EST-SSR molecular markers. A total of62DNA bands were amplified by5primers selectedfrom100primers, of which53(83.9%) were polymorphic, showing a high genetic diversity existed inthe individuals. UPGMA analysis indicated that9genotypes were categorized into2groups and4subgroups. Dice Similarity coefficient of8genotypes ranged from0.536to0.985. The results showedthat SRAP can be used to identify pear bud mutation.10EST-SSR primers didn’t produce any specificfragments and could not distinguish the4groups of mutations.2. SRAP molecular markers were applied to identify the mutations and analyse phylogeneticrelationship of ‘Suizhongxiehuatian’,‘Fenhongxiao’,‘Shuihongxiao’,‘Yanghongxiao’,‘Qiubaipear’and its8suspected mutation individuals. A total of76DNA bands were amplified by9primersselected from100primers, of which43(56.6%) were polymorphic. NTSYS-pc2.1clustering softwarewas used to analyse the9primers’ amplification results. The materials were categorized into2groupsand4subgroups. Dice similarity coefficient ranged from0.69to1.00. Four primers me2/em1, me4/em1,me4/em6and me7/em1can be used to distinguish the tested materials except the suspected ‘Qiubaipear’ mutation No.1, No.5, No.6, No.8, and No.9. Suspected ‘Qiubai’ pear mutation individuals, No.1,No2, No4and No7, showed differences at some SRAP markers.3. EST-SSR molecular markers were used to identify the parents of individual No.7. It inherits oneof the alletes of ‘Qiubai pear’ at all of the9loci detected in this experiment and might have ‘Qiubaipear’ as one of its parents.‘Suizhong xiehuatian’,‘Shuihongxiao’ and ‘Yanghongxiao’ were denied asits parents. More pear cultivars should be used to find out another parent of No.7.