The Effects On The Stone Cell Content Of Dangshansu Pear Based On Genetic Relationships Of Pollination Cultivars By SCoT Analysis

Pear has the obvious phenomenon of pollen xenia and male parent pollination,which may affect the traits of fruit.In this study,a single factor experiment method was designed to optimize and establish a SCoT molecular marker system for pear?Pyrus spp.?.Furthermore,the diversity and genetic relationship of 43 pear cultivars,which were collected from Dangshan,Anhui Province,were analyzed with the optimized SCoT system.8 pear cultivars which had different genetic relationship with Dangshansu pear were selected from 43 pear cultivars.Using qRT-PCR to analyze the influences on the expression of key genes related to lignin synthesis,we discussed the effects of the cross pollination and genetic relationship on the development of stone cell and lignin synthesis,to provide theoretical and practical basis for selecting excellent pollination varieties.The main conclusions in this research were as follows:1.In this study,a single factor experiment method was designed to optimize and establish a SCoT molecular marker system for pear.The optimized SCoT-PCR in pear was as follows: a total volume of 25?L-reaction system including 30mg/L template DNA,1.0?mol/L primer,0.2mmol/L dNTPs,1.0U Taq polymerase,and 2.5?L 10×Easy Taq Buffer(with 2mmol/L Mg²⁺).16 primer combinations were selected from 67 SCoT primers for their abilities in amplification of clear bands with significant difference.A total of 145 bands were amplified,in which 126 bands were polymorphic?86.1%?with 9.1 bands per primer on average.2.The optimized SCoT-PCR system was applied to 43 pear samples.The result showed abundant polymorphism in the tested pear.The value of genetic similarity coefficient was ranged from 0.517 to 0.931,with the value of 0.685 on average.Moreover,the 43 pear varieties could be classified into 2 groups including A and B based on the similarity of 0.690 using the cluster analysis.When the genetic similarity coefficient was set at the value of 0.746,group A could be divided into 6 subgroups.3.At 39 days post anthesis?DPA?,in Dangshansu pear pollinated with 8 pear varieties,the number of stone cells were between12.17¹5.8,among them Dangshansu×Yali's was the most;the area of stone cells were between 22069.43?m²⁴6505.07?m²,among them Dangshansu×Hongjinqiu's was the biggest;the content of stone cells were between 4.438%⁹.454%,and Dangshansu×Yali's was the highest;the content of ligin were between 0.017%⁰.176%,and Dangshansu×Wakahikari's was the highest.At 63 DPA,in Dangshansu pear pollinated with 8 pear varieties,the number of stone cells were between 8.3¹0.5,in addition,the number of Dangshansu×Meigetsu's was the most;the area of stone cells were between 37596.86?m²⁸1260.19?m²,among which Dangshansu×Hongjinqiu's was the biggest;the content of stone cells were between9.298%¹7.197%,and the highest content was Dangshansu×Hongjinqiu's;the content of ligin were between 0.360%⁰.640%,and among them Dangshansu×Hongjinqiu's was the highest.At 145 DPA,in Dangshansu pear pollinated with 8 pear varieties,the number of stone cells were between 1².4,and among them Dangshansu×Whangkeumbae's was the most;the area of stone cells were between 52085.73?m²⁹3752.80?m²,among them Dangshansu× Hongjinqiu's was the biggest;the content of stone cells were between0.327%¹.340%,among which Dangshansu×Yali's was the highest;the content of ligin were between 0.058%⁰.448%,and Dangshansu×Yali's was the highest among them.4.8 different genetic relationship pears to Dangshan pear were used to pollinate with Dangshan Pear.The expression of PAL,C4 H,CCoAOMT,CCR,F5 H,CAD were higher at39 DPA and 63 DPA.At 145 DPA the expression of C4 H and CAD were higher,while CCoAOMT,CCR,F5 H,POD were at a lower expression level.What's more,the expression of PAL showed a higher level only in Dangshansu×Meigetsu and Dangshansu×Whasan pollination combination.The expressions of some key enzyme genes in lignin biosynthesis,such as PAL,C4 H,CCoAOMT,F5 H were higher at 39DPA?early stage of Dangshan pear stone cell development and lignin synthesis?compares to 63DPA?metaphase stage of stone cell development?.The expression of POD at 63 DPA was significant higher in contrast to39 DPA and 145 DPA.