Study On The Morphological Structure Of 14 Bio-type Chionanthus Retusus Leaves In North China And Analysis Of Genetic Diversity

Chionanthus retusus is an important landscaping,ornamental and medicinal tree.Chionanthus retusus in north China were divided into 14 major bio-type based on fast-growing or not,leaf shape,shape of branches,density of branches and leaves angle of branches and bark traits,“Fengyuan Susheng”,“Daye Susheng”,“Daye Yuanguan”,“Xia Ye”,“Dachang Tuoye”,“Gaodajincou Susheng”,“Xiaoye Susheng”,“Zhugan Mingxian”,“Shu Zhizhili Susheng”,“Daye Chuizhi”,“Kaixin Xiachui” and “Mizhi(Quzhi)Jincou”.The morphological and anatomical characteristics of leaves were one of the important basis of plant classification,and molecular marker could reveal the genetic diversity of species.In order to provide basis for evaluation of resources,division of bio-type,screening of variety and genetic breeding,the differences,differentiation of bio-type and genetic diversity among 14 bio-type Chionanthus retusus were studied.The morphological and anatomical characteristics of 14 bio-type Chionanthus retusus leaves were studied by the methods of observation,comparison and statistical;and the molecular genetic diversity of 14 bio-type Chionanthus retusus was studied by AFLP molecular marker.The results showed as follows:1.The significant differences were among the length,width,length/width,length×width and area of 14 bio-type Chionanthus retusus leaves except of the leaf thickness and shape index.Variance analysis and multiple comparisons showed that the p value was less than 0.01,the difference was significant.2.The thickness of leaf,upper and lower epidermal cuticle,upper and lower epidermal cell,palisade and spongy,length of upper and lower epidermal cell,palisade thickness/leaf thickness,spongy thickness/leaf thickness,palisade/spongy ratio,thickness and vessel diameter of main vein of 14 bio-type Chionanthus retusus leaves cross section were significant.Variance analysis and multiple comparison showed that the p value was less than 0.01,the difference was significant.3.The diameter of cross section,distance of epidermis to vascular bundle,vascular bundle thickness,vascular bundle thickness/petiole thickness,thickness of cuticle and epidermal cell of 14 bio-type Chionanthus retusus petioles were significant.Variance analysis and multiple comparison showed that the p value was less than 0.01,the difference was significant.4.One central vascular bundle was in all petioles cross section,but the total and the lateral number of vascular bundles,some were same,some were not.Xylem thickness,phloem thickness,xylem thickness /vascular bundle thickness,xylem thickness/ vascular bundle thickness,xylem/phloem ratio and vessel diameter of 14bio-type Chionanthus retusus were significant.Variance analysis and multiple comparison showed that the p value was less than 0.01,the difference was significant.5.19 traits of the cross section of 14 bio-type Chionanthus retusus leaves and petioles were selected and analyzed by UPGMA cluster analysis.At the genetic distance of L = 4.92,14 bio-type Chionanthus retusus could be divided into three clusters.Cluster ? had 11 bio-type,including “Fengyuan Susheng” ?“Daye Susheng” ?“Daye Yuanguan” ?“Xia Ye” ?“Dachang Tuoye” ?“Gaoda Jincou Susheng” ?“Xiaoye Susheng” ?“Zhugan Mingxian” ?“Shuzhi zhili Susheng” ?“Kaixin Xiachui” ?“Pingzhi Xiachui” and“Mizhi(Quzhi)Jincou”;Cluster? had 2bio-type,including“Guize Yuanguan” and “Daye Chuizhi”;Cluster? had 1bio-type,including“Daye Susheng”.6.Genetic diversity of 14 bio-type Chionanthus retusus was analyzed by AFLP molecular markers.452 bands were obtained,of which 324 polymorphic bands were obtained,and 81 polymorphic bands were obtained from each primer.The polymorphic bands accounted for 71.68% of the total amplified bands.The average number of bands obtained from each group of primers was 100-10000 bp,the bands of obtained ranged(M-CC + B-T-GA)to 154(M-CA + B-T-GG),the mean was 113.The results showed that there was abundant genetic variability among 14 bio-type Chionanthus retusus at the level of DNA molecular polymorphism.7.AFLP fingerprint clustering tree was constructed based on Jaccard's similarity coefficient by DPS.The results showed that Jaccard's similarity coefficient varied from 0.52 to 0.88 and the average value was 0.70.It showed a high genetic diversity.At the genetic distance of L = 0.79,14 bio-type Chionanthus retusus could be divided into four clusters.Cluster ? had 4 bio-type,including “Fengyuan Susheng” ?“Xia Ye” ?“Guize Yuanguan” and “Gaoda Jincou Susheng”;Cluster ? had 3bio-type,including “Daye Susheng” ?“Xiaoye Susheng” and “Zhugan Mingxian”;Cluster? had 2 bio-type,including “Daye Yuangaun” and “Minzhi(Quzhi)Jincou”;Cluster? had 5 bio-type,including “Dachang Tuoye” ?“Shuzhi Zhili Susheng” ?“Dye Chuizhi” ?“Kaixin Xiachui” and “Pingzhi Xiachui”.8.14 bio-type Chionanthus retusus were analyzed by UPGMA based on anatomical structure and AFLP molecular markers,and two clustering trees were obtained.There were some small differences in the results of the two clustering trees,but the overall was basically the same.It showed that the clustering analysis with the similarity of anatomical features was related to the AFLP molecular marker,and this could be used to analyze the genetic identification and differentiation of Chionanthus retusus.