Study On The Genetic Diversity Among Loropetalum Chinense Var.rubrum Introductions And Changes Of Physiology And Biochemistry During Its Leafcolour Transformation

Study on the Genetic Diversity among Loropetalum Chinense var.rubrwn Introductions and Changes of Physiology and Biochemistry during its Leafcolour Transformation Abstract LoropetalumChinensevar. rubruwis an evergreen shrub that belongs to Hawawelidaceae and has many desirable landscape characteristics. It is fast梘rowing, tolerant to disease and insects, and produces an abundance of attractive pink flowers and colored leaves. Recently, the horticultural community has shown an increase interest in this species. It can be used as potted landcape and gardening plant to beautify our environment, and exported to many Asian countries and districts for foreign currencies. Its natural range is only in Liuyang,Hunan province.Since it was first discoveried in Liuyang Dewei mountain, gardeners and researchers have made great effort in propagating this species successfully through grafting, cutting and tissue culture.At present,the study on L. chinense var. rubrwu is only in its very early stage. But in the United States of America, many materials of L. chinense var. rubrwu have been collected from China and selected and registered two cultivars in 1993. This research used both morphological characteristics and Random Amplified Polymorphic DNA(RAPD)to exam the genetic diversity of 14 L. chinense var. rubrum accessions,and 2 accessions of L.chinense.Meanwhile, the changes of physiology and biochemistry during its leafcolour transformation, Chloroplast ultrastructure and anthocyanin stability have been studied . It is the first time that L. chinense var. rubrum has been studied systematically and overally. Now the major results studied in this paper are abstracted as follows: III 1. 14 L. chinense var. rubrum accessions are collected, coded and planted in ornamental plants garden of Hunan Agricultural University 2. At the first time, we used both morphological characteristics and Random Amplified Polymorphic DNA(RAPD) to examine the genetic diversity of 14 L. Chinease var. rubruw accessions and 2 accessions of L. chinense. The latter method is more accurate, but more expensive. 3. The first time, we identify that L. Ghinense var. rubrum is a variety of L. Chinense at the molecular level. According to the RAPD data, the genetic distance between L. Chinense var. rubruin accessions and L. Chinense is 0. 42?. 46. We use 0.50 (genetic distance) as the standard to indentify species according to Chen Xin梟ian?s study. 4. 14 L. Chinensevar. rubrumaccessions are divided into 4 types according to the RAPD analysis. The first type is Zihong (No. 5), with purple梤ed and lozenge leaves. The second one is No. 12, with small, purple梤ed and egg梤ound leaves.The third type Zihei(No.1l),with black梡urple leaves. And the fourth is Hongzhe with red梠chre leaves. 5. The genes of L. Ghinense var. rubrwu comes from genes of different ecotype of L. Chinense 6. The routine of relationship and evolution among different types of L.Chinense var. rubrum is: the third type (No. 11) 梸the fourth type (Hongzhe) 棏~the second type (No. 12) 棏~the first type (No.5). 7. L.Chinense var. rubrum originated in Liuyang ,Hunan province, P. R. China. 8. With the leafcolour fro...