Study On Relationship Of Diospyros Kaki And Its Related Species And Genetic Diversity Of D. Kaki

Persimmon(Diospyros kaki Thunb.) belongs to Ebenaceae, is generally seen as fruit plants. It is generally 2n=6x=90, with exceptions of nonaploid cultivar(2n=9x=135). China, as one of the distribution and origin center of Diospyros spp., has various germplasm resources of Diospyros spp., which provide enough materials to study the origin and evolution, interspecific relationship and genetic diversity, but phylogenic relationship of Diospyros spp. has little research. The relationship between Diospyros kaki and its related species had already been widely studied, the results, however, were incomplete conform, the relationship between D. kaki and its related species was not very clear. In order to analyze the phylogenic relationship of Diospyros spp., the chloroplast DNA(cpDNA) trnQ-rps16 regions of 17 species of Diospyros spp. were sequenced. Then cpDNA polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP), ndhA and internal transcribed spacer(ITS) sequence were used to study the relationship of D. kaki and its related species. In addition, We found the genetic differences of 93 persimmon cultivars based on the variable sites among different cultivars. Mean results as follows:1. 17 species(19 genotypes) of Diospyros spp. were used to study the phylogenetic relationship by rps16-trnQ sequences, calculating substitution model of the sequence using jModel Test 2.1.5 software, than building two phylogenetic trees constructed by MP and ML methods based on model parameters. The results showed as following: materials were divided into two categories, one was for D. kaki and its related eight species, another was for the rest eight species. In the first clade, we found D. ferrea and Jinghuashi were distanted with other related species, Yunnan-yemaoshi, D. oleifera, D. lotus, D. glaucifolia, D. virginiana and Jinzaoshi were selected to be used for the following study as related species of D. kaki, and D. cathayensis were selected as an outgroup species.2. Five special primer pairs of chloroplast genome were used to amplified chloroplast DNA(cpDNA) regions of 8 Diospyros spp. species including 32 genotypes. The PCR products were digested by seven restriction enzymes. The results showed high interspecific cpDNA variations within the genus Diospyros. Twenty-two D. kaki genotypes were detected no visually variation in this study, but the bands of ndhA/MboI from different persimmon cultivars had slightly difference, which deserved to conduct further research. In addition, we could analyze the genetic differences among 93 cultivars on the basis of nrDNA ITS sequence.3. 8 species(102 genotypes) of Diospyros spp. were used to study the interspecific relationship and intaspecific genetic diversity by ndhA and ITS sequences, calculating substitution model of two sequence and their combination, than building three phylogenetic trees constructed by ML method based model parameters. The results showed as followings:(1) D. kaki was closely related to D. oleifera and Yunnan-yemaoshi, but distanted from D. virginiana. and D. cathayensis.(2) The length of all D. kaki cultivar ITS sequence was 730, including eight variation sites. 93 D. kaki cultivars was classified into 16 types based on the eight variation sites, but the sequence of ndhA had no variation sites in the 93 cultivars. The results suggested that ndhA and ITS sequence variation analysis can explained the relationship between D. kaki. and its related species, and genetic diversity were analyzed according to the eight variation sites.