Survival Investigation Of Wild Litchi Population Grown In Bobai County And Genetic Diversity Analysis Of Part Litchi Resources From Wild, Semi-wild And Culture In Guangxi Province Of China

The purpose of the present research was to provide basic data for protection and utilization of litchi resources (Litchi chinensis sonn.) grown in Guangxi province. Three genotypes of litchi resourcres distributed in Gunagxi province were collected from wild, semi-wild and cultivation, respectively. The age structures of wildlife population grown in Bobai county and the morphological traits of the fruits of semi-wildlife and cultivated populations were observed. Whereafter, the heredity evolution of tested three genotypes of litchi resources was analyzed with simple sequence repeat (SSR) method. At last, the survival situation of wildlife litchi, the genetic diversity, and the genetic relationship among the three litchi resources in Guangxi province were assessed. The main results from our experiments were as follows:1. The survival curve of wildlife litchi population, which was grown in Bobai county of Guangxi province, was belonged to Deevey-I type by age structure analysis. The survival rate of wildlife population was monotonous decreased, and the accumulated death rate was monotonous increased concomitantly, in which the altered degree was more obvious in early stage than that of in later stage. There were twice death crest-times during the whole growth period. Aboved results suggested that the current survival situation of wildlife litchi population in Guangxi province is quite serious, and the protective measure for stabilizing the wildlife litchi population should be carried out urgently.2. The morphological variations measurement and variance analysis demonstrated that there were a significant deviation in the weight, size, pulp thickness, and eatable rate between the fruits from three genotypes of litchi populations. According to the shape of crack lobes in mature fruits, the crack lobes of the three genotypes of litchi populations were divided into cuspidal, protrude and flat three types, in which the percentage of protrude type was prevalent.3. 10 pairs of SSR primers were used for analyzing 32 accessions of wildlife litchi, 46 accessions of semi-wild litchi, and 9 accessions of cultivated litchi. The genetic diversity of semi-wild litchi population was larger than that of wild litchi based on the results of genetic diversity analysis. The 32 portions of analyzed wildlife litchis harvested by us could be divided into 5 groups, 46 portions of semi-wild litchi into 7 groups, and 9 portions of cultivars into 6 groups respectively at 0.65 similar levels, according to unweighted pair-grouped average program (UPGAM) dendrogram. The genetic similarity coefficient and genetic distance assessment suggested that the largest genetic distance among the three genotypes of litchi was between cultivated litchi and wildlife litchi. However, the semi-wild litchi was similar to wildlife litchi in genetic material.