Collection Evaluation And Analysis Of Hainan Lichee Germplasm Resources

Litchi (Litchi chinensis Sonn., Sapindaceae), a tropical and subtropical fruit originated from China, has become one of the most important fruit crops in china and developed rapidly in Guangdong, Guangxi Fujian and Hainan provinces from1990. China is the main country of litchi production, which area and yield are both the first in the world. In this study, investigation, collection、evaluation、genetic diversity analysis、fingerprint construction and functional composition analysis of Hainan Litchi germplasm resources was carried out. The main results were as follows:1. The growth and distribution status of wild, semi-wild litchi in Hainan was cleared and distribution map was drawed based on wild, semi-wild litchi survey. More than120copies of Litchi germplasm resources were collected and a series of norms, rules and standards were made.2. The descriptors-standard、data quality control of descriptors and the standar of data for Litchi were made.30of excellent germplasms were selected on the basis of evaluation, classification of litchi germplasm resources according to the norms.3. ISSR and AFLP molecular marker technique were used respectively for genetic diversity analysis of96and60litchi germplasm resources.180polymorphism bands were obtained using13ISSR primers. The average number of band was13.8per primer and the polymorphic ratio was90.56%.1218straps were amplified using3pairs of AFLP primers and1125straps were polymorphic(92.36%). Genetic similarity coefficients of ISSR and AFLP were0.478～0.874and0.616～0.846, respectively. Results from ISSR and AFLP markers showed that wild litchi germplasm resources covered all the groups, semi-wild germplasm resources had a few groups while cultivated germplasm almost belonged to the same group. The clustering results of the two molecular markers showed high consistency.4. According to the results of genetic similarity coefficient, the genetic basis of Hainan litchi germplasm was relatively wide while the majority of the litchi had closely phylogenetic relationships and the genetic differences was relatively narrow. The similarity coefficient showed partial normal distribution and wide genetic differences mainly existed in wild type. Cultivar litchi (semi-wild) was obviously different from wild litchi. Moreover, the wild litchi from the same forest had closely genetic relationships and strong eco-regional characteristics. Wild litchi from Bawangling was divided into different groups, indicating that genetic diversity of wild litchi from Bawangling is abundant than other forest and Bawangling is the core area of wild litchi.5. SSR finger printing of litchi germplasm was constructed using SSR and AFLP molecular marker technology.11germplasm resources could be fully separated by the two markers methods and each tested material had the only bar code. These results might provide useful reliable DNA molecular evidence for identification of species, registration of new varieties, and protection of cultivar.6. Total phenols, flavonoids and polysaccharides were extracted from litchi leaves, peel and stone by using the response surface method to optimize the ultrasonic aided technology. Three types of substance’s extraction condition and extraction process is analyzed and established a mathematical model which provide theoretical reference and basis for total phenolics, flavonoids and polysaccharide extraction of Litchi. Compared to traditional methods, the new method could significantly increased extraction rate.7. Phenols contents in pericarp and stones were analyzed from Ziniangxi, Dingxiang and Nandaowuhe litchi. Six types of phenolic compounds i.e procyanidine A1and A2, phloridzin, tamarixetin-3-rutinoside, catechin and rutin, were detected in stones. All of them are flavonoids except phloridzin. Polysaccharide in litchi leaves precipitated by40%alcohol included arabinose, rhamnose, galactose and glucose, while polysaccharide precipitated by80%alcohol did not contain glucose. DPPH radical scavenging activities of phenols and polysaccharides were evaluated. Higher DPPH radical scavenging activities of phenols were detected in litchi leaves. The DPPH radical scavenging activities of polysaccharides were significantly different in various species. Activities of polysaccharides in pericarp was higher than that of in stone and leaves of Ziniangxi, and the highest polysaccharides DPPH radical scavenging activities was observed in leaves of Dingxiang.