Genetic Diversity Of Geographic Populations Of Seabuckthorn Carpenter Moth: Holcocerus Hippophaecolus (Lepidoptera: Cossidae)

Seabuckthorn, Hippophae rhamnoides L. is a kind of shrub or small arbor, which belongs to the category of Hippophae and the family of Elaeagnaceae. It has strong adaptability to relative atrocious eco-environment,which is pioneer tree for desertification prevention, soil and water conservation in the"Three Norths Areas"(Northern, North-East and North-West) of China. Seabuckthorn has abundant bio-active substances, which makes it an imorptant source plan for both medical and food use such as medicine, health protection and cosmetics etc. There are 2 million hm2 of seabuckthorn forest in China, composed above 90%of seabuckthorn forest in the world, which plays important roles in improving eco-environment and promoting socio-economic development in poverty restricted areas.Holcocerus hippophaecolus Hua, Chou, Fang et Chen belongs to the category of Holcocerus, the family of Cossidae and the item of Lepidoptera, which is an outbreak pest appeared in"Three Norths Areas"of China in decade years. It damaged seabuckthorn forests to death about 160 thousand hm2 in Shanxi, Shaanxi, Inner Mongolia, Ningxia, Liaoning and Gansu etc. The disaster became one of the main restricting factors for the development of seabuctkorn industries and influence eco-safety and social economic development in seabuckthorn distribution regions. In recent years, studies and reports of H. hippophaecolus focused on biology and zoology, species and suppression function of natural enemies, development and utilization of sexual pheromone, countermeasures both at forest management and chemical control etc. However, the study on outbreak mechanism of H. hippophaecolus has not been mentioned before. To such species with large disaster areas and natural distribution regions like H. hippophaecolus, study on genetic relationship of H. hippophaecolus population among different geographic regions by utilizing molecular biological techniques may explore the internal relationship in quantity and space of H. hippophaecolus population among different regions, which plays basic role to explore the mechanism of population outbreak, therefore provide scientific evidence for regional control of H. hippophaecolus.The study on genetic diversity of geographic population of H. hippophaecolus was carried out by using AFLP (Amplified Fragment Length Polymorphism) molecular marking technique in this thesis, the genetic biodiversity study was implemented by using six geographic populations distributed in the main disaster regions of H. hippophaecolus in China. The main results are as follows:(1) A set of adaptable technical reaction system was established through optimizing many factors affecting the AFLP analysis process of H. hippophaecolus. Firstly, the improved protein enzyme K–SDS method has been choosen by comparation of different DNA extracting methods. These genome DNA samples isolated from H. hippophaecolus with high purity and integrality are provided with high quality DNA template for further AFLP analysis. Ten primers combination with clear amplified bands, high polymorphism, which pave the way for further AFLP genome analyzing of H. hippophaecolus were selected from 80 pairs of primers combination like EcoR1+3/Mse1+3.(2) AFLP fingerprinting maps of 180 testing individuals from six geographic populations of H. hippophaecolus were established by using four pairs of further selected primers combination. Totally 284 amplified bands were obtained, with the average of 71 clear amplified bands. The most of AFLP clear amplified bands are the primer combinations of E1/M3, which are 80 bands, the least primer combinations of E2/M1 with 61 bands.(3) According to the DNA fingerprint illustrative atlas gained from the experiments,to analyze these populations through systematic clustering methods, the geographic populations of these H. hippophaecolus existing certain genetic diversity. Through the AFLP statistic results of H (Nei's genetic diversity) and I (Shannon's information index), both of them showed that the genetic biodiversity of H. hippophaecolus mainly consist in the internal population.(4) Based on the results revealed in the UPGMA (Unweighted Pair Group Method with Arithmetic average) analysis on genetic distance of H. hippophaecolus, the population could be divided into three groups according to the distance of relative relationships: Youyu of Shanxi and Fengning of Hebei Group, Wuqi of Shaanxi and Dongsheng of Inner Mongolia Group, Pengyang of Ningxia and Jianping of Liaoning Group. Namely the distance of relative relationships between the population of Youyu of Shanxi and Fengning of Hebei is close, but the clustering of the two populations is far from the clustering of Pengyang of Ningxia and Jianping of Liaoning.