Study On The Bacterial Diversity And Change Rule Of Haliotis Diversicolor Reeve’s Nursery Ecosystem

Haliotis diversicolor Reeve is the main breeding species in the South coastal area of China.In recent years, because of the enlargement of farming scale, degeneration of genetic characterization, deterioration of breeding ecological environment and the lagging of studies on abalone disease, the disease of abalone seedling occured frequently. It was confirmed that the bacteria is one of the main pathogens. QPCR and PCR-DGGE technology were used in the research to study the community diversity and variety law of bacterrial in ecological environment of Haliotis diversicolor Reeve; it includes planktonic bacteria in aquatic water, bacteria in phycoshere on the attached substances and bacteria inside of the abalone. The aim of the study is to provide a reference for abalone scientific breeding and health culture, and to procide scientific evidence for the relationship between environmental changes and bacterial diseases of abalone seedling stage.The methods of total DNA extraction of bacterial from Haliotis diversicolor Reeve was compared, total DNA of the bacteria inside of animal was obtained by the optimization of the extraction method. The community diversity and variety law of bacteria of ecological environmment of Haliotis diversicolor Reeve breeding were studied by QPCR and PCR-DGGE, the result showed that:bacterial community diversity of phycosphere was affected by adding algae growth hormone and the feeding of a large quantity algae by abalone larvae. The planktonic bacteria of nursery water had an obvious change, because the planktonic bacteria were susceptible physical and chemical factors of water and the mode of larval rearing. The colony of bacteria inside of abalone was mainly composed by the bacteria of gills and digestive tract. The variation law of the bacteria was sffected by the growth and development of the host and bacterial flora inside the body. the diversity of bacteriawas lower along with small munber of bacteria in planktonic bacterial; The creeping period, the munber and diversity of bacteria increased, and the diversity maintained stable to a certain level; the number of bacteria continued to increase, but less diverse in the later stage of nursery, the bacteria diversity increased after the larvae stripped from the attached substances.