Establishment Of Tetranychus Urticae Family And Genetic Analysis Of Five Main Families

Odontobutis potamophila belongs to Odontobutis genus,it is an important species in the fishery resources widely distributed in river systems of Southeastern China,which including in the middle reaches and the lower reaches of Yangtze River,Qiantang River and Minjiang River systems.The fish is a small carnivorous fish living in benthic freshwater,their meat is delicate, taste delicious and is rich in nutrition,so deeply loved by the most of people, have a good development prospect in the market. In recent years,with the rapid decline of the wild fish resources and the growing market demand,O.potamophila has become a very promising aquaculture varieties. At present the country has been scattered polyculture and set of support in the O.potamophila.but production is still far from satisfying consumer demand market.In the production process of the fish, production units do not pay attention to the fish germplasm resource management, cause the occurrence of farmed fish slower growth, increased diseaseand other germplasm degradation phenomenon.Seed has become one of the main "bottleneck" in constraint O.potamophila stable development of aquaculture.Therefore the urgent need to improve the existing status quo of germplasm,bred a high yield, fast growth, high disease resistance varieties.In the present study, Morphological measurements of morphological parameters to O.potamophila between four geographic population were analyzed, concluded themorphological differences between different groups and relationships.and then let the four geographical population groups of O.potamophila be basic groups, establish several combination and family, every family and the growth traits were determined, choose the best combination of parental and family, as the basic groups for further genetic selection. Finally use microsatellite primers to detected thegenetic structure of O.potamophila excellent family, explore the genetic diversity between each family.These can provide a basis data for the O.potamophila breeding. The results were shown as follows:1.Analysis of morphological variations among four different geographic populations of O.potamophilaThree kinds of multivariate analysis methods including cluster analysis, principal component analysis and discriminant analysis were used to comparative analysis fifteen proportional parameters of morphological characters in four different geographic populations of O.potamophila(JD, DT, SY and DXS).The results of cluster analysis showed that morphological characters were similar between SY and DXS,but quite different from that of DT and JD.Principal component analysis to construct the five principal components, the contribution rate of total variance between the different groups were 18.070%,16.717%,11.374%,9.504% and 7.182%, respectively. And the cumulative contribution rate was 62.847%. The results of principal component analysis showed that there were some morphological differences among the four different geographic populations in body length, head length, eye back length, body height and body thickness. Discriminant functions of four populations were established with eight different variables.The discriminant accuracy was 62.0%-100.0% for PI and 62.0%-98.0% for P2, the integrative discriminant accuracy was 77.0%. The results showed that four O.potamophila in the form of both groups have a certain degree of similarity differences.2.The comparison of growth performances of different families in O.potamophilaAccording to the nest design,four geographical population groups of O.potamophila were collected to construct full-sib families among stocks as well as within stocks.Comparison of the growing performance among 34 full-sib families constructed was analyzed byanalysis of variance and multiple comparisons.The results demonstrated that the differences among growth performances of the progeny of different families were extremely significant.In the whole growth process of measurement,F36,F35,F29,F16 and F1 families has a better performance of the growth rate and growth in full length or weight.showed significant growth advantage.It was considered that F36,F35,F29,F16 and F1 families were of excellent family,and could be used as the basis populations for further genetic selection.Through the correlation analysis on the source of parents and offspring growth performance, high growth performance of O.potamophila The majority of male parent source of Zhejiang Jiande group and female parent source of Anhui Dangtu group, indicated that Zhejiang Jiande group were suitable to be male parents and Anhui Dangtu group were suitable to be female parents.3.Studies on genetic diversity of five O.potamophila families as revealed by microsatellite markersMicrosatellite markers were used to analyze the genetic diversity of 152 individuals from five O.potamophila families (F1,F16,F29,F35 and F36).The results showed that a total of 147 alleles were obtained from the five families by 9 pairs of microsatellite primers.The number of allele locis ranged from 1 to 8,the average effect alleles ranged from 1.00 to 4.78, The average observed heterozygosity values were 0.6520,0.6658,0.5440,0.4817 and 0.6137,respectively. The average expected heterozygosity values were 0.5839,0.5227,0.5547,0.3851 and 0.4079, respectively.Five families were moderately or highly polymorphic,All of these five families were middle polymorphism, and the ascending order the PIC was F1,F29,F16,F36 and F35,respectively. The coefficient of strain differentiaton among the families was 0.1717, and there was certain genetic differentiation existed among the five families. Phylogenetic relationship of the five families was analyzed by using UPGMA methods based on their genetic distances and the results showed that the F1 and F29 shared the nearest relationship and clustered in the first group, the F35 and F36 in the second group,while the Fl was in a separate group.