Morphological And Genetic Diversity Among Different Species And Populations Of Abalone

Abalone is an important aquaculture shellfish in China with high nutritive value and prominent economic value.However,as a result of the human factors such as long-term artificial breeding,the abalone germplasm resource become vestigial and the economic trait declined,so it is necessary to strengthen the protection of germplase resources.In this study,morphological and genetic diversity of common aquaculture abalone species were studied using morphological markers and DNA molecular markers.The main research contents are as follows:The morphological differences of five abalone species,including Haliotis fulgens,Haliotis rufescens,Haliotis discus hannai,Haliotis divericolor and Haliotis gigantes,were quantitatively studied by landmark method,elliptic Fourier analysis and linear measurement.The linear measurement method was used to study the morphological differences of the seven geographical populations of H.discus hannai,which is the main cultured species in Fujian Province,and the multiple regression equations of quality traits such as total weight,soft body weight and fatness were obtained.Based on 21 pairs of microsatellite primers,we investigated the genetic diversity of 7 geographical populations of H.discus hannai.The result showed that genetic diversity of the 7 populations is relatively high,but there are more loci in the Qingdao,Dalian,and South Korea groups that are extremely deviated from the balance of Hardy-Weinberg.Meanwhile the genetic differentiation of Yangxia and other populations were found.The dendrogram based on morphological distance and genetic distances showed that the morphological differences between the same species may be more affected by the environment.Based on whole genome sequencing,the population-specific SNP markers in South Korea,North Japan,South Japan,South China and Northern China were screened,and the characteristics of these 102 SNP markers were analyzed.The linear measurement method was used to study the morphological differences between the H.discus hannai and the reciprocal crosses with Haliotis fulgens and the backcross progeny.The results showed that there were significant differences in the morphological differences between the four populations.The genetic diversity between the parents(HD,HF)and their reciprocal progeny and backcross progeny were studied using 24 pairs of microsatellite primers.There was obvious genetic differentiation among the five populations.The genetic diversity of H.fulgens was significantly lower than the other four groups,and the genetic diversity of the other four groups was relatively high,but most of the three hybrid-progeny were extremely deviated from the Hardy Weinberg equilibrium,probably because the hybrid generation received the greater artificial interference.The dendrogram constructed by morphology and genetic distance found that the shell shape of these five populations is likely to be affected by maternal inheritance.Using whole genome sequencing and SNP genotyping,the genome-wide association analysis was performed on morphological traits of 222 half-sib pedigrees abalone.After quality control,a total of 1431014 SNPs were used for whole-genome associated analysis,and 159 SNP markers were significantly associated with 8 morphological traits.The genes related to shell shape and biomineralization processs such as CUBN,EGF-like,FGFR,CALM and PLC were found by annotation,which provided a new reference for subsequent research.