Genetic Diversity Analysis Of The Grass Carp(Ctenopharyngodon Idellus) In Guangdong Province By Morphology And Microsatellite Markers

In this study,morphological?traditional and framework quantifiable traits,landmark points?and microsatellite markers are used to analyze the genetic diversity of455 fishes of 12 grass carp populations in Guangdong Province.They are including 1fingerling population?Shaoguan Shixing,L-Shixing?,3 fry populations?Heyuan Deng-ta,M-Heyuan;Zhongshan Sanjiao,M-Zhongshan;Taishan,M-Taishan?,5 culturing populations?Yingde Lianjiangkou,Y-Yingde;Heyuan Liucheng,Y-Heyuan;Zhuhai,Y-Zhuhai;Zhongshan Banfu,Y-Zhongshan;Maoming Aotou,Y-Maoming?and 3 wild populations?Beijiang,YE-Beijiang;Dongjiang,YE-Dongjiang;Xijiang,YE-Xijiang?.The results of 3 fry populations show that:1)In terms of morphology:M-Heyuan population has the longest snout length?p<0.05?,M-Zhongshan population has the highest body height?p<0.05?,and M-Taishan population has the highest caudal peduncle height?p<0.05?.The landmark points method shows that M-Zhongshan and M-Taishan are similar in shape and showing a large body with a small head,but the M-Taishan population is more slender than the M-Zhongshan population.2)In terms of microsatellite markers:The average polymorphic information content?PIC?of the 3populations is 0.823,with high genetic polymorphism?PIC>0.5?,the PIC of M-Taishan population?0.726?is lower than those of M-Zhongshan population?0.817?and M-Heyuan population?0.808?.The 3 populations show significant genetic differentiation among populations,within populations and between individuals?p<0.05?,while M-Taishan and M-Thongshan and M-Heyuan populations are at a moderate level of genetic differentiation(0.05<F_ST<0.15).From the point of view of genetic distance,cluster analysis and genetic structure,M-Heyuan and M-Zhongshan populations are relatively closer,but M-Taishan population has a certain genetic distance from them.The results of 5 culturing populations show that:1)In terms of morphology:Y-Maoming population has the largest body weight?p<0.05?,Y-Zhongshan population has the longest head length and snout length?p<0.05?,Y-Yingde population has the largest eye diameter?p<0.05?,Y-Zhuhai population has the largest interorbital distance?p<0.05?,Y-Heyuan population has the longest caudal peduncle length?p<0.05?.The landmark points method shows that the head of Y-Zhongshan population is long while those of Y-Heyuan and Y-Zhuhai populations are short.There are no obvious difference in the overall 5 populations.2)In terms of microsatellite markers:The average PIC of five populations is 0.839,with high genetic polymorphism?PIC>0.5?,among which the PIC of Y-Maoming population?0.843?is the highest and that of Y-Zhongshan population?0.800?is the lowest.The 5 populations have significant genetic differenti-ation among populations,within populations and between individuals?p<0.05?,but there is no significant genetic differentiation between Y-Heyuan and Y-Zhongshan populations?p>0.05?.The results of 3 wild populations show that:1)In terms of morphology:The YE-Dongjiang population and the YE-Xijiang population have significant differences in the8 traditional quantitative traits?p<0.05?,such as body weight,body height,and head length.The landmark points method shows that the YE-Beijiang population has a small head and a large torso,while the YE-Xijiang population is opposite.2)In terms of microsatellite markers:The average PIC of the three wild populations is 0.835,with high genetic polymorphism?PIC>0.5?.the genetic differentiation of the three populati-ons is not significant among the population?p>0.5?,but within populations and between individuals?p<0.05?.The genetic differentiation between YE-Beijiang population and YE-Xijiang population is significant?p>0.05?,but the genetic differentiation is low(F_ST<0.05).The results of 12 populations show that:1)In terms of morphology:The landmark points method shows that theY-Zhuhai population,the L-Shixing population,the Y-Yingde population,the Y-Maoming population,the M-Heyuan population and the Y-Heyuan population have a big head with a small torso,while the others are opposite.2)In terms of microsatellite markers:The average PIC of the 12 populations is 0.839,with high genetic polymorphism?PIC>0.5?,among which the PIC of Y-Maoming population?0.843?is the highest and that of Y-Taishan population?0.726?is the lowest.The 5populations have significant genetic differentiation among populations,within populations and between individuals?p<0.05?,However,the YE-Dongjiang population has significant genetic differentiation with only 3 of them?L-Shixing population,M-Heyuan population and M-Taishan population??p<0.05?.From the point of view of genetic distance,cluster analysis and genetic structure,the 11 populations are relatively closer,but M-Taishan population has a certain genetic distance from them.In summary,the overall shape of grass carp populations in Guangdong has a little difference,genetic polymorphism of them is high,but genetic distance and genetic differentiation of them is small,genetic structure of them is similar.