Amphioctopus fangsiao(Cephalopoda:Octopodidae)is an important commercial species in the coastal waters of China.In recent years,however,the resource of A.fangsiao have declined because of habitat destruction and overf...Amphioctopus fangsiao(Cephalopoda:Octopodidae)is an important commercial species in the coastal waters of China.In recent years,however,the resource of A.fangsiao have declined because of habitat destruction and overfishing.To analyze the genetic variations of A.fangsiao caused by the fluctuation of resources,the population genetic structure of nine sampling locations collected from the Bohai Sea to the South China Sea were investigated,using mtDNA COI fragments and microsatellite DNA.The results of F-statistics,AMOVA,STRUCTURE and PCA analyses showed three phylogeographic clades(Clades A,B and C),revealing limited genetic exchange between north and south populations.These clades diverged in 2.23(Clades A and B)and 3.67(Clades A,B and C)million years ago,during the dramatic environmental fluctuations,such as sea level and temperature changes,have exerted great influence on the survival distribution pattern of global organisms.Our results for low genetic connectivity among A.fangsiao populations provide insights into the development of management strategies,that is,to manage this species as separate management unit.展开更多
To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The ...To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity （GS） values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions （0.447）, while Australia accessions have the furthest distance （0.503）. A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.展开更多
To estimate the genetic diversity of the only captive Saiga antelope(Saiga tatarica) population in China,40 umbilical cord samples were collected and mitochondrial(control region) and nuclear(microsatellite) variabili...To estimate the genetic diversity of the only captive Saiga antelope(Saiga tatarica) population in China,40 umbilical cord samples were collected and mitochondrial(control region) and nuclear(microsatellite) variabilities were assessed.Both of the markers revealed low genetic variability(or high genetic homogeneity) within the population.The microsatellites yielded monitoring ranges of 2-6 alleles.The observed heterozygosities ranged from 0.28 to 0.83,and the expected heterozygosities were between 0.27 and 0.71.The Shannon information index(Shannon I) and Polymorphic Information Content(PIC) presented overall means of 0.87 and 0.43,respectively.The gene diversity was 0.49.We found only two haplotypes in the population,and the haplotype and nucleotide diversities were 39.1% and 1.13%,respectively.Founder events,bottlenecks and inbreeding have contributed to the low genetic variation observed in this population.Our findings revealed the extent of genetic diversity maintained in the present population and the urgency of implementing a protection plan,introducing animals from other populations to enhance saiga's genetic variation.展开更多
Seventeen microsatellite loci were used to assess the genetic variation and population structure of six endangered duck populations in China. PIC, heterozygosity with two estimators of genetic differentiation （FST an...Seventeen microsatellite loci were used to assess the genetic variation and population structure of six endangered duck populations in China. PIC, heterozygosity with two estimators of genetic differentiation （FST and GST）, and Nei＇s standard genetic distance were evaluated. The results showed that these six endangered duck populations showed high polymorphism. The propor- tion of inter-population subdivision among the six duck populations ranged between 17.0 and 14.7%. The average heterozygosity was 0.706, 0.702, 0.691, 0.676, 0.604, and 0.660 in the Gaoyou, Liancheng, Jinding, Beijing, Shaoxing, and Jianchang ducks, respectively. The average PIC ranged from 0.561 to 0.663. Finally, the results showed higher genetic diversity and difference above the levels of genetic variation among all the populations.展开更多
基金The National Natural Science Foundation of China under contract Nos 32170536 and 31672257。
文摘Amphioctopus fangsiao(Cephalopoda:Octopodidae)is an important commercial species in the coastal waters of China.In recent years,however,the resource of A.fangsiao have declined because of habitat destruction and overfishing.To analyze the genetic variations of A.fangsiao caused by the fluctuation of resources,the population genetic structure of nine sampling locations collected from the Bohai Sea to the South China Sea were investigated,using mtDNA COI fragments and microsatellite DNA.The results of F-statistics,AMOVA,STRUCTURE and PCA analyses showed three phylogeographic clades(Clades A,B and C),revealing limited genetic exchange between north and south populations.These clades diverged in 2.23(Clades A and B)and 3.67(Clades A,B and C)million years ago,during the dramatic environmental fluctuations,such as sea level and temperature changes,have exerted great influence on the survival distribution pattern of global organisms.Our results for low genetic connectivity among A.fangsiao populations provide insights into the development of management strategies,that is,to manage this species as separate management unit.
基金supported by the National Natural Science Foundation of China (30800700)the China Agriculture Research System
文摘To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity （GS） values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions （0.447）, while Australia accessions have the furthest distance （0.503）. A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.
基金supported by a special grant from the State Forestry Administration of China (201004054)
文摘To estimate the genetic diversity of the only captive Saiga antelope(Saiga tatarica) population in China,40 umbilical cord samples were collected and mitochondrial(control region) and nuclear(microsatellite) variabilities were assessed.Both of the markers revealed low genetic variability(or high genetic homogeneity) within the population.The microsatellites yielded monitoring ranges of 2-6 alleles.The observed heterozygosities ranged from 0.28 to 0.83,and the expected heterozygosities were between 0.27 and 0.71.The Shannon information index(Shannon I) and Polymorphic Information Content(PIC) presented overall means of 0.87 and 0.43,respectively.The gene diversity was 0.49.We found only two haplotypes in the population,and the haplotype and nucleotide diversities were 39.1% and 1.13%,respectively.Founder events,bottlenecks and inbreeding have contributed to the low genetic variation observed in this population.Our findings revealed the extent of genetic diversity maintained in the present population and the urgency of implementing a protection plan,introducing animals from other populations to enhance saiga's genetic variation.
基金This work was supported by the National High-tech Research and Development Program (863 Program) (No. 2001AA243082)the National Natural Science Foundation of China (No. 30170673).
文摘Seventeen microsatellite loci were used to assess the genetic variation and population structure of six endangered duck populations in China. PIC, heterozygosity with two estimators of genetic differentiation （FST and GST）, and Nei＇s standard genetic distance were evaluated. The results showed that these six endangered duck populations showed high polymorphism. The propor- tion of inter-population subdivision among the six duck populations ranged between 17.0 and 14.7%. The average heterozygosity was 0.706, 0.702, 0.691, 0.676, 0.604, and 0.660 in the Gaoyou, Liancheng, Jinding, Beijing, Shaoxing, and Jianchang ducks, respectively. The average PIC ranged from 0.561 to 0.663. Finally, the results showed higher genetic diversity and difference above the levels of genetic variation among all the populations.
