Comparative Analysis Of Genetic Diversity Between Yunnan Gray Goose And Other Six Domestic Goose Populations

Yunnan gray goose is mainly produced in Tonghai County,Yuxi City.Its meat is delicious and suitable for pickling cured geese,which is highly favored by local residents and foreign consumers.In recent years,there have been detailed descriptions of the regional distribution,production performance,and appearance characteristics of Yunnan gray geese,but there is still a lack of systematic research on the population genetic background and genetic relationships with other goose species of Yunnan gray geese.Therefore,this study used Mitochondrial DNA matrilineal Genetic marker and micro Satellite DNA parental Genetic marker to detect and compare the population variation of Yunnan grey goose and Yunnan white goose,Sichuan white goose,Wanxi white goose,Yangzhou white goose,Lander goose and Rhine goose,and clarified the genetic diversity difference between Yunnan grey geese and other geese populations,population genetic relationship and genetic differentiation,and the Introgression of other geese to Yunnan grey geese.The results are as follows:(1)The total length of the mt DNA D-loop region sequence obtained in this study is1126 bp.The A,T,C,and G base content of the Yunnan gray geese are 25.4%,31.1%,28.6%,and 14.9%,respectively,which are basically consistent with the base proportion of other domestic geese populations.A total of 2 mutation sites were detected in 7 domestic goose populations,while only 1 mutation site was detected in Yunnan gray geese,indicating a single maternal origin of Yunnan gray geese.Based on the mt DNA D-Loop region sequence of domestic geese,a phylogenetic tree was constructed.The results showed that Lander geese,Rhine geese,and Yili geese were clustered into a large group of Anser anser,while Yunnan gray geese,Yunnan white geese,Sichuan white geese,Wanxi white geese,Yangzhou white geese,and A cygnoides were clustered into a large group,indicating that Yunnan gray geese originated from A cygnoides and confirming two theories of origin of domestic geese: Chinese domestic geese(except for Yili goose)originated from A cygnoides,while Yili goose and Western domestic geese originated from A anser.(2)Analysis of microsatellite DNA parental markers showed that 188 alleles were detected at 14 microsatellite loci in 7 domestic geese populations,and the number of alleles at each gene locus in 7 domestic goose populations ranged from 5 to 27.The average number of alleles at 14 gene loci in Yunnan gray geese is 5.214±0.793,and the average effective allele number is 3.059±0.379.Yunnan gray geese have 2 and 1 unique allele at CKW12 and MCW14 loci.Respectively,the average apparent heterozygosity of Yunnan grey geese is 0.494±0.060,the average expected heterozygosity is 0.592±0.056,and the population Coefficient of inbreeding is 0.133±0.080,indicating that there is inbreeding in Yunnan grey geese.The polymorphism information content of Yunnan gray geese is 0.539,belonging to a high degree of polymorphism(PIC>0.5).The genetic differentiation degree of Yunnan grey geese and Sichuan white geese is the smallest,with an Fst value of 0.017 and an Nm value of 14.545;The degree of genetic differentiation with Lander geese is the highest,with an Fst value of 0.162 and an Nm value of 1.296.The seven domestic geese populations can be divided into two major groups according to the Genetic distance clustering,namely,the Chinese domestic geese and the European domestic geese.Under the Chinese domestic geese category,Yunnan gray geese and Yunnan white geese and Sichuan white geese in Southwest China gather into one branch,while Wanxi white geese and Yangzhou white geese in East China gather into another branch.The structure program was used to analyze the data of seven domestic geese populations.The results showed that there was a certain degree of Introgression in Yunnan grey goose.When K=2,Yunnan grey geese and other domestic geese in China were divided into one group,and European domestic geese were divided into one group.When K=3,Chinese domestic geese can be further divided into two categories,one is Yunnan white geese,Yunnan grey geese and Sichuan white geese in southwest China,and the other is Wanxi white geese and Yangzhou white geese in East China.Among them,4.2% of Yunnan grey geese have blood infiltration in Europe,and 26.4% of East China geese have blood infiltration,which is consistent with the results of Broussonetia papyrifera with Genetic distance.Compared with other domestic geese,the Introgression of Yunnan grey geese is the largest.In this study,two different genetic marker were used to reveal the rich genetic diversity of Yunnan grey goose from the perspective of matrilineal inheritance and parental inheritance,which,like other Chinese domestic goose,evolved from the wild goose.There is a certain degree of genetic differentiation between Yunnan grey goose and Yunnan white goose,indicating that Yunnan grey goose can used as an independent breed resource.Compared with other domestic goose in China,the western introgression of Yunnan grey goose is greater.Provide theoretical basis for formulating conservation and breeding plans for Yunnan gray goose in the future.