A Study Of Genetic Purity Inference Of Green Peafowl And An Analysis Of Genetic Diversity Of Captive Population

The global population of green peafowl(Pavo muticus)have a sharp declined in the 20th century,due to the hunting,anthropogenic disturbance and habitat degradation.The protection of P.muticus need to combine In situ conservation with Ex situ conservation,as well as reintroduction.Captive breeding for reintroduction is potentially an important measure for localized population restoration.But green peafowl can hybridize with blue peafowl(P.cristatus)and produce fertile offspring that can backcross with ancestral species.Hybrids backcrossed to green peafowl for a few generations are indistinguishable from pure green peafowl in appearance.So in order to avoid anthropogenic genetic contamination,discriminating hybrids and breeding pure green peafowl are the main emphasis of the study in Ex situ conservation.In this study,we developed technology to identify hybrids using mitochondrial COI and Cyt b gene sequences,and 16 microsatellites.Meanwhile,we also use these markers to study the genetic diversity of P.muticus,so that it could provide some advices for population management in the future.The main results were as follows:1.Using COI and Cyt b gene sequences based on K2P pairwise genetic distance to construct NJ tree could exclude individuals of the blue peafowl maternal line.What's more,the result showed the Cyt b fragment was better choice for a marker to separate green from blue peafowl than COI gene and the combination of COI and Cyt b genes.2.Nuclear genetic component analysis based on 16 microsatellites was performed using STRUCTURE(assuming K=2)and NewHybrids analysis.The result showed it could correctly discriminate pure green and blue peafowl through using reference pure green(N=18),blue(N=21)peafowls and known hybrids(N=12)to set up a criteria by calculating the probability that an individual is either pure green or pure blue peafowl at 95%confidence.This method was applied to identify 59 peafowl of ambiguous genetic composition and 33 pure green peafowls were eventually discriminated.However,because of the limit of the numbers of the microsatellites,further research in identifying hybrids of belonging to the different hybrid categories(F1,F2 hybrids and backcrosses to ancestral species)was lack of reliability.3.The analysis of genetic diversity indicated that whole P.muticus population has a low genetic diversity.The heterozygosity and polymorphism information content showed that the genetic diversity of peafowls from LG was more abundant than QG group.Both groups showed a significant absence of heterozygote and high similarities in genetic background of group individuals.It suggested inbreeding at the different degree might existed in two groups and the degree of inbreeding in LG group was higher than QG.According to this situation,we recommend both populations need carry out genetic management and individuals with a greater genetic distance should be paired preferentially.Besides,both of them should carry out effective communication as early as possible,if possible.