Diversity Analysis Of Apis Cerana In Sichuan Based On Morphological And SLAF-seq Techniques

The area of Sichuan Province is very wide,the terrain and climate are very complex and diverse,and the species of nectar plants is rich,which resulted in the rich honeybee germplasm resources.In this study,129 colonies of Apis cerana in 43 districts and counties in Sichuan area are systematically investigated by two methods:morphological characteristic markers and DNA markers based on the SLAF-seq technique.The analyses in this study could provides an important basis for the identification,protection and beekeeping application of the germplasm resources of the Apis cerana honeybees in Sichuan.The main results are as follows:1.Analysis of morphological characteristics diversityIn the analysis of 19 morphological indexes of Apis cerana in Sichuan,there were significant differences(P<0.01)among the samples,and 19 morphological indexes correlation analysis found that the elbow pulse index,tibial length,femur length,tarsus width and length of wax mirror were not correlated with other indexes(P>0.05),other morphological indexes were significantly related with each other(P<0.05).the result of direct cluster analysis of morphological indexes is consistent with that of the principal component cluster analysis.The results indicated that the distribution of the Apis cerana in Sichuan areas obviously divided into 3 major clusters,the honeybees in Aba region,the honeybees in Ganzi region,and the honeybees in other regions.The result of discriminant analysis was consistent with that of cluster analysis.The distribution of the Apis cerana types in Aba region is more concentrated and separate far away from the other regions,and they were significantly differed from that of Ganzi region,and the samples from some regions gathered together then apart from other parts of Sichuan Province,Sichuan and Liangshan(Panzhihua)states.The results showed that geographical environment had an strong influence on the morphological differentiation of Chinese bees in Sichuan areas.2.DNA diversity analysisIn this study,38 samples of honeybees in Sichuan province were used as the mainresearch objects.74 megabyte reading length data were obtained by SLAF-seq sequencing technique.The experiment obtained 268631 SLAF tags were explored,the average sequencing depth of the label was 253.24 x.189234 polymorphic SLAF tags were detected,and a total of 1018013 SNP tags were obtained.The population genetics analysis showed that the Apis cerana honeybees in the Sichuan area were obviously divided into six groups: Aba population,No.1 Ganzi population,No.2 Ganzi population,the Sichuan basin population,Hejiang population and Liangshan-Panzhihua population.There were significant differences between the polymorphic SNP loci in Ganzi population and the others.The Apis cerana honeybees in Ganzi has a possibility of differentiation.A protected zone has been established for the Apis cerana honeybees in Aba,and the gene exchange between this bees and other regions' bees was dropped,and its primitive genetic diversity was conserved.