| Apis cerana in central China is a branch of the Chinese honeybee(Apis cerana cerana),which is a unique honeybee germplasm resource and an important pollinating insect in China’s agricultural production,with significant social and ecological benefits.The Shennongjia Forest Area is the only national livestock and poultry genetic resources reserve for Apis cerana in central China,with an altitude difference of 2700 m.The genetic differentiation of Apis cerana in central China germplasm resources under different altitudes and climatic conditions is unknown,which may lead to disorderly introductions and disease prevalence,limiting the scientific conservation and utilization of Apis cerana in central China germplasm resources.In this study,a total of 175 worker bee colonies(2625 individuals in total)from six different altitudes(0 m-500 m,500 m-1000 m,1000 m-1500 m,1500m-2000 m,2000 m-2500 m,2500 m-3000 m)in Shennongjia were subjected to morphological indexes and whole genome resequencing,with the aim of studying on the diversity and differentiation of genetic resources of Apis cerana in central China in Shennongjia,analyze their ability to adapt to climate change,and provide a scientific basis for guiding the rational use of germplasm resources of Apis cerana in central China in Shennongjia in areas with very different climates in forest areas,The main results are as follows:1.Study on the morphological diversity of Apis cerana in central China in Shennongjia and its relationship with climate and environmental changesThe results of One-way ANOVA showed that 26 of the 33 morphological indicators of Apis cerana in central China population at different altitudes in Shennongjia were significantly different(P<0.05),and 11 of these characteristics(FL,FB,S3,WL,WT,L6,T6,T3,T4,Fe,ML)had significant correlation coefficients with altitude(P<0.05).The results of discriminant analysis,cluster analysis and principal component analysis consistently showed that bee colonies at 0 m-500 m,2000 m-3000 m and 2000 m-3000 m altitudes could be distinguished into three categories.Bee colonies from 0 m-500 m,1000 m-1500 m and 2500 m-3000 m above sea level were selected as representatives for coloration observation,the results showed that the body color of Apis cerana in central China became darker as the altitude increased,and altitude was the main factor driving the morphological differentiation of Apis cerana in central China.2.Genetic diversity of Apis cerana in central China in Shennongjia and its guiding value for scientific utilization of germplasm resourcesGenetic diversity of Apis cerana in central China from six different elevation regions in Shennongjia is rich,but no genetic differentiation has occurred in the genome.The results of principal components,population genetic structure and phylogenetic tree analysis showed that the BBY apiary in the 2500 m-3000 m altitude group and the DLT apiary in the 2000 m-2500 m altitude group are pure-bred Apis cerana in central China colonies with no gene exchange.Colonies in the altitude range of 1000 m-2000 m are highly heterogeneous,and colonies are not easily distinguished.The results of genetic polymorphism analysis showed that the genetic differentiation of Apis cerana in central China in different altitude regions of Shennongjia was low(FSTmax=0.0488038<0.05).Honey bee populations from 0 m-500 m and 2500 m-3000 m sampling points were selected to represent the low and high altitude adapted Apis cerana in central China populations in Shennongjia for selection signal annotation analysis.The results of GO annotation analysis showed that the selected genes in Apis cerana in central China in Shennongjia were mainly enriched in biological processes such as catalytic activity,protein synthesis processing transport and cellular respiration;The results of KEGG pathway enrichment analysis showed that the selected genes of Apis cerana in central China in Shennongjia were mainly enriched in metabolic pathways such as lipid metabolism,longevity regulation and EMC-receptor interaction and Foxo,Hippo,m TOR and Hedgehog signal transduction pathways related to temperature adaptation,and screened for FOXO、CYP302AL、CYP303AL、CYP4AA1、CYP4C1、COX7C、ULK3、SOD and SMURF1 were identified as nine candidate genes,which are affected by the altitude temperature environment.These genes are hypothesized to be associated with cold resistance and energy metabolism in honey bees.In summary,the results of morphological analysis showed that the morphology of Apis cerana in central China population differed significantly among different elevations in Shennongjia.The results of gene resequencing analysis showed that no genetic differentiation occurred in Apis cerana in central China population at different elevations in Shennongjia,but there was rich genetic diversity within the population.The scientific use of germplasm resources lies in the prevention of cross-regional introductions,strengthening the protection and expansion of pure BBY and DLT Apis cerana in central China colonies;carrying out rejuvenation and purification of Apis cerana in central China germplasm resources with a high degree of hybridization at an altitude of 500 m-2000 m,and using candidate genes related to cold resistance and energy metabolism of Apis cerana in central China to carry out good breeding work.The results of this study can provide scientific indications for the conservation and utilization of Apis cerana in central China germplasm resources... |
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