转地蜂群病原微生物及肠道共生菌的变化

The Variation of Pathogens, Parasites and Symbionts in Migratory Honeybees (Apis mellifera ligustica)

【目的】探明转地放蜂过程中常见蜜蜂病毒和寄生虫的流行规律,及不同地区工蜂肠道中两种主要共生菌Gilliamella apicola和Snodgrassella alvi的变化情况。【方法】在转地放蜂过程中,对同一意大利蜜蜂(Apis mellifera ligustica)蜂场的固定蜂群连续取样,采用RT-PCR方法检测蜂群中病毒和寄生虫的感染情况,使用SPSS 17.0软件对不同地区、不同季节样本的病毒和寄生虫感染率进行卡方检验。以蜜蜂β-actin为内参基因,对不同地区样本中的共生菌G.apicola和S.alvi进行荧光定量PCR分析,检测转地过程中工蜂肠道中这两种细菌的变化情况,并采用Kendall Rank相关系数对病原物感染率和共生菌含量进行相关性分析。【结果】转地放蜂7个地区的样本中,仅检测出以色列急性麻痹病毒(IAPV)、黑蜂王台病毒(BQCV)和蜜蜂残翅病毒(DWV)3种蜜蜂病毒。其中IAPV和BQCV在所有地区均有检出且感染率较高,不同地区之间感染率差异显著;DWV感染率相对较低,不同地区之间感染率差异极显著。西方蜜蜂微孢子虫(Nosema apis)在各地区样本中均未检出,东方蜜蜂微孢子虫(Nosema ceranae)在4个地区的样本中检出,且不同地区间感染率差异极显著,熊蜂微孢子虫(Nosema bombi)在各个地区均有检出,不同地区间感染率差异显著;季节性差异分析表明,IAPV在不同季节的感染率差异不显著,而BQCV、DWV、N.ceranae和N.bombi在不同季节的感染率差异显著,且春夏季的感染率普遍高于秋冬季;不同转地地区的工蜂肠道内均含有共生菌G.apicola和S.alvi,且两种共生菌含量在不同地区间均差异极显著;相关性分析表明,S.alvi和IAPV之间呈显著负相关作用。【结论】转地蜂场工蜂病原微生物的检测结果表明IAPV、BQCV、DWV和微孢子虫在蜂群中普遍存在;蜜蜂病原物的感染率和肠道共生菌的含量在不同地理区域间差异显著;部分病原物与肠道共生菌间呈显著负相关关系;转地放蜂方式对蜜蜂的健康状况有一定影响。

【Objective】The objectives of this study are to examine the occurrence and prevalence of viruses and parasites in migratory honeybees, Apis mellifera ligustica, and to analyze the variation of two main symbiotic bacteria Gilliamella apicola and Snodgrassella alvi.【Method】The virus and parasite infections were detected by RT-PCR in the same colony of A. m. ligustica at different migratory locations. The infection rate of virus and parasite in different regions and seasons were analyzed by chi-square test. The honey bee β-actin gene was selected as the reference gene, the quantitative real-time PCR(q PCR) was used to explore the quantity variation of symbiotic bacteria G. apicola and S. alvi in the different regions, and the Kendall Rank correlation coefficient was used to analyze the correlation between the rate of pathogen infection and the quantity of symbiotic bacteria.【Result】In the seven regions, three viruses were found: Israeli acute paralysis virus(IAPV), Black queen cell virus(BQCV), and Deformed wing virus(DWV). The infection rates of IAPV and BQCV were higher in all regions, and the difference was significant among different regions. DWV infection rate was relatively low, and the infection rate among different regions was extremely significant. Nosema apis was not detected in all the samples. N. ceranae was detected in four regions and the infection rate was extremely significant among different regions. N. bombi was detected in all regions and the infection rate among different regions was significant. The results showed that the infection rates of IAPV was not significantly different in different seasons, but the DWV, BQCV, N. bombi and N. ceranae infection rates had significant differences in different seasons, and the infection rate in spring and summer was significantly higher than that in autumn and winter. The q PCR result showed that G. apicola and S. alvi were detected in all migratory beekeeping periods, and the difference of the two symbiotic bacteria in different regions was extremely significant. There was a significant negative correlation between the prevalence of S. alvi and IAPV. 【Conclusion】The results showed that IAPV, BQCV, DWV and microsporidia are prevalent in the migratory colonies. The infection rate of bee pathogens and the quantity of symbiotic bacteria are significantly different among different geographical areas; there are negative correlations between the incidence of some pathogens and the quantity of some symbiotic bacteria; migratory beekeeping has negative impacts on worker longevity and colony health.