藏系绵羊瘤胃古菌季节动态分析

在不同季节分别随机选取3只藏系绵羊,采用PCR-DGGE技术对12只藏系绵羊瘤胃内容物中的细菌区系进行分子生态学分析.对古菌16SrDNA的V2～V4可变区的扩增产物进行DGGE图谱分析、相似性分析和Shannon多样指数分析.结果表明:瘤胃内容物中古菌群落多样性指数冬季与春季间差异不显著(P>0.05),但冬季显著高于夏季(P<0.05),并极显著高于秋季(P<0.01);春季与夏季差异不显著(P>0.05),春季显著高于秋季(P<0.05);夏、秋季之间差异不显著(P>0.05).各季间瘤胃古菌区系组成结构相似性高于94%.冬、春季节,由于牧草中的纤维性物质含量增高,导致瘤胃古菌群落多样性增加,不同季节牧草中粗蛋白和酸性洗涤纤维含量的变化可以引起特异性的古菌群落发育,可能导致不同的优势种群.

Seasonal dynamics of rumen archaeal flora of Tibetan sheep

This experiment was conducted to study the changes of seasonal dynamics of archaeal community in rumen of the grazing Tibetan sheep based on molecular ecology.The PCR and denaturing gradient gel electrophoresis(DGGE) were used to detect the changes of archaeal community in rumen of 12 Tibetan sheep.The V2~V4 regions of the 16SrDNA of rumen archaea and amplified.DGGE profiles of the PCR amplicons were compared by similarity analysis.The results showed that Shannon diversity index of the archaeal community in winter was significantly higher than that in autumn(P<0.01) and summer(P<0.05) and there were no significant differences between winter and spring,spring and summer(P>0.05).Similarity analysis concurred with the DGGE results and showed that archaeal communities were separated from that in winter,spring,summer and autumn.Rumen archaeal community changed with seasonal shift.Similar rates among four seasons were higher than 94%.Diversity of archaeal community increased with the fibre increasing of fodder in spring and winter.The CP and ADF content of forages in different seasons might induce specific archaeal community development,and probably led different predominant species in rumen of the grazing Tibetan sheep.