卧龙国家级自然保护区大熊猫主食竹的营养成分与微生物群落结构

Nutrient composition and microbial communities of bamboo at Wolong National Nature Reserve

大熊猫是卧龙自然保护区旗舰物种,自然保护区内覆盖了多种大熊猫主食竹.为研究卧龙保护区不同种类大熊猫主食竹营养成分和微生物群落的组成,采用理化实验和高通量测序技术对保护区内主要的4种大熊猫主食竹进行测定分析.结果显示,不同竹种中均以纤维素(46.18%±2.50%至56.82%±2.2%)、半纤维素(11.74%±2.00%至23.03%±2.74%)和木质素(15.29%±3.31%至22.53%±6.0%)为主要成分,其中半纤维素和木质素的含量不随竹种变化而发生显著变化(P>0.05,Kruskal-Wallis test).纤维素、黄酮和蛋白质的含量在不同竹种中存在显著差异(P<0.05,Kruskal-Wallis test).竹子细菌菌群的丰富度以及真菌菌群的丰富度和多样性在不同竹种间差异显著(P<0.05,Kruskal-Wallis test).Proteobacteria(81.3%)是大熊猫主食竹中主要的细菌门,Pseudomonas(26.2%)是主要的细菌属.Proteobacteria(86.2%)和Pseudomonas(33.9%)在短锥玉山竹中的相对丰度显著高于其余各组(LDA>4).Ascomycota是白夹竹(84.8%)、拐棍竹(48.8%)和冷箭竹(48.8%)最主要的真菌门,而Basidiomycota是短锥玉山竹(60.4%)最主要的真菌门.Cryptococcus是白夹竹(56.4%)、短锥玉山竹(57.4%)和冷箭竹(42.6%)最主要的真菌属,而Rachicladosporium是拐棍竹(11.0%)最主要的真菌属.本研究表明竹种对大熊猫主食竹的营养成分和微生物组成有显著影响;结果对研究野生大熊猫生态以及圈养大熊猫可食竹的选择与投喂有指导意义.

The giant panda is the flagship animal of the Wolong National Nature Reserve,which includes a high cover of many bamboo species in their diet.This study used chemical experiments and highthroughput sequencing to investigate the nutrition provided by and microbiota composition of the four main diet bamboo species preferred by giant pandas in Wolong.The results showed that cellulose(46.18±2.50%to 56.82±2.2%),hemicellulose(11.74±2.00%to 23.03±2.74%),and lignin(15.29±3.31%to 22.53±6.0%)were the main components of bamboo,and no significant differences were found among hemicellulose and lignin between bamboo species(P>0.05,Kruskal–Wallis test).The concentration of cellulose,flavone,and protein varied remarkably(P<0.05,Kruskal–Wallis test)among different species of bamboo.The bacterial richness and fungal richness and diversity in different bamboo species fluctuated markedly(P<0.05,Kruskal–Wallis test).Proteobacteria and Pseudomonas were the predominant bacterial phylum and genus at 81.3%and 26.2%,respectively.The abundances of Proteobacteria and Pseudomonas(86.2%and 33.9%,respectively)in Yushania brevipaniculata were significantly higher than those in the other groups(LDA>4).Ascomycota was the most abundant fungal phylum in Phyllostachys bissetii(84.8%),Fargesia robusta(48.8%),and Bashania fangiana(48.8%),while Basidiomycota(37.7%)was the major fungal phylum in Y.brevipaniculata(60.4%).Cryptococcus(28.0%)was the predominant fungal genus in P.bissetii(56.4%),Y.brevipaniculata(57.4%),and B.fangiana(42.6%)while Rachicladosporium(11.0%)was the predominant fungal genus in F.robusta.In summary,our results indicate that different bamboo species provide significantly different levels of nutrition and have significantly different microbiota compositions.This research provides suggestions for the choice of bamboo species to be fed to captive giant pandas.