长足大竹象种群数量的自然调控机制

Cyrtotrachelus bugueti is a sympodial bamboo borer pest. It is seriously harmful, extremely concealment and difficult to control. However, the damages are significantly different in different ecosystems of bamboo forests. The damages are very serious in million acres of bamboo forests in Leshan, Sichuan province, but there is no harm in 1.23 million acres in Chishui,Guizhou province. It shows that there exist natural regulatory roles to the pest population in ecosystem of bamboo forests. The research of this regulatory mechanism has great significance for ecological control. The project takes the population of Cyrtotrachelus bugueti in bamboo forest ecosystem of two places and transition zone as research subject. Amplifying the sequences of mitochondrial Cyt b gene and D-loop control region, we will analyse contrastively population genetic variation of Cyrtotrachelus bugueti in different bamboo forest ecosystems. Applying GC-MS, EAG and scanning electron microscopy and so on, we will study three trophic interactions among host sympodial bamboo shoot, Cyrtotrachelus bugueti and predators. It will be investigated and analyzed that environmental factors based on temperature, soil structure, moisture ect, and farming system control the Cyrtotrachelus bugueti population in order to reveal the reasons why exist differences in damages of Cyrtotrachelus bugueti in different bamboo forest zones. The low level and natural regulation of population in Cyrtotrachelus bugueti will be researched. The research puts forward ecological control modes to provide theoretical support to ecological control, harmless bamboo nurture and artificial afforestation .

长足大竹象是丛生竹的钻蛀害虫，危害严重，隐蔽性极强，难于防治。然而，该虫的危害在不同的竹林生态系统中差异显著，四川乐山百万亩丛生竹林危害严重，贵州赤水123万亩丛生竹林却无危害，显示竹林生态统对该虫种群存在自然调控作用，研究此调控机制，对长足大竹象生态防控意义重大。本项目以两地及其过渡区竹林生态统长足大竹象种群为研究对象，通过线粒体Cyt b基因和D-loop控制区扩增测序，对比分析不同竹林生态系统长足大竹象种群遗传变异；应用GC-MS、EAG、电镜扫描等技术，研究寄主丛生竹笋-长足大竹象-天敌三级营养互作关系；调查分析不同竹林系统内温度、土壤结构、水分等环境因子及耕作制度对竹象种群的控制作用，揭示不同竹林区长足大竹象危害差异的原因，探究其种群数量的低水平成因和自然调控机制，提出该虫的生态防控模式，为长足大竹象生态防控、竹林的无害化培育、人工造林提供理论支撑。

长足大竹象是丛生竹的毁灭性害虫，四川乐山百万亩丛生竹林危害严重，贵州赤水 123 万亩丛生竹林却无危害，显示竹林生态统对该虫种群存在自然调控作用。本项目采用定点观察、基因组测序、转录组分析及电镜扫描、GC-MS等技术，首次对长足大竹象进行了系统研究，分析了长足大竹象种群密度的调控和变化机制、竹笋与长足大竹象种群的互作及区域环境因素对长足大竹象种群的影响；项目完成长足大竹象全基因组测序工作，从基因水平揭示了长足大竹象种群发育及其与竹笋纤维的互作机制；用4年的时间采集了全国13个省共75个地区重点竹区的长足大竹象、直锥大象资源，积累了全国最丰富的竹象资源。项目取得丰硕成果，共完成论文19篇，已发表的6篇、已接收的2篇、修改稿11篇，其中英文论文11篇、Biotechnology for Biofuels等国际权威期刊3篇、影响因子累计20分以上；出版《长足大竹象》专著1部；获授权发明专利2项、实用新型2项；获四川省科技进步奖2项，其中二等奖1项、三等奖1项；成果应用累计产生社会纯收入2亿以上。项目成果为长足大竹象生态防控、培育竹资源及竹纤维资源的利用提供了强有力的理论支撑。长足大竹象研究达到世界领先水平。