间作大蒜对当归连作障碍的影响及机理研究

Aimed at the problems such as yield reduction, plant diseases and insect pests increase that caused by Angelica sinensis continuous cropping obstacles, effect and its mechanism of intercropping garlic on Angelica sinensis continuous cropping obstacles will be studied. The purpose of the research is to explore the beneficial interspecies effect between Angelica sinensis and garlic, and to alleviate Angelica sinensis continuous cropping obstacles. The effect of garlic plant volatiles and root secretions on Angelica sinensis seed germination and seedlings growth under stress of continuous cropping obstacles will be studied in this project, to test if there is some increase or inhibition between garlic and Angelica sinensis development and metabolism, and define the material sources that caused effect, then to test if the effect is dependent on concentration. The effect of garlic on rhizosphere soil microorganism and soils enzyme activities of Angelica sinensis will be studied to test effect of intercropping garlic on soil suroundings, and then prove that intercropping garlic can alleviate Angelica sinensis continuous cropping obstacles. Combine the effect of adversity resistance physiological and soil surrounding of garlic on Angelica sinensis, the mechanism of garlic on Angelica sinensis continuous cropping obstacles will be explored. It is a guiding role for Angelica sinensis pollution-free cultivation.

针对当归产区连作障碍导致的产量降低、病虫害严重等问题，展开间作大蒜对当归连作障碍的影响作用和机理研究，旨在探索大蒜对当归有利的种间效应，缓解当归连作障碍。本项目通过研究大蒜植株挥发性物质、根系分泌物对连作胁迫下当归种子萌发和幼苗生长的影响作用，验证大蒜是否对当归个体发育和物质代谢存在促进或抑制作用，明确其影响效应的物质来源，并探明其影响效应是否存在浓度依赖；通过研究间作大蒜对连作当归根际土壤微生物和酶活性的影响效应，验证间作大蒜对当归根际土壤环境的影响，进而证明间作大蒜对当归连作障碍的缓解作用；结合大蒜对当归抗逆生理的影响和对土壤环境的影响，明确间作大蒜对当归连作障碍产生影响效应的作用机理。本研究结果对实现当归无公害栽培具有重要指导意义。

项目背景：针对当归产区连作障碍导致的产量降低、病虫害严重等问题，展开间作大蒜对当归连作障碍的影响作用和机理研究，旨在探索大蒜对当归有利的种间效应，缓解当归连作障碍。研究内容：研究大蒜植株挥发性物质、根系分泌物对连作胁迫下当归种子萌发和幼苗生长的影响作用；间作大蒜对连作障碍胁迫当归根际微生物和酶活性、当归生长及产量和质量的影响。重要结果：离体蒜苗挥发物对于当归种子的萌发存在一定的化感促进效应，但当蒜苗挥发物浓度增大到一定值时，当归种子的萌发被抑制；在用不同极性不同浓度大蒜根系分泌物处理后，当归种子发芽势、发芽率和萌动种子中α-淀粉酶活性均较对照增高，极性成分有利于当归出苗整齐，而弱极性成分发芽率较高；大蒜根系分泌物浓度为0.6mg/ml和0.8mg/ml时对当归连作障碍有缓解作用，能够促进当归叶片的叶绿素含量的积累，增强当归叶片的CAT和SOD活性，增强当归的根系活力；离体蒜苗挥发物对当归苗高、根长、地上地下鲜物质积累量及叶片中叶绿素含量都有促进作用，而且在当归:大蒜=1:1时表现出最高值，说明促进作用与蒜苗挥发物浓度有关；当归与大蒜间作能够提高当归的叶片保护酶活性；间作大蒜有利于细菌和放线菌数量的增长，有利于当归根际微生物群落良性发展，当归和大蒜间作对根际微生物的影响主要是通过大蒜的根系或鳞茎分泌物所致；当归/大蒜=2:1的间作模式显著较单作当归麻口病发病率低；当归/大蒜=2:1的间作种植模式显著改善土壤微生物区系、提高土壤养分吸收效率，增加当归自身抗性，有效缓解当归连作障碍，从而提高当归产量质量。科学意义：初步探明了大蒜对当归连作障碍产生影响效应的作用机理，对实现当归无公害栽培具有重要指导意义。