根系分泌物在红壤丘陵区花生连作障碍中的作用机制及化感物质降解菌的筛选

Peanut is currently the most common cash crop in the hilly red soil region of South China, while continuous peanut cropping obstacles occurred widely and has become a restraining factor to sustain the increase of peanut yield and quality. It has been reported largely that root exudates from previous crop takes the role of continuous cropping obstacles. Our previous research have suggested that soil-borne diseases, such as bacterial wilt, were the the mose important reason for continuous peanut cropping obstacles in the hilly red soil region and peanut root exudates included some allelopathic chemicals, such as acetophenone, which could stimulate the pathogenic bacteria of bacterial wilt. In order to make clear the relationship among soil-borne diseases, root secretion and rhizosphere microbe of continuous cropping peanuts, this project improves the gathering installation and the separation method of root secretion; seeks the allelopathic chemicals influencing both the growth of peanut seedlings and the microbial community structure in rhizosphere of continual cropping peanut; identifies the chemical structure by HPLC-MS, GC-MS, NMR and IR; screens the beneficial microorganisms, which can digest the allelopathic chemicals; and applies them and Endophytic Bacteria Strain BZ6-1 in the continuous peanut cropping field to carry out the bioremediation experiment. Through all these attempt, this project aims to give useful theoretical and practical guidance for the prevention and control of continuous peanut cropping obstacles in the hilly red soil region.

花生是南方红壤丘陵区的主要经济作物和油料作物。由于气候原因和经济利益的驱使，花生连作现象较为普遍。然而，长期连作易导致花生生长受抑、产量降低和品质下降，连作障碍已成为制约该区域花生持续高产的重要因素。通过前期研究表明花生青枯病是花生连作障碍的重要因素之一。大量研究表明土传病害的发生与前茬作物根系分泌物密切相关，前期预实验研究发现花生根系分泌物苯乙酮（acetophenone）能够促进青枯病原菌的生长。本项目从花生根系分泌物着手，通过改进的花生根系分泌物收集装置和优化的有机物分离纯化方法，深入研究花生根系分泌物对花生自毒作用以及对连作花生根际土壤病原微生物有化感作用的物质；应用液质联用仪、气质联用仪、核磁共振波谱和红外光谱鉴定其化学结构。这些研究成果为红壤丘陵区花生连作障碍的治理提供了理论基础。

花生是南方红壤丘陵区的主要经济作物和油料作物。由于气候原因和经济利益的驱使，花生连作现象较为普遍。然而，长期连作易导致花生生长受抑、产量降低和品质下降，连作障碍已成为制约该区域花生持续高产的重要因素。通过前期研究表明花生青枯病是花生连作障碍的重要因素之一。大量研究表明土传病害的发生与前茬作物根系分泌物密切相关。本项目从花生根系分泌物着手，通过改进的花生根系分泌物收集装置和优化的有机物分离纯化方法，深入研究花生根系分泌物对花生自毒作用以及对连作花生根际土壤病原微生物有化感作用的物质；应用液质联用仪、气质联用仪、核磁共振波谱和红外光谱鉴定其化学结构。这些研究成果为红壤丘陵区花生连作障碍的治理提供了理论基础。