小麦蚕豆间作缓解蚕豆连作障碍的机理研究

Fusarium wilt of faba bean is one of the most widespread and destructive soil-borne fungal diseases because of continuous monocropping, which has severely reduced yield, quality and limited faba bean production. Nowadays it is difficult to control the disease by conventional chemical control strategies in field production. Intercropping systems have a long history in crop production in China, and have widely accepted as a sustainable practice due to its yield advantage and disease suppression. Numerous studies on intercropping have mainly focused on yield advantage and control of wind-dispersed diseases, but little information is known about mechanism for controlling soil-borne diseases by intercropping, especially no reports have confirmed whether and how autotoxic substances of phenolic acid were involved in the pathogenic impact of Fusarium oxysporum in intercropping system. Our previous researches have showed that wheat and faba bean intercropping significantly increased the total amount and diversity of microbes, controled fusarium wilt of faba bean. Recent studies showed that autotoxic substances could promote occurrence of soil-borne diseases and lead to serious replant obstacles. Therefore, the objectives of this study are to examine the alleviating effects of intercropping on autotoxicity; effects of intercropping on composition and content of autotoxic substances which come from faba bean root exudates, residues and soil; phenolic acids - rhizosphere microbes - pathogen interaction effect in intercropping system and its role in continuous cropping obstacles alleviating under hydroponics, greenhouse and field conditions, to reveal the mechanism of alleviating autotoxicity and suppressing Fusarium wilt by intercropping. The results of this study will help to establish the theory foundation for using biodiversity as means to increase crop yield, improve disease control and achieve agricultural sustainable development.

蚕豆连作导致土传枯萎病普遍发生，严重制约我国的蚕豆生产，目前生产中尚无有效的化学防治措施。合理间作能显著增加作物产量，而且是持续控制病害的有效措施，长期以来，间作研究主要集中在产量优势和对气传病害控制方面，对间作控制土传病害的机制研究较少，尤其是间作系统土传病害控制与自毒物质变化的关系及作用机制尚缺乏系统研究。最近研究显示，自毒物质能促进土传病害发生并导致严重的连作障碍。我们的前期研究表明，小麦蚕豆间作显著增加了微生物数量和多样性并控制了枯萎病的发生。因此，本项目拟以云南普遍种植的小麦蚕豆间作体系为研究对象，通过水培、土培和大田试验研究间作对蚕豆自毒作用的缓解效果，间作对自毒物质酚酸组分与含量的影响，间作系统酚酸-根际微生物-病原菌的互作效应及其在连作障碍缓解中的作用。揭示间作减轻自毒作用，缓解连作障碍的机制，为应用生物多样性持续控制作物病害，实现农业可持续发展提供理论依据。

蚕豆连作导致土传枯萎病普遍发生，严重制约我国的蚕豆生产，目前生产中尚无有效的化学防治措施。长期以来，间作研究主要集中在产量优势和对气传病害控制方面，有关间作系统土传病害控制与自毒物质变化的关系及作用机制尚缺乏系统研究。小麦蚕豆间作是云南普遍的种植模式，在云南粮食增产和作物病害控制中发挥着重要的作用。本项目通过水培、土培盆栽和田间试验研究了小麦蚕豆间作对蚕豆自毒作用的缓解效果，间作对自毒物质酚酸组分与含量的影响，揭示了间作减轻自毒作用，缓解连作障碍的机制。. 研究表明，蚕豆植株水浸液、腐解物和根际土浸提液抑制了蚕豆种子萌发和幼苗生长，促进了尖孢镰刀菌孢子萌发和菌丝生长，而小麦能缓解蚕豆的连作自毒作用。蚕豆根系分泌物中检出7种酚酸，以水杨酸、肉桂酸和苯甲酸的含量较高，小麦与蚕豆间作显著抑制了酚酸的分泌。酚酸胁迫降低了蚕豆根际微生物的多样性，促进病原菌的增殖，加剧了蚕豆枯萎病的发生，证实了酚酸累积是诱导蚕豆连作障碍形成的初始诱因。小麦与蚕豆间作显著提高了蚕豆根际微生物的活性和多样性，降低了蚕豆根际土壤中对羟基苯甲酸、香草酸、丁香酸、阿魏酸、苯甲酸和肉桂酸的含量，减少了土壤中镰刀菌的数量，从而减轻了枯萎病的危害程度。间作缓解连作障碍与根际微生物⁃酚酸-病原菌的互作密切相关。本研究结果为进一步深入揭示间作种植缓解作物连作障碍，提高作物产量，实现农业可持续发展提供了重要的科学依据。通过项目实施，发表学术论文19篇，其中期刊论文17篇（一级学报论文11篇，核心期刊论文 6篇），会议论文2篇。获国家发明专利授权1项；出版学术专著1部。培养硕士研究生6人，项目组成员1人获云南农业大学“百名青年学术和技术带头人”称号，2人公派赴荷兰wageningen大学进行学术研究，2人晋升高一级职称，1人考取博士研究生。举办学术会议1次，参加国内外相关学术会议21人次。.