【作者】 肖靖秀；

【导师】 郑毅； 汤利；

【作者基本信息】 云南农业大学 ， 植物病理学， 2013， 博士

【摘要】 小麦蚕豆间作是一项传统的种植模式，广泛分布于我国西南地区。生产实践和田间试验均表明，小麦蚕豆间作具有显著的增产、控病优势。现有研究已从地上部的养分、水分吸收利用、碳氮代谢特点、地下部的土壤养分动态特征和根际微生物多样性等方面进行了较多研究，一定程度地揭示了小麦蚕豆间作优势形成的机制。但是，有关间作体系中的根-土-微生物互作的关键物质—根系分泌物，却鲜有报道。在小麦蚕豆间作系统中，根际土壤养分活化、根际微生物和土传病害的发生均与间作措施密切相关，但其具体作用机制并不清楚。因此，本研究通过盆栽（土培）试验和水培试验，收集根系分泌物，采用化学分析结合高效液相色谱，分析测定了小麦蚕豆间作条件下不同生育期作物的养分吸收和根系分泌物中有机酸、酚酸、氨基酸和糖；同时，通过接种试验，比较了单间作蚕豆根系有机酸分泌对蚕豆枯萎病病原菌响应的差异。主要研究结果如下：（1）小麦蚕豆间作具有显著的生物量优势，土培和水培条件下，间作生物量土地当量比（LER）分别为1.12和1.04。与单作相比，间作提高了蚕豆根冠比、提高了小麦和蚕豆的根系活力及生殖生长阶段蚕豆的生物量。在小麦蚕豆成熟期前后，间作有提高小麦蚕豆氮磷养分吸收累积的趋势。间作显著促进了氮素养分向蚕豆籽粒及茎叶中转移、促进了磷素养分向蚕豆籽粒中转移。（2）小麦蚕豆间作提高了根系有机酸的分泌量。土培结果表明，在小麦分蘖期、孕穗期、灌浆期，间作分别提高了小麦根系有机酸分泌量155%、35.6%和92.6%；在蚕豆分枝期、籽粒膨大期，间作提高蚕豆根系有机酸分泌量87.4%和38.7%。水培结果表明，在蚕豆开花期，间作根系有机酸分泌量是单作蚕豆的1.5倍。（3）小麦蚕豆间作改变了根系分泌物中有机酸的种类。土培结果表明，在小麦分蘖期及拔节期，间作小麦根系分泌物中增加了柠檬酸和乳酸，减少了乙酸；在蚕豆分枝期，间作蚕豆根系分泌物中增加了乙酸，减少了乳酸；在籽粒膨大期，间作蚕豆根系分泌物中增加了乳酸，减少了富马酸。水培结果表明，在小麦孕穗期，间作根系分泌物中增加了富马酸；在蚕豆分枝期，间作根系分泌物中减少了草酸；在蚕豆开花期，间作根系分泌物中增加了草酸、酒石酸、柠檬酸和富马酸；在蚕豆结荚期，间作根系分泌物中增加了酒石酸。（4）小麦蚕豆间作提高了小麦根系分泌物中不同种类有机酸的分泌速率。土培结果表明，在小麦孕穗期，间作小麦柠檬酸和富马酸的分泌速率是单作的179倍和184倍；在小麦灌浆期，间作小麦乳酸的分泌速率是单作的2.53倍。水培结果表明，在拔节期，间作小麦柠檬酸和富马酸的分泌速率是单作的4.6倍和3.2倍。（5）小麦蚕豆间作降低了根系分泌物中酚酸的总量和分泌速率、减少了酚酸的种类。与单作小麦相比，在小麦分蘖期、拔节期、孕穗期，间作根系酚酸分泌量分别下降64.6%、70.01%和39.0%；间作降低了对羟基苯甲酸、香草酸和丁香酸的分泌速率。与单作蚕豆相比，在蚕豆分枝期、开花期，间作根系酚酸分泌量分别下降37.6%和57.8%。在分枝期和开花期，间作抑制了香草酸和对羟基苯甲酸的分泌。同时小麦蚕豆间作减少了小麦根际土中酚酸的累积，改变了蚕豆根际土中酚酸的种类。（6）小麦蚕豆间作提高了氨基酸的分泌量。全生育期，间作提高蚕豆根系氨基酸分泌量19.6%~75.9%。间作蚕豆根际土中氨基酸含量是单作的1.9~7.6倍，同时间作显著提高了拔节期、孕穗期小麦根际土中氨基酸的含量。（7）小麦蚕豆间作提高了根系糖的分泌量。土培结果表明，在拔节期、孕穗期、灌浆期，间作提高小麦根系总糖分泌量126.9%，34.9%和59.8%，其中间作小麦蔗糖分泌量是单作的2.37倍，1.41倍和2.0倍。水培结果表明，在蚕豆分枝期、开花期、结荚期，间作根系总糖分泌量是单作蚕豆的3.16倍，2.78倍和3.92倍；其中间作根系还原糖、蔗糖的分泌量分别是单作蚕豆的2.58倍、3.68倍、3.31倍和3.42倍、2.45倍、4.57倍。（8）尖孢镰刀菌侵染蚕豆后，小麦蚕豆间作降低了蚕豆枯萎病发病率及病情指数，降低了蚕豆根系及根际土中有机酸的总量。间作通过显著降低根际土中柠檬酸和苹果酸的含量来降低枯萎病的发病率及病情指数。更多还原

【Abstract】 Wheat and faba bean intercropping is a traditional agricultural practice which is widelyadopted by farmers in southwest China. Results from agriculture production and numerous fieldtrials showed that wheat and faba bean intercropping could significantly improve crop yields anddecrease diseases incidence. Characteristics of nutrients uptake, water absorption, carbon andnitrogen metabolisms, dynamic changes of rhizosphere available nutrients and rhizospheremicrobe flora and yield advantages in wheat and fababean intercropping have been stated in manypublications. However, little about the characteristics of root exudates in this intercropping areknown. Root exudates play an important role in rhizhosphere micro-ecological environment andagro ecosystem. In wheat and faba bean intercropping, there are close correlations betweenintercropping and soil nutrients mobilization, growth of rhizosphere microorganisms and soil borndiseases. But the reasons are still unclear. In this studies pot trials and hydroponic cultures ofwheat and faba bean intercropping were carried out, exudates from the roots were collected andexamined by HPLC and chemical analysis to investigate the types and amounts of organic acids,phenolic acids, ammonia acids and sugar during crop different growth stages. Meanwhile,responses of organic acids in root and rhizosphere to fusarium oxysporum infection inintercropping were analyzed. The main results are as follows:(1)Wheat and faba bean intercropping（W//F）were of significantly yield (biomass)advantages. The land equivalent ratio (LER) was1.12and1.04in pot and hydropoinc culturerespectively. W//F increased root/shoot ratio of faba bean in comparison with that of monocropedfaba bean(MF), and both root activity of wheat and faba bean increased in intercropping.Meanwhile, there was increase trend of N and P uptake and accumulation in intercropping duringharvest stage in comparison with that of monocropping. Intercropping also increased N and Ptranslocation from roots to seeds of faba bean.(2) W//F increased total amount of organic acids (OA) in root exudates (RE) in comparisonwith that of monocropping. In pot culture, the total amount of OA in RE of intercroppingwheat(IW) was increased by155%、35.6%and92.6%at tilering, booting and filling stagerespectively in comparison with mono cropping wheat (MW). And total amount of OA in RE ofintercropping faba bean (IF) was increased by87.4%and38.7%at branching and filling stagerespectively in comparison with mono cropping faba bean (MF). In hydroponic culture, the totalamount of organic acids in RE of W//F was1.5times higher than that of MF at flowering stage.(3) W//F changed types of OA in RE in comparison with that of monocropping. In pot culture,lactic and citric acid was detected in RE of IW at tilering and jointing stage of wheat, but that wasnot detected in that of MW. At branching stage of faba bean, acetic acid was detected in RE of IF,wherea lactic acid was detected in RE of MF.At filling stage of faba bean, lactic, acetic and citic acid was detected in RE of IF, whereas acetic, citic and fumaric acidbut was detected in that ofMF.In hydroponic culture, fumaric acid was detected in RE of W//F at booting stages, but that wasnot detected in that of MW. And oxalic, tartaric, citric and fumaric acid was detected in RE ofW//F, but not detected in MF at flowering stage.(4)W//F increased root exudation rate of organic acids in comparison with that of monocropping. In pot culture, exudation rate of citric and fumaric acid of IW was179times and184times higher than that of MW at booting stage respectively. And exudation rate of lactic acid ofIW was2.53times higher than that of MW at filling stage. In hydroponic culture, exudation rateof citric and fumaric acid of IW was4.6times and3.2times higher than that of MW at jointingstage respectively.(5)In comparison with monocropping, W//F decreased total amount and types of phenolicacids (PA) in RE, and declined exudation rate of PA. W//F decreased total amount of phenolicacids(PA) in RE by64.6%、70.01%and39.0%at tilering, jointing and booting stage respectivelyin comparison with that of MW. And W//F decreased total amount of PA in RE by37.5%and57.79%at branching and flowering stage respectively in comparison with that of MF. Exudationrate ofρ-hydrobenzoic，vanillic and syringic acid was decreased in intercropping during thewhole growth stages in comparison with that of MW. Vanillic and ρ-hydrobenzoic acid wasdetected in RE of MF at branching and flowering stage of faba bean, but that was not detected inthat of W//F.PA content of IW rihzosphere decreased in comparison with that of MW, andintercropping changed types of PA in rhizsophere in comoparison with that of MF.(6)Intercropping improved total amount of amino acids (AA) in RE in comparison with thatof monocropping.Total amount of AA in RE of IF was increased by19.6%~75.9%during thewhole growth stages in comparison with that of MF, and total amount of AA in rhizosphere of IFwas1.9times~7.6times higher than that of MF. Meanwhile, W//F significantly increased totalamount of AA in rihzosphere of IW at jointing and booting stages, compared to MW.(7) In comparison with monocropping, W//F increased total amount of sugar in RE. In potculture, total amount of sugar in RE of IW was increased by126.9%，34.9%and59.8%atjointing, booting and filling stage respectively compared to MW. At the same time, sucrosecontent in RE of IW was2.37times,1.41times and2.0times higher than that of MW respectively.In hydropoinc culture, total amount of sugar in RE of W//F was3.16times,2.78times and3.92times higher than that of MF at branching, flowering and booting stage respectively.Meanwhile, both reduce sugar and sucrose content in RE of W//F was higher than that of MF.(8) Fababean fusarium wilt incidence and severity index were decreased in intercropping incomparison with that of monocropping, and total amount of AA in faba bean root and rhizospherewere decreased too in intercropping after Fusarium oxysporum injection. In comparison with MF,intercropping significantly decreased content of citric and malic acid in rhizosphere and resulted in decreasing of fusarium wilt incidence and severity.更多还原