实葶葱的生物竞争和协同作用与新疆荒漠绿洲农业生态系统中的生物功能

Environmental adaptability and evolution mechanism of plant resources are urgently needed to be solved and the exploration of excellent characters and innovation of germplasm resources are scientific problems in desertification environment. Rational exploitation and utilization of plant germplasm resources and maintaining ecological security are the critical issues because of the fragility of the agricultural eco-environmental in Xinjiang oasis. Allium galanthum, one wild relative species of A. cepa as the research object, only distributes in Xinjiang. Based on the biological competition and cooperation mechanism in the process of natural population regeneration, the study is to clear that the mechanism of growth and distribution pattern of accompanying plants. By means of biogeography, comparison the allelopathic potential ability of plants in the same genus and combination of field habitat and laboratory control techniques, the adaptability and chemical ecological function under the oasis farmland ecosystem are revealed. The repellent effect, special chemical ecological function, allelopathic release pathway and allelochemicals are analyzed. The specificity functions of pests and diseases control and the synergistic changes of chemical ecological function under adverse conditions are discussed. The relationship between the biological competition and the cooperation and the chemical ecological function are evaluated under the oasis farmland ecosystem. The results will lay the foundation for further innovation and excavation of new germplasm with potential of allelopathy and to provide guidance for the maintenance of oasis farmland ecosystem and the sustainable development of agriculture in desert area of Xinjiang.

荒漠环境下迫切需要解决植物资源环境适应性与演化机制、优异种质资源性状发掘与种质创新等科学问题。新疆绿洲农业生态环境脆弱，合理开发利用植物种质资源和维护新疆荒漠环境的生态安全是社会经济发展过程面临的首要问题。本研究以国内仅分布于新疆的洋葱野生近缘种实葶葱为研究对象，运用生物地理方法、同属化感潜势植物比较法、野外生境与实验室控制技术手段相结合，以实葶葱种群自然更新中生物竞争和协同机制为切入点，明确对伴生植物生长及分布格局的影响。通过绿洲农业生态系统下的实葶葱适应性分析，挖掘其生物趋避效应和化学生态调控的功能，掌握其化感物质释放途径和种类，评估其控制农田有害生物功能以及化学生态功能与逆境条件的协同变化规律，探讨绿洲农业生态系统下实葶葱的化学生态功能在维护生态安全的作用，为具有化感潜势的新种质新品种的创新和挖掘奠定基础，为新疆荒漠区绿洲农业生态系统安全维护和荒漠区农业可持续发展提供指导。

通过揭示实葶葱与环境生物因子的互作、协同和竞争规律，探讨实葶葱的绿洲农田生态系统的生态修复功能以及在维护农田生态安全方面的重要作用，重要结果和关键数据如下：.（1）个体繁殖行为表现为有性和无性繁殖多样化特征，年生长发育节律以分蘖形式采取春萌株、秋萌株营养繁殖的方式，正常开花结果，种子具有休眠现象，发芽不整齐。.（2）生物趋避效应观测与评估研究表明，实葶葱种植地伴生植物种类、数量，以及农田杂草、病虫害发生种类与其它农田存在显著差异，生物趋避效应特征明显。.（3）实葶葱根际土壤浸提液、根系分泌物、种子萌发分泌物、植株凋落物、挥发物等对受体植物种子萌发率、幼苗形态、生物量产生显著影响，实葶葱可以通过降雨、喷灌产生的淋溶作用、脱落物降解、分泌等多种途径释放化感物质。.（4）农田有害生物控制功能挖掘研究表明，实葶葱对伴生植物化感作用显著。对病原菌产生抑制作用，并具有一定防效。.（5）实葶葱化感生态效应的受环境干旱和盐胁迫影响，存在促进或抑制的双重效应。.（6）采用GC-ＭS分析显示分别属于醇类（1种）、酯类（5种）、酚类（2种）、酮类（5种）、酰胺类（1种）、烷烃类（9种）、苯类（7种），唑类（5种），以及吡啶、喹啉、亚砜、菲等有机物。