【作者】 朱旺生；

【导师】 沈益新；

【作者基本信息】 南京农业大学 ， 动物营养与饲料科学， 2003， 硕士

【摘要】 化感作用是近年来逐步受到世界各国科学家重视的一个研究领域，在生态农业的发展中具有重要的意义。随着农业产业结构的调整及三元种植结构的推广，牧草在农业生产中的作用日益显现。研究牧草的化感作用，对牧草生产的合理安排，提高生产效率具有十分现实的意义。 白三叶(Trifolium repens)和高羊茅(Festuca arundinacea)分别为豆科和禾本科的常用高产优质牧草。近年来，随着种草养畜的发展，这两种牧草在农区的种植面积迅速扩大。旨在为农业生产中合理安排茬口，避免牧草化感作用的不利影响，本研究用白三叶和高羊茅的水浸提溶液进行了四季红萝卜(Raphanus sativus)、绿星青菜(Brassica chinensis)和沃土多花黑麦草(Lolium multiflorum)的种子发芽和幼苗生长试验，从受体植物的组织切片、酶测定及供体植物水浸提液中的化感物质分析等几个方面探讨了白三叶和高羊茅化感作用的效应，并比较了白三叶和高羊茅化感作用的种间及品种间差异。 试验结果表明，各品种浸提液处理对受体植物种子萌发和幼苗生长具有明显的抑制作用；不同白三叶和高羊茅品种对受体植物的化感作用存在明显的种间和品种间差异；化感抑制对不同受体植物种及幼苗各器官生长的抑制程度亦存在较大的差异。 对白三叶和高羊茅化感物质进行的初步分析结果表明，白三叶和高羊茅化感物质中含有较多的邻位和间位羟基的酚类物质，化感物质显著抑制受体植物的细胞生长。各受体植物幼苗不同部位的切片观察表明，经白三叶和高羊茅茎叶浸提液处理的幼苗细胞排列较对照紧密，细胞体积有缩小趋势。受体植物幼苗体的超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的测定结果显示，经白三叶和高羊茅浸提液处理的受体植物幼苗组织SOD活性降低，MDA含量升高，表明白三叶和高羊茅茎叶浸提液处理使受体植物细胞膜的功能受到影响。 白三叶和高羊茅化感作用的效应相同，但白三叶的化感作用能力大于高羊茅；白三叶品种海发的化感作用明显强于其它三个白三叶供试品种，高羊茅品种巴比伦的化感作用亦比其它两个高羊茅供试品种强。白三叶和高羊茅不同生长阶段其化感作用能力亦有差异，化感作用最强的时期为盛花期。 白三叶和高羊茅对四季红萝卜、绿星青菜、沃土多花黑麦草种子发芽和幼苗生长均具有不同程度的化感抑制作用。因此，在生产实践中应根据其化感作用的特点，接茬种植时应慎重考虑后茬作物。更多还原

【Abstract】 Allelopathy has been noticed by scientists all over the world in recent years, and it is an important factor in the development of ecology agriculture. With the adjustment of agriculture structure, forage crops play a vital role in agriculture production. It is needed to understand the allelopathic effect of forage crops for scientific arrangement in forage plant system and improving crop production efficiency.White clover (Trifolium repens) and tall fescue (Festuca anmdinacea) are widely planted because of their high yield and excellent quality. In recent years, the planting area of white clover and tall fescue has rapidly enlarged in farming zone with the development of animal husbandry. In order to discuss the allelopathic potential and its mechanism, the effects of water extracts of white clover and tall fescue on seed germination and seedling growth of radish (Raphanus sativus), greencovery(Brassica chinensis ) and Italian ryegrass (Lolium multiflorum) were studied. The mechanism of allelopathy of white clover and tall fescue was discussed by means of tissue slicing, enzyme mensurating and ailelochemicals analysis, and the difference of allelopathic potential among species and varieties was analyzed.The result indicated that extracts from all varieties significantly inhibited seed germination and seedling growth of the receptors. Allelopathic effects of white clover and tall fescue on the receptors were obviously different among species and varieties. Each receptor and each seedling organ of receptors showed specific response to ailelochemicals, and they were inhibited incoordinately.A preliminary analysis of ailelochemicals showed there were plenty of o-hydroxybenzene and m-hydroxybenzene in white clover and tall fescue. Cell growth of receptors was significantly inhibited by ailelochemicals. Mircostructurc of all organs of the receptors showed the cell array of seedlings became compact and the cell size became small after seedlings were treated with white clover and tall fescue extracts.The avtivity of SOD decreased and MDA content increased after treatment.This suggested that funtion of cell membrane was damaged by allelochemicals.The allelopathic effect of white clover and tall fescue was identical, but the allelopathic potential of white clover was stronger than that of tall fescue. The allelopathic potential of a cultivation Haifa was strongest among four varieties of white clover, and the allelopathic potential of Babian was also strongest among three varieties of tall fescue. Allelopathic potential of white clover and tall fescue changed significantly during different growing stages, and it displayed the strongest allelopathic potential in peak anthesis.White clover and tall fescue inhibited seed germination and seedling growth of radish, greencovery and Italian ryegrass because of their allelopathy. Therefore, the following crops should be arranged scientificly according their traits in production.更多还原