【作者】 陈祥旭；

【导师】 林文雄；

【作者基本信息】 福建农林大学 ， 生物化学与分子生物学， 2005， 硕士

【摘要】 利用化感作用控制农田杂草可减少除草剂的投入,降低环境污染。因此,作物化感作用己成为近年来备受世界各国科学家重视的一个前沿研究领域。本研究以289份来自不同国家利地区的大麦品种为材料,运用“琼脂迟播共培法”进行化感潜力评价,并通过田间试验考察其抗草性能和农艺性状。以欧氏距离作系统聚类分析,从供试材料中选择有代表性的65份材料进行综合评价和遗传多样性研究。结果如下: 1.供试材料中有36个品种（约占总数12.5%）显示山较强的化感作用潜力,但其田间抗草性能表现差异较大,部分品种如M24、星胜、永2176等在田间表现出较大的抗草性能。说明大麦品种间的化感作用潜力存在较大的基因型差异,其化感作用特性会受环境因素的影响。 2.65份大麦材料的系统聚类分析结果表明,当取值D=10.8时可将其分成6类。其中第Ⅱ类群有17个品种,此类群属具有强化感作用特性类群。第Ⅱ₂亚类的三个品种的抑制率都超过80%,可作为化感作用研究中的供体材料和化感抗草品种选育的种质资源加以利用。第Ⅲ₃亚类的三个品种如凡18、CM67 H0651和M13化感潜力均较弱,属弱化感类群,可作为化感作用研究中的对照（供体）材料。 3.80个ISSR引物中,有11个引物可扩增出清晰且具多态性的条带。这11个引物对65个大麦品种共扩增到155条带,分子量为240～2000bp,其中多态性条带137（约占88.4%）条,平均每个引物产生的多态性条带的数目为12.5条。遗传相似系数变异范围为0.35～0.98,平均为0.76.ISSR标记可将所有材料完全区分开,是研究化感大麦种质资源遗传多样性一种有效的分子标记技术。 4.基于ISSR标记数据的聚类结果表明,65份大麦品种材料以遗传相似系数0.75为截值,可分成7个类群,即1个大类群和2个小类群,以及4个单一品种自成体系的个类。归类结果有较明显的地理相关性和遗传类型的趋同性,初步揭示了大麦化感种质资源的遗传多样性。部分具有较强化感作用潜力的大麦品种亲缘关系很近,表明控制其化感作用性状的基因可能是等位的相同基因。而部分化感潜力等异显著的品种聚为一类,这可能与长期定向选择造成化感性状丢失,化感性状的遗传基础日益狭窄有关。更多还原

【Abstract】 The application of allelopathy is an alternative weed control method that could be incorporated into integrated weed management package, thereby reducing over-reliance on herbicides and decreasing environmental pollution. Research in this area has been receiving increasing attention in the world. In this paper, a laboratory screening was conducted to study the allelopathic potential of 289 spring barley accessions from home and abroad by RCA bioassay method. Then the ability of weed-suppressing and agronomic characters were evaluated in the field. Genetic diversity of 65 representive barley varieties was estimated using ISSR markers. The results were summarized as follows:1. Of 289 barley accessions, 36 accessions showed strong allelopathic potential by significantly inhibiting root growth of Lettuce(Lactuca sativa L.) in the laboratory screening.One accession inhibited the growth of receiver plant by 91.5%, whereas 35 other accessions caused growth inhibition by more than 70%.53 cultivars were found to strongly suppress weed growth in the fields. Several cultivars such as M24、 Xingsheng and Yong 2176 performed stong allelopathy potential in the laboratory screening and the same result was found in the field screening.Correlation between the laboratory screening and the field experiment showed that field performance could be predicted to some extent by Lactuca sativa L root length reduction in the laboratory. The result demonstrated that there was a considerable genetic variation of alllelopathic activity in barley germplasms and the alllelopathic activity was easily affected by environment.2. At the level of D=10.8, 65 barley varieties were clustered into six groups.The second group consisted of 17 accessions, showing strongly allelopathic in it, of which 15 ones performed more than70% inhibition in the suppression on the receive plant. They were thought to be a potentially useful source for the research on barley allelopathy and the breeding program for allelopathic cultivars. The third group included 22 accessions which could be divided into 3 subgroups. The third subgroup included 3 accessions such as Fan 18, CM67 H0651 and M13, which averaged 1R value was 31.7%. They still更多还原