【作者】 郭洪参；

【导师】 李长松； 张广民；

【作者基本信息】 山东农业大学 ， 植物病理学， 2009， 硕士

【摘要】 山东省的花生种植面积比较大,是中国花生主要的生产和出口基地。近几年,花生颈腐病越来越重,在山东花生主要种植区已造成相当大的经济损失。根据调查,发现花生幼苗和衰老花生包括荚果特别容易受到侵染。一般田块平均发病率5%¹0%,在发病严重的地块可高达50%以上,已成为花生生产上的主要病害之一,严重影响了花生的产量和品质。为了更好地控制病害的发生,本论文主要研究了以下几个方面的内容:1. 2007²008年,采集山东省的13个县（市）苗期和成株期发病花生样本。通过室内分离发现病害主要是由颈腐病病菌引起的。选择了其中6个不同地方的菌株进行致病性测定,发病症状与田间病株症状一致,再分离得到了同一种病原物。根据病原菌的形态特征,并结合其rDNA-ITS区域的序列分析,确定引起山东花生颈腐病的病原菌是棉色二孢（Diplodia gossypina）异名为Lasiodiplodia theobromae和Botryodiplodia theobromae。2.对花生颈腐病病菌（D. gossypina）进行了生物学特性的研究。结果表明:花生颈腐病菌在PDA培养基上生长最好,菌丝生长的最适pH值为4⁸,最适生长温度为28³0℃,在35℃高温下培养能够产生红色色素使培养基变粉红色。光照对菌丝生长的影响不大,但是长时间光照有利于子实体的形成。菌丝的致死温度为52℃处理10min。3.通过5种不同的接菌方法试验,结果表明牙签接种比较适合在温室内对花生品种进行抗性鉴定的接种。采用简单可靠的牙签接种法在温室内对14个花生品种（系）进行抗性鉴定结果表明,几乎所有供试花生品种（系）表现感病,而仅有一个品种表现中度抗病。4.室内采用生长速率法测定了9种杀菌剂和6种除草剂对花生颈腐病菌（D. gossypina）的毒力作用效果。结果表明,常用杀菌剂对花生颈腐病病原菌毒力非常强。除草剂对病原菌的毒性差别很大。其中,高盖草克最好,EC50为33.2529μg·ml^-1。最差的是精稳杀得,EC50高达971.5540μg·ml^-1。5.对山东省花生颈腐病的调查研究结果表明,该病在花生主产区苗期发病率高,主要危害茎基部及分枝,并与土质、气候、栽培方式密切相关。一般有两次发病高峰期,第一次出现在6月中旬,全省花生主产区普遍发生。8月中下旬以后,随着植株衰老,病情缓慢上升进入第二个发病高峰期。田间试验表明好力克+多菌灵、腈菌唑+多菌灵、甲基托布津和百泰防治效果分别为92.36%、76.74%、79.8%和78.35%。更多还原

【Abstract】 Shandong Province, which has bigger plant area of peanut, is the biggest produce and export base of peanut in China. In recent years, peanut collar rot was more and more serious in the main producing areas of peanut, caused considerable economic losses in Shandong Province. According to the survey, we found that peanut seedings and older plants including pods are subject to attack. The rate of diseased plant was 5% to 10% in the field on average,in the serious diseased field,which was more than 50%.So the disease has been one of the serious diseases in peanut culture in Shandong Province, seriously influenced the output and quality. In order to find out pathogens and control the diseases,the following aspects were studied in this thesis:1. During 2007 to 2008, seedings and mature plants of diseased peanut were collected from thirteen counties in Shandong Province. The result of isolation showed that the disease was mainly caused by Diplodia sp.. Six isolates from different location were selected from isolates for pathogenicity tests.The symptom developed on the inoculated plants was consistent with that in field.And the same pathogen was consistently re-isolated from infected plants. According to its characteristics of morphology and sequence analysis of the internal transcribed spacer region of the ribosomal DNA （ITS）, the pathogen causing peanut collar rot in Shandong province was identified as Diplodia gossypina （synonyms Lasiodiplodia theobromae and Botryodiplodia theobromae）.2. The study of pathogen’s biological characterizeation showed that the optimum medium is PDA, the optimum pH was 4.0-8.0,the optimum temperature was 28-30℃for mycelial growth, the pathogen can grow and turn pink at 35℃on PDA.Different lighting time had no significant effect on mycelial growth, but The pathogen produced pycnidium more quickly under the condition of continuous fluorescent light.The lethal temperature of the mycelium was 52℃for 10 min.3. Five inoculation techniques of peanut on D. gossypina were tested in greenhouse.The results showed that the toothpick technique were the most effective methods to inoculate peanut in greenhouse for resistance evaluation. The resistance test on fourteen peanut cultivars performed by the toothpick technique in greenhouse for its reliable and easy. It showed that almostly all peanut cultivars were susceptible to peanut collar rot. However, only one cultivar exhibited weakly moderate resistance among the cultivars.4. Nine fungicide agents and six herbicides were tested to determine the toxicity effects on D. gossypina in the laboratory. The results showed that common fungicides remarkably inhibited the mycelial growth of D. gossypina. The studies of six herbicides on D. gossypina in vitro showed that toxicity of six herbicides to D. gossypina was different. Toxicity of haloxyfop-R-methyl is best and the worst is fluazifop-p-butyl,with EC50 are 33.2529μg·ml^-1 and 971.5540μg·ml^-1 respectively.5. Investigation and study on peanut collar rot in Shandong Province carrying out, the result showed that the disease has a high incidence in the main producing areas of peanut in seedling, mainly harms the basal stems and its branches, which has a closely relation with soil, climate and way of cultivation. There are usually two peak disease period and the first one usually appears in mid-June in the province’s main producing areas. After mid and late August, with the plant senescing, disease index increases slowly and enters the second peak of disease. The field test showed that the control1 effects of tebuconazole + carbendazim , myclobutanil + carbendazim , thiophamate-merhyl and ovraclostrobin-metiram were 92.36%,76.74%,79.8% and 78.35% respectively.更多还原