【作者】 李乖绵；

【导师】 张荣；

【作者基本信息】 西北农林科技大学 ， 植物病理学， 2007， 硕士

【摘要】 根结线虫(Metoidgyne spp. Chitwood)是一种植物根系土传定居型内寄生线虫。由于其寄主范围广,同时发生危害隐蔽、传播途径众多、繁殖效率高、抗逆力强(卵、卵囊),因此防治十分困难。目前生产上对根结线虫的控制主要依赖化学防治,而化学杀线剂大多属于高毒、高残留农药,大量使用造成地下水污染,带来人畜中毒、环境污染及生态破坏等严重问题。因而在生产中亟需安全、高效、实用的控制技术和替代药剂。Agri-Terra是由美国加州农产品有限公司(CAL AGRI PRODUCTS LLC)研制开发的一种环境友好杀线剂,具有高效、低毒、无污染等优点。本研究以陕西省发生较严重的南方根结线虫(Meloidogyne incognita)为研究对象,系统研究了Agri-Terra对南方根结线虫卵囊孵化的影响、二龄幼虫的毒杀活性及在温室、田间试验的控制效果,旨在探索新型杀线剂Agri-Terra对根结线虫的防治潜力。在离体条件下测定了Agri-Terra对南方根结线虫(Meloidogyne incognita)卵囊的抑孵作用及对二龄幼虫的毒杀活性。结果表明,Agri-Terra能明显地抑制南方根结线虫的卵囊孵化,相对抑制率最高达93.6%;对二龄幼虫具有一定的毒杀作用,其毒杀效果随着处理浓度的提高及时间的延长,也随之增强,在48 h时,二龄幼虫的的校正死亡率达98.9%。初步确定该药剂在后期的研究中,可使用的药剂浓度范围在1.0%~3.0%。在温室盆栽条件下,以番茄和黄瓜为寄主,研究了Agri-Terra对南方根结线虫的防治效果。结果表明,Agri-Terra可有效地控制番茄和黄瓜根结线虫的危害。药后90 d土壤中南方根结线虫二龄幼虫虫口减退率可达81.8﹪(番茄)/82.9﹪(黄瓜),与对照相比,防治后番茄和黄瓜的产量均有明显的增加。田间药效试验结果表明,药后90 d,二龄幼虫虫口相对减退率最高达81.6%,相对防效高达72.1%(病指由94.0%降低到26.2%),二者均显著高于对照药剂阿维菌素。同时通过Agri-Terra药剂处理90 d后对卵囊孵化的抑制作用研究表明,Agri-Terra对卵囊的抑孵作用在作物整个生长期起作用。Agri-Terra具有持效性长的特点。通过在移植前一次用药、移植前-移栽后30 d两次用药及移植前-移栽后30 d-移栽后60 d三次用药的不同用药方式试验,结果表明,三种用药方式下防效随着用药次数的增加而增加,两次用药和三次用药无显著性差异。因此我们认为两次用药方式是比较经济的防治方式。通过Agri-Terra杀线剂对植株的生理指标及对植株的生长发育影响的研究,其结果表明该药剂对植株是安全的,并有一定刺激植株生长的作用,同时Agri-Terra处理的植株不易感病(如白粉病、霜霉病、灰霉病等),因此Agri-Terra是一种较高推广应用价值的杀线剂。通过本研究初步建立了一套根结线虫药效评价体系,并且确定土壤中二龄幼虫虫口减退率、防效及产量是评价杀线剂药效的重要指标。为研究和开发根结线虫杀线剂奠定基础。更多还原

【Abstract】 The root-knot nematodes diseases were having become the common ones in vegetable field. The south root-knot nematodes(Meloidogyne incognita) were the predominant species. The hosts were distributed widely.Meanwhile it spreads by many disseminatiors, propagates very fast, and resists adversity (eggs,egg masses) stupendously. So it is very difficult to control. At present, The root-knot nematodes diseases control by chemical pesticide.Although chemical pesticide can control nematodes effectively, it brings negative effects severiously. So search substitutive medicaments and mefeasible technology urgently. Agri-Terra, developed by CAL AGRI PRODUCTS LLC, is an efficient, environmentally friendly new nematocide with low toxicity.The effects of Agri-Terra at different concentration on egg masses hatching and juvenile of Meloidgyne incognita were investigated.in laboratory. The hatching of egg masses significantly was suppessed. Mortality of the second juveniles was insignificant. A decline rate of J2 was 52.9%~93.6%. Corrected mortality was 98.9﹪after 48h. These results indicate that the selective concentration in field.Under the greenhouse environment, our laboratory chose the pathogenic cucumber and tomato root-knot nematode (Meloidogyne incognita) as a target pest to investigate, which Agri-terra’s effectiveness tests in the small plots. The results showed Agri-Terra was extremely effective against Meloidogyne incognita infection. It significantly reduced the number of second stage larvae in soil.After 60 days, the decreasing incidence rate of J2 were 81.8﹪(tomato), 82.9﹪(cucumber)respectively. In the harvest, The cumulative cucumber and tomato yields of treated were heavier than the untreated controls.Field efficiency showed that the decreasing incidence rate of was 81.6%..The control efficacy was 72.1% (Disease index reduced from 94.0 %to 26.2%). The decline rate and control efficacy were significant better than those of the control chemical, Avermectin, 23.7% and 9.5%, respectively. Meanwhile indoor studies were egg masses hatching, which the effects of Agri-Terra at different concentration after 90 days. The results showed The hatching of egg masses significantly was repressed.So we conformed Agri-Terra can control juvenile numbers and repress egg masses hatching effectively.During greenhouse trial, Security test was manipulated. Agri-Terra was observed to affect plant growth and physiological index. The results showed that these indexes had difference between treatments by Agri-terra and treatment by Avermectin. Secondly, it was no harm cucumber and tomato In greenhouse. Additionally, Agri-terra was observed to enhance plant growth. These results indicated that Agri-terra was extremely effective against Meloidogyne incognita and could be a prospective nematocide.In this test, we get the method of egg masses hatching, found the apprais efficacy methods of control root-knot nematode,and make sure that the decline rate of J2 and yields are the apprais efficacy indexes.更多还原