【作者】 张琴；

【导师】 刘勇； 黄云；

【作者基本信息】 四川农业大学 ， 植物病理学， 2012， 硕士

【摘要】 根肿病,又称根瘤病,是由芸薹根肿菌(Plasmodiophora brassicae Woron)侵染引起的一种世界性病害。该菌侵染十字花科植物后,主要危害作物的根部,致使作物根和茎吸收传导水分和养分的功能受阻,植株生长缓慢,矮化,并且不能形成正常的叶球、花球、球茎等产品器官,造成产量下降,严重时甚至绝产。田间一旦受到根肿病菌的污染,将会长期带菌,不再适宜种植十字花科作物,严重威胁十字花科植物的种植。目前生产上对根肿病的防治一般依靠化学药剂进行防治,但目前还没有能很好防治该病的药剂。本试验以筛选出能有效防治根肿病的药剂和初步探讨药剂使用技术为目的,通过室内孢子萌发试验从15种杀菌剂中筛选出能显著抑制根肿病菌休眠孢子萌发的药剂,并将部分药剂进行盆栽和大田试验,探讨药剂在室内和大田中对根肿病的防治效果；同时探讨能高效抑制孢子萌发的药剂的种子包衣剂的配方,通过一系列的筛选试验,初步筛选出种衣剂中药剂浓度和成膜剂的浓度。试验结果如下：1.将能有效抑制根肿菌休眠孢子萌发的15种药剂进行室内毒力测定试验,并根据试验结果建立毒力回归方程。试验结果表明：科佳、德劲、福帅得3种药剂对白菜根肿病菌休眠孢子萌发的抑制效果最好,三者的EC50分别为27.98mg/L.58.24mg/L和84.55mg/L。15种药剂对白菜根肿病菌休眠孢子萌发的抑制率大小顺序依次为：科佳>德劲>福帅得>五氯硝基苯>锦绣>磺菌胺>亮盾>福美双>阿克白>精甲霜·猛锌>恶霉灵>达科宁>甲基托布津>阿米西达>霜霉威盐酸盐。2.室内盆栽试验测定能有效抑制休眠孢子萌发的科佳、福帅得、德劲、五氯硝基苯和锦绣5种药剂对苗期根肿病的防治效果。结果发现：科佳和德劲对根肿病的防治效果最好,在播种前4d和幼苗3叶1心时分别进行施药,对油菜根肿病的防治效果分别为70.83%和68.18%,对白菜根肿病的防治效果分别为66.99%和68.93%；福帅得,五氯硝基苯次之,锦绣最差。在施药两次的情况下,锦绣对油菜和白菜根肿病的防治效果只有45.84%和42.72%,显著的低于其他的药剂。3.将能有效抑制根肿菌休眠孢子萌发的药剂和成膜剂进行初步的种衣剂研究,通过对室内种子萌发,96h种根长度和种芽长度的测定,初步确定药剂浓度为6.25g/L、3.125g/L和1.5625g/L,成膜剂的浓度为0.5%、1.5%和2.5%。将筛选出的药剂浓度,成膜剂浓度和不同的药剂种子比(M：M)进行正交试验,通过室内种子萌发试验和盆栽试验,初步确定种子包衣的最佳配方为2号和5号,即药剂浓度为6.25g/L.成膜剂的浓度为1.5%,药种比为1：20和药剂浓度为3.125g/L,成膜剂浓度为1.5%,药种比为1：10,两者对油菜苗期根肿病的防治效果分别为55.76%和56.24%。4.将能有效抑制休眠孢子萌发的科佳、福帅得、亮盾和锦绣4种药剂进行大田试验。试验结果表明,经科佳1500倍移栽时灌根和移栽10d第二次灌根,科佳1500倍移栽时灌根和移栽10d福帅得2000倍第二次灌根处理的油菜植株的病情指数分别为25.97和25.33,防治效果分别为41.50%和42.94%,在供试的药剂中防治效果是最好的,对油菜产量的增产率分别为28.91%和27.64%,在供试药剂中对油菜产量的增产率也是最高的,其他供试药剂的防治效果不明显。更多还原

【Abstract】 Clubroot or nodule disease caused by Plasmodiophora brassicae Woron is one of the soil-borne disease all over the world.The root of crops is mainly harmded by the bacteria when the cruciferea crops has been infected. The function with absorbing and transmitting water of root and stem is suffocated. The growth of the susceptible plant is slow, dwarf and the plant can not form normal leafy ball, flower head, corm and another products organ,leading a serious decline in output, and even no harvest. Once the soil has been infected by P. brassicae, it will have carrier bacteria for a long term and will be no longer suitable for planting cruciferae crops, threatening seriously to plant cruciferous crops. At present, the controling clubroot generally rely on chemicals agent, but there is no chemicals agent which can control well it. In order to search the chemical agent with superior traits clubroot and using technology, the pesticide with good inhibitory effect on resting spore germination are filtered out from15kinds pesticide by resting spore germination test in room. Through pot and field experiments, the ability of some reagents on controlling clubroot are discussed at indoor and fileld. At the same time, the chemical agent, the best at inhibiting germination of resting spore of P. brassicae,will be conducted initially seed coating. The concentration of pesticide and film forming agent are initial screened out through a series of screening test. The results are listed as follows:1.15kinds of fungicide with the ability on inhibite the germination of P. brassicae were conducted testing for indoor toxicity and regression equation of15fungicides were established. The test results showed that:the EC50of Segway, BAS651.F and Fluazinam were the lowest, and the inhibiting effect were the best on resting spore germination of P. brassicae on Chinese cabbage. The EC50of three chemical pesticides were respectively27.98mg/L、58.24mg/L and84.55mg/L. The precedence ordering of inhibiting capacity of15kinds drugs on resting spores germination was Segway> BAS651.F> Fluazinam> Quintozene>BacillusSubtilis>Flusulfamide>Metalaxyl-Fludioxonil>Thiram>Dimethomor-ph>Metalaxyl-Mancozeb>Hymexazol>Chlorothalonil>Thiophanate-methyl>Azoxystrobin>Propamocab Hydrochloride.2. Five kinds of pesticide with inhibited well the germination of resting spore of P. brassicae were potted for testing the effecting on controlling clubroot disease.These pesticides were Segway、BAS651.F、Fluazinam、Quintozene and B. subtilis. The results were as follow:The control efficiencies of Segway and BAS651. F against clubroot in pot experiment were best in five testing reagents.Four days before sowing and three leaves and wholehearted of seedling sprayed respectively in soil, the control efficiencies of Segway and BAS651. F against clubrtoot in pot experiment were70.83%,68.18%on oilseed rape and66.99%,68.93%on Chinese cabbage. Fluazinam and Quintozene took second place, and Bacillus subtilis was the worst in five testing reagent. In the two application cases, the control efficiencies of B. subtilis against clubroot was45.84%on rape and42.72%on Chinese cabbage in pot experiment, and significant lower than another pesticides.3. The chemical agent.which was the best at inhibiting germination of resting spore of P. brassicae. and film-forming agent were conducted preliminary study of seed coating. By measuring seed germination,root length and bud length for96hours in room, the concentration of chemical agent,were preliminary determinated, were6.25g/L,3.125g/L,1.5625g/L, and the concentration of film forming agent were0.5%,1.5%,2.5%. The orthogonal test was conducted with the concentrations of pesticide and film forming agent which were selected out and different reagent seed ratio(M:M). Through indoor germination experiment and pot experiment.the best formula of seed coating which were determined preliminarily were the No.2and No.5, that the concentration of fungicide was6.25g/L, the concentration of film forming agent was1.5%. pharmacopoeia ratio was1:20, and the concentration of fungicide was3.125g/L,the concentration of film forming agent was1.5%, pharmacopoeia ratio wasl:10.The control efficiencies of two methods against clubroot in pot experiment were55.76%and56.24%.4. The field experiment was carried out with Segway、Fluazinam、B. subtilis and Flusulfamide which could inhibit the germination of the dormant spore. The test results showed that:Segway with diute1500times irrigated the root of the rape at transplanting and10d after transplanting,and the concentration of Segway irrigated the root at transplanting and Fluazinam with diute2000times irrigated the root at10d after transplanting were the best in these treatments. The disease index of rapeseed plant were25.97and25.33, and the controlling effect were41.50%and42.94%by two treatments.In two treatments, the increasing ration of the yield of rape seed were respectively28.91%and27.64%, and the control efficiencies of another tested drugs was not obvious.更多还原