【作者】 卢海燕；

【导师】 祝树德；

【作者基本信息】 扬州大学 ， 农业昆虫与害虫防治， 2010， 博士

【摘要】 本文以农药-水稻-害虫(褐飞虱、稻纵卷叶螟)-天敌(稻虱缨小蜂、黑肩绿盲蝽、拟水狼蛛)为研究系统,研究了4种稻田常用农药对水稻植株挥发物释放的影响及其生态效应。结果如下:1)研究了新烟碱类杀虫剂吡虫啉、植物源杀虫剂印楝素、有机磷杀虫剂三唑磷以及激素型除草剂二甲四氯钠对稻株挥发物释放的影响。利用固相微萃取法(SPME)捕集水稻挥发物,并用气相色谱和质谱联用(GC-MS)对其进行分离和鉴定。吡虫啉处理的褐飞虱为害稻株中共捕集到挥发物组分40种,其中已定性的25种,包括萜烯类(16种)、醇类(3种)、烷烃类(3种)、酮类(1种)、酯类(1种)以及萘(1种);印楝素处理的褐飞虱为害稻株挥发物组分共25种,其中已定性的14种,包括萜烯类(8种)、醇类(3种)、烷烃类(2种)以及酯类(1种);三唑磷处理的稻纵卷叶螟为害稻株挥发物组分共36种,其中已定性的15种,包括萜烯类(8种)、醇类(3种)、烷烃类(2种)、酯类(1种)以及酮类(1种);二甲四氯钠处理的健康稻株中共捕集到挥发物组分24种,其中已定性的8种,包括萜烯类(6种)、醇类(1种)以及烷烃类(1种)。已定性的组分中,(-)-异喇叭烯、(-)-α-雪松烯、(+)-β-雪松烯、罗汉柏烯、依兰油烯、2,4a,5,6,7,8,9,9a-八氢-3,5,5-三甲基-9-亚甲基-1H-苯并环庚烯、1(10),4-杜松二烯、3,9-杜松二烯、1,2,3,4,6,8a-六氢-1-异丙基-4,7-二甲基萘、雪松烯、2,6,10-三甲基十四烷等11种组分为新报道的水稻挥发物组分。无论是农药处理的稻株挥发物还是对照植株(清水处理)挥发物,均以倍半萜类化合物的种类数和相对含量最高。与未施药稻株释放的挥发物相比,药剂处理稻株挥发物中均未有新组分产生,但部分组分的相对含量发生了变化。吡虫啉的浓度(未施药、低浓度、高浓度)、施药天数(1d、3d、5d、7d)及与其他生物因子(水稻品种、褐飞虱为害密度)的互作分别导致20%、85%、90%的组分相对含量显著改变,印楝素的对应作用分别为88.0%、76.0%、96.0%,三唑磷的对应作用分别为13.9%、75.0%、88.9%,二甲四氯钠的对应作用分别为54.2%、45.8%、75%。上述结果表明,印楝素对水稻挥发物释放的影响最大,吡虫啉和三唑磷次之,二甲四氯钠最小,这可能与农药特性以及不同的作用方式有关。不同农药处理的水稻植株挥发物中,水杨酸甲酯、(-)-异喇叭烯、(-)-α-可巴烯、(-)-α-雪松烯、(+)-β-雪松烯、(-)-异石竹烯、(-)-姜烯、雪松醇、正十七烷等9种组分的相对含量常发生变化,说明这些挥发物组分的释放不稳定,较易受农药因子干扰。挥发物组分多样的生物合成途径使其受农药影响的程度各异。2)研究了吡虫啉处理稻株的挥发物在稻虱缨小蜂和黑肩绿盲蝽寄主选择行为中的作用。稻虱缨小蜂行为生测采用“Y”型嗅觉仪,黑肩绿盲蝽采用“H”型嗅觉仪。2种天敌均对不同浓度吡虫啉处理稻株的挥发物作出选择。当褐飞虱的密度为10头/稻苗时,与高浓度(37.50 g a.i / hm2)吡虫啉处理稻株挥发物相比,稻虱缨小蜂明显地选择了低浓度(15.00 g a.i /hm2)处理稻株(药后5天除外)。黑肩绿盲蝽对吡虫啉处理稻株挥发物的喜好则表现为未施药稻株>低浓度稻株>高浓度稻株。吡虫啉不同浓度处理后相对含量存在变化的稻株挥发物组分,如水杨酸甲酯、(-)-姜烯、正十六烷等,对稻虱缨小蜂和黑肩绿盲蝽的引诱或驱避作用可能是导致其寄主选择行为的一个原因。不同的施药天数亦影响天敌对吡虫啉处理稻株挥发物的选择性。褐飞虱密度为2头/稻苗时,以低浓度(或高浓度)吡虫啉喷施水稻植株,与施药7d的稻株相比,稻虱缨小蜂明显地选择了施药3d、5d(或1d、5d)的稻株。褐飞虱密度为10头/稻苗时,与高浓度吡虫啉处理1d的稻株相比,稻虱缨小蜂明显地选择了施药3d的稻株。与药后3d、5d、7d的稻株挥发物相比,黑肩绿盲蝽更多地趋向施药1d的稻株挥发物。稻虱缨小蜂和黑肩绿盲蝽均避开药后天数较长的稻株,说明吡虫啉药后7d的稻株挥发物对天敌有驱避作用。3)研究了印楝素处理稻株的挥发物在稻虱缨小蜂和拟水狼蛛寄主选择行为中的作用。2种天敌的行为生测均采用“Y”型嗅觉仪。结果表明,当褐飞虱的密度为2头/稻苗时,稻虱缨小蜂和拟水狼蛛对所有成对气味源(低浓度处理稻株与未施药稻株、高浓度处理稻株与未施药稻株、低浓度处理稻株与高浓度处理稻株)未表现出明显的选择性。只有当褐飞虱密度为10头/稻苗时,天敌的选择行为才出现显著差异。与未施药稻株挥发物相比,稻虱缨小蜂明显趋向于高浓度(2.25 L/ hm2)处理(施药1d)稻株挥发物。与高浓度处理(施药1d、3d)的稻株挥发物相比,稻虱缨小蜂明显地喜好低浓度(1.13 L/ hm2)处理稻株挥发物。印楝素处理的水稻植株挥发物对拟水狼蛛的寄主选择行为影响较小。与未施药的稻株挥发物相比,拟水狼蛛明显地趋向高浓度处理(施药3d)的稻株挥发物。施用印楝素的稻株挥发物较未施药稻株更吸引天敌,说明植物源农药对天敌较为安全,有利于更大程度地发挥天敌的生物控制作用。因此,可以通过调整农药的使用,使农药与水稻挥发物协同发挥作用,促进水稻害虫的可持续治理。4)测定了农药处理后相对含量较高或改变较大的14种水稻挥发物组分对褐飞虱3种天敌的生物活性。稻虱缨小蜂行为生测采用“Y”型嗅觉仪,黑肩绿盲蝽和拟水狼蛛均采用“H”型嗅觉仪。结果表明,在一定的浓度及观察时间下,对黑肩绿盲蝽起作用的组分是芳樟醇(引诱)、水杨酸甲酯(引诱)、(-)-异喇叭烯(引诱)、(-)-异石竹烯(引诱)、柠檬烯(驱避)、橙花叔醇(驱避)、雪松醇(驱避)等7种,对拟水狼蛛存在生物活性的是水杨酸甲酯(引诱)、(-)-异石竹烯(引诱)、法尼烯(引诱)、橙花叔醇(引诱)、(-)-α-可巴烯(驱避)、正十六烷(驱避)、雪松醇(驱避)等7种,能引起稻虱缨小蜂反应的组分是柠檬烯(驱避)、(-)-异喇叭烯(引诱)2种。其中,黑肩绿盲蝽和拟水狼蛛的共同活性组分是水杨酸甲酯、(-)-异石竹烯、橙花叔醇和雪松醇,除橙花叔醇外作用一致;黑肩绿盲蝽和稻虱缨小蜂的共同活性组分是柠檬烯和(-)-异喇叭烯,且作用一致;拟水狼蛛和稻虱缨小蜂无共同的活性组分。测定的14种组分中,(-)-α-雪松烯、(+)-β-雪松烯、(-)-姜烯和正十七烷等4种组分对3种天敌均无生物活性。生产上可以利用能引诱天敌的挥发物组分,加强天敌对害虫的控制作用。5)测定了14种水稻挥发物组分对褐飞虱的生物活性。行为生测(采用“H”型嗅觉仪)中,在一定的浓度及观察时间下,对褐飞虱表现出引诱作用的是柠檬烯、(-)-异喇叭烯、(-)-异石竹烯、法尼烯和雪松醇等5种组分,表现为驱避作用的是芳樟醇、水杨酸甲酯、(-)-α-可巴烯、(-)-α-雪松烯、(+)-β-雪松烯、(-)-异石竹烯、法尼烯和橙花叔醇等8种。值得注意的是,(-)-异石竹烯和法尼烯在不同的浓度下表现出相反的作用。(-)-姜烯、正十六烷和正十七烷等3种组分对褐飞虱无生物活性。触角电位测定(采用EAG反应仪)结果表明,褐飞虱对大部分的倍半萜烯类反应值较大(法尼烯和姜烯除外),其次是单萜及萜类含氧衍生物,对烷烃类化合物反应值较小或者不反应。其中,对(-)-异喇叭烯、(-)-异石竹烯和(-)-α-可巴烯的反应值最大,对(-)-姜烯和正十七烷几乎没有反应,这与褐飞虱的行为反应结果基本一致。以上结果表明,农药处理的稻株挥发物在褐飞虱寻找寄主的过程中起着重要的作用,但挥发物各组分所起的作用存在差异。更多还原

【Abstract】 The influence of pesticides on rice plant volatiles and its ecological effects were investigated in a system involving pesticides, rice, pests (brown planthopper (BPH), Nilaparvata lugens St?l and the rice leaf folder (RLF), Cnaphalocrocis medinalis Guenee) and their natural enemies (an egg parasitoid, Anagrus nilaparvatae Pang et Wang, a predatory bug, Cyrtorhinus lividipennis Reuter and a predatory spider, Pirata subpiraticus Boes.et str.). The results are as follows:1) Volatiles of rice plants treated with 4 pesticides, including imidacloprid (new neonicotinoid insecticide), azadirachtin (botanical insecticide), triazophos (organophosphorus insecticide), MCPA-Na (hormone herbicide), were collected by solid phase microextraction (SPME) and then identified by gas chromatography coupled with mass spectrometry (GC-MS). Forty components were collected from headspace of rice plants infested by BPH under imidacloprid application, 25 of which were identified, including terpenes (16 kinds), alcohols (3 kinds), alkanes (3 kinds), ketones (1 kind), acetates (1 kind) and naphthalene (1 kind); Twenty-five components were collected from headspace of rice plants infested by BPH under azadirachtin application, 14 of which were identified, including terpenes (8 kinds), alcohols (3 kinds), alkanes (2 kinds) and acetates (1 kind); Thirty-six components were collected from headspace of rice plants infested by RLF under triazophos application, 15 of which were identified, including terpenes (8 kinds), alcohols (3 kinds), alkanes (2 kinds), acetates (1 kind) and ketones (1 kind); Twenty-four components were collected from headspace of healthy rice plants under MCPA-Na application, 8 of which were identified, including terpenes (6 kinds), alcohols (1 kind) and alkanes (1 kind). Eleven of the identified components were newly found in rice plants, including (-)-isoledene、(-)-α-cedrene、(+)-β-cedrene、thujopsene、cadina-1(10),4-diene、cadina-3,9-diene、2,4a,5,6,7,8,9,9 a-octahydro- 3,5,5-trimethyl-9-methylene-1H-benzocycloheptene、cedrene、muurolene、1,2,3,4,6,8 a-hexahydro-1-methylethyl-4,7-dimethyl-naphthalene and 2,6,10-trimethyl-tetradecane.Both kinds and proportions (percent of total peak area) of the sesquiterpenes were the highest in all treatments (pesticides treated or not). Compared with the CK (water treated plants), the treatments of pesticides did not result in the emission of new compounds, but rather the relative proportions among the compounds in the blend were altered. The proportions of 20% components had significant differences under imidacloprid application at three levels. The proportions of 85% components changed at different days after imidacloprid treatment. Furthermore, the proportions of 90% components were significantly changed due to the interactions between imidacloprid and other factors. The corresponding values of azadirachtin were 88.0%、76.0%、96.0%, triazophos were 13.9%、75.0%、88.9% and MCPA-Na were 54.2%、45.8%、75%, respectively. Therefore, the effect of pesticide on rice volatiles (ordered from high to low) were azadirachtin > imidacloprid > triazophos > MCPA-Na. The botanical insecticide azadirachtin was most effective which maybe have relation with its action mode. Among the changed components, methyl salicylate, (-)-isoledene, (-)-α-copaene, (-)-α-cedrene, (+)-β-cedrene, (-)-isocaryophyllene, (-)-zingiberene, cedrol, n-heptadecane were much easier to be influenced by pesticides treatment. The various biosynthesis pathways were responsible for the different changing trends of volatile components.2) Orientation responses of A. nilaparvatae (using Y-tube olfactometer) and C. lividipennis (using H-tube olfactometer) to rice plants treated by imidaclopid were conducted. The results showed that volatiles emitted from rice plants treated by imidacloprid with 3 concentrations had significant effects on the orientation responses of A. nilaparvatae and C. lividipennis. When the density of BPH was 10 females per plant, a majority of the parasitoid were attracted to rice plants treated with low concentration (15.00 g a.i /hm2) of imidacloprid, but not to high concentration (37.50 g a.i / hm2) ones, except at 5 days after treatment (DAT). The attractions of rice plants to the bug were water treated ones (CK) > low concentration treated ones > high concentration treated ones. Volatiles emitted from rice plants at different days after imidacloprid treatment also had significant effects on host searching behaviors of A. nilaparvatae and C. lividipennis. When BPH density was 2 females per plant, the parasitoid exhibited greater preference to rice plant volatiles from 1DAT, 3DAT, 5DAT than those from 7 DAT. When the damage density was 10 females per plant, the parasitoid preferred rice plant volatiles from 3 DAT under high imidacloprid application than those from 1 DAT. The bug preferred volatiles emitted from rice plants at 1DAT than those from 3DAT, 5DAT, 7DAT. The effects (attraction or repellent) of the components changed after imidacloprid treatment, such as methyl salicylate, (-)-isoledene, (-)-α-copaene, (-)-zingiberene, n-heptadecane, thujopsene, n-hexadecane, on the natural enemies maybe one reason of their orientation responses.3) Orientation responses of A. nilaparvatae and P. subpiraticus to rice plants treated by azadirachtin at three levels were studied with Y-tube olfactometer. The results indicated that when the BPH density was 2 females per plant, volatiles emitted from rice plants treated by azadirachtin with different concentrations had no effect on the orientation behaviors of the natural enemies. Only when the BPH density was 10 females per plant, host searching behaviors of natural enemies had significant differences. The parasitoid oriented significantly towards the odours emitted from rice plants under high (2.25 L/hm2) azadirachtin application at 1 DAT compared with water treated ones (CK). When compared with rice plants under high azadirachtin application, the parasitoid preferred volatiles from low (1.13 L/hm2) azadirachtin treated ones at 1 DAT and 3 DAT. The behavioral responses of P. subpiraticus to rice plants under azadirachtin application had no significant difference except at 3 DAT between high azadirachtin application plants and the CK plants. The rice plants under azadirachtin application were more attractive to the natural enemies than CK plants, which indicated that the botanical insecticide azadirachtin was safe to natural enemies and was helpful to improve their natural control effect on the pests. And thus, the mediations of pesticide applications should be taken to make full use of the synergism of pesticide and plant volatiles in sustainable management of rice pests.4) The biological activities of 14 rice volatile components to 3 natural enemies of BPH were measured in Y-tube olfactometer or H-tube olfactometer. The results demonstrated that under specific concentrations of volatile compounds and hours after releasing insects, the bug could be obviously attracted by linalool, methyl salicylate, (-)-isoledene, (-)-isocaryophyllene and repelled by linalool, nerolidol, cedrol. The spider could be attracted by methyl salicylate, (-)-isocaryophyllene, trans-β-farnesene, nerolidol, and repelled by (-)-α-copaene, n-hexadecane and cedrol. The wasps were attracted by (-)-isoledene and repelled by limonene. methyl salicylate, (-)-isocaryophyllene and cedrol had the same effects on behavioral responses of the bug and the spider, and limonene, (-)-isoledene were common active components of the bug and the parasitoid, while there was no common active compound between the spider and the parasitoid. Among the 14 compounds tested, (-)-α-cedrene, (+)-β-cedrene, (-)-zingiberene and n-heptadecane had no biological activity to all 3 natural enemies. The volatile components that attractting the natural enemies could be used in field to enhance the control of the natural enemies to the pests.5) The biological activities of 14 rice volatile components to BPH were studied. H-tube olfactory test showed that under specific concentrations of volatile compounds and hours after releasing insects, BPH could be obviously attracted by limonene, (-)-isoledene, (-)-isocaryophyllene, trans-β- farnesene and cedrol, and repelled by linalool, methyl salicylate, (-)-α-copaene, (-)-α-cedrene, (+)-β-cedrene, (-)-isocaryophyllene, trans-β-farnesene and nerolidol. The issue needing attention was (-)-isocaryophyllene and trans-β-farnesene had opposite influence to BPH at different concentrations. (-)-zingiberene, n-hexadecane and n-heptadecane showed no biological activity to BPH. In electrophysiological responses test, most of the sesquiterpenes (except trans-β-farnesene and (-)-zingiberene) elicited strong responses, and monoterpenoids and terpene oxides elicited moderate responses, while alkanes elicited the lowest or no responses. The EAG responses of BPH to (-)-isoledene, (-)-isocaryophyllene and (-)-α-copaene were the highest, and (-)-zingiberene, n-heptadecane were the lowest, which were almost consistent with the behavioral responses. The results suggested that volatiles from rice plants after pesticide treatment played a vital role in their host-finding behavior, however, each component played on different role.更多还原