【作者】 赵晴；

【导师】 秦玉川；

【作者基本信息】 中国农业大学 ， 农业昆虫与害虫防治， 2014， 博士

【摘要】 自从20世纪90年代烟粉虱Bemisia tabaci (Gennadius) B生物型的成功入侵以来,烟粉虱在我国多地暴发,造成了严重的经济损失。目前Q型已逐渐取代B型,发展成我国蔬菜、花卉等经济作物上的重要生物型。研究表明,烟粉虱寄主植物多达74科600余种,但在每种寄主植物上的发生危害不尽相同,其嗜好的寄主主要有黄瓜、番茄、甘蓝、棉花、烟草等,但仍然有许多烟粉虱的弱选择性寄主植物,它们可能对烟粉虱具驱避作用。通过应用烟粉虱的弱选择性寄主植物来进行烟粉虱的防治,也鲜有报道。因此,开展该方面的研究,可以为开发高效的烟粉虱驱避剂提供理论依据,并为烟粉虱的防治提供新的思路和途径。作者于2010-2012年,分别在北京和河北涿州,选取了5种烟粉虱的弱选择性伴生蔬菜(包括芹菜、莴笋、木耳菜、苋菜、空心菜),利用Y型嗅觉仪检测了其对烟粉虱B、Q两生物型行为的影响；通过田间间作实验,验证了这5种寄主蔬菜对减少黄瓜上烟粉虱虫口数量的作用;并利用顶空固相微萃取-气质联用技术,探索了对烟粉虱具有较好驱避作用的芹菜和木耳菜的挥发性化学组份,从中筛选出了两个驱避性成份,进行了室内的行为测定,验证了其对烟粉虱B、Q两种生物型的活性。另外,本研究还利用分子生物学的技术手段,检验了B型烟粉虱的一个化学感受蛋白CSP的基因,与已登录的Q型烟粉虱化感蛋白BtabCSP完全一致,并探讨了该基因在B型烟粉虱不同龄期和部位的时空表达。主要研究结果如下：(1)通过室内Y型嗅觉仪的检测,B、Q两型烟粉虱对其弱选择性寄主的研磨汁液的反应率和选择率,均低于对其适宜性寄主黄瓜的汁液的反应率和选择率；两种生物型对五种弱选择性寄主蔬菜的相对选择率显著低于对黄瓜的相对选择率,说明这5种蔬菜均对烟粉虱有一定的驱避性。B、Q两种生物型对5种蔬菜研磨汁液的行为反应存在差异。(2)露地黄瓜与这5种弱选择性蔬菜进行的间作伴生实验表明,各间作处理后黄瓜上的烟粉虱平均虫口数量显著低于对照(黄瓜单作)；在温室进行的类似间作实验,其结果和露地间作相一致,5种弱选择性蔬菜中芹菜和木耳菜效果最好,与这两种蔬菜间作的黄瓜上烟粉虱虫口数量显著低于其它处理和对照。(3)顶空固相微萃取-气谱质谱联用测定结果表明,黄瓜、芹菜、木耳菜的挥发物种类包括脂肪酸、萜类、芳香族、烃类四大类,黄瓜的挥发物中主要含有烷烃类物质和脂肪酸及其衍生物类,芹菜的挥发物主要为萜类物质占90%以上,木耳菜的挥发物种主要含有萜类和烷烃类物质。其中芹菜中的D-Limonene和木耳菜中的Geranyl nitrile是其最主要的挥发物。(4)Y型嗅觉仪活性检测表明,两种生物型烟粉虱对D-Limonene、Limonene和Geranyl nitrile三种化学纯品的反应率和选择率均比对照低。测试结果表明芹菜中的D-limonene和木耳菜中的geranyl nitrile是两种蔬菜对烟粉虱起到驱避效果的化学物质；发现B、Q两生物型对这些气味物质的选择行为存在差异。(5)利用RNA提取、反转录合成cDNA等技术克隆得到了B型烟粉虱CSP基因(BtabCSP),通过序列分析,与已登录的Q型烟粉虱GenBank中序列号为GU250808的基因完全一致,说明烟粉虱的这两种生物型在这个化感蛋白基因上没有差别。更多还原

【Abstract】 After the successful invasion since90s20century, the whitefly Bemisia tabaci (Gennadius) of biotype B has broke out and caused serious economic loss in many places in China. Now biotype Q which replaced the biotype B has developed to be one of the most important pests of agriculture and horticulture. B. tabaci has been recorded from more than600plant species of74families. It has different preference for whiteflies to select different host plants, and its’ frefered host plants were cucumber, tomato, cabbage, cotton, tabacco, etc; nevertheless, there are still many less prefered host plants for whiteflies, some of them may possess a repellent effect against the whiteflies. It has rarely reported that the whiteflies controlled by utilizing less prefered host plants. So the research on the less prefered hosts could provide theoretical basis for developing efficient repellent, new ideas and approaches for controlling the whitefly. From2010to2012, in Beijing and Zhuozhou of Hebei, there are five less prefered vegetables including celery (Apium graveolens), asparagus lettuce (Lactuca psativap L. var. asparaginap Bailey), malabar spinach (Gynura cusimbua (D.Don) S. Moore), edible amaranth (Amaranhus mangostanus L.), water spinach (Ipomoea aquatica Forsk.), were selected to do the research in laboratory and field respectively. For probing the bio-chemical relationship between the whiteflies and their host vegetables, their preferred and less prefered vegetables and some of their volatiles were tested by Y-tube olfactometer bioassay and HS-SPME-GC\MS. The field intercropping experiment has verified the roles of the5kinds of host vegetables on lowing the density of whitefly on cucumber. At last, the recombinant CSP gene of B biotype was obtained by methods of molecular biology, and the expression of different instars and parts of whiteflies biotype B were investigated. The following is the main results:(1) By the Y-tube olfactometer bioassay, the response rate and selected rate of both biotype whiteflies to the five less prefered vegetable extracts were lower than that from cucumber. And the relative selected rates of both biotypes to the five less prefered extracts were significantly lower than cucumber. There is a repellent effect against the whitefly from the five vegetables. Whereas, there showed a different select behavior to the five vegetables between the two biotypes of the whitefly.(2) In the open field, population densities of whiteflies on the cucumber intercropped with either one of five less prefered vegetables were significantly lower than those of monoculture cucumbers; Similar trend of the whitefly population was also found from those experiments carried-out in the green houses, but only with significant decreases observed from cucumber intercropped with celery and malabar spinach.(3) The result of HS-SPME-GC\MS showed the volatile profiles from celery, malabar spinach and cucumber consisted of four major groups of compounds, fatty acids, terpenes, aromatics and hydrocarbons, as well as their derivatives. In cucumber plants, hydrocarbons were the dominant group of chemicals identified, followed by aromatics and fatty acids. For celery, terpenoids and their derivates were the major constituents with more than90%compounds identified. Terpenoids and hydrocarbons were found also higher in malabar spinach. D-limonene was dominant in celery and Geranyl nitrile was the main volatile in malabar spinach.(4) In the validation test by Y-tube olfactometer between the main volatile components from the less prefered vegetables and their identical chemicals, the two biotype whitefly adults had a lower action and selectance to Limonene, D-Limonene and geranyl nitrile. The results mean that D-Limonene from cellery and geranyl nitrile from malabar spinach are the volatile chemicals to repel the whitefly. It exists difference between the biotype B and Q for their selectance to some volatiles.(5) By the biotech of RNA extraction and RT-PCR cloning cDNA etc, a CSP gene was cloned from B. tabaci biotype B after the sequence analysis. The gene was completely coincidence with that BtabCSP (GU250808) from biotype Q.更多还原