【作者】 乔慧；

【导师】 刘芳； 傅强；

【作者基本信息】 扬州大学 ， 农业昆虫与害虫防治， 2008， 硕士

【摘要】 灰飞虱传播的水稻条纹叶枯病近年来在江淮稻区大发生,导致了水稻大面积减产甚至绝收。为探明灰飞虱的发生规律及其对不同寄主植物的适应性情况,系统调查了田间不同生境中灰飞虱种群动态,研究了不同寄植物对灰飞虱的适合度及解毒酶和靶标酶在灰飞虱寄主适应中的作用。主要结果如下:1.通过大田不同生境中灰飞虱的调查,明确了浙江富阳市灰飞虱的年发生世代及消长动态。灰飞虱在浙江富阳田间1年发生6代。小麦和杂草为主要越冬寄主植物。越冬代若虫于2月下旬～4月中上旬羽化。第1代若虫于4月中旬～5月上旬孵化,主要为害小麦。第2代若虫发生于5月下旬～6月下旬,主要分布于早稻、中稻上,由小麦及杂草上迁移而来,于6月中旬出现虫量高峰。第3代发生于在7月初至8月上旬,主要见于中稻、直播晚稻及生长茂盛的禾本科杂草地(如闲置稻田稗草)。第4代发生在8月上旬至9月上旬,主要在晚稻及闲置稻田稗草等生境,田边杂草上数量很少。第5代发生于9月上旬,主要分布于中稻、晚稻、闲置田和田边杂草地。第3、4、5代峰期分别在7月中旬、8月上旬,9月中旬。第5代成虫除杂草地上的仍可能留在原地之外,稻田中多数成虫转移到周边的麦地或杂草上,继续繁殖第6代(越冬代)。全年灰飞虱成虫有3次迁移过程。2006～2007年,富阳麦田虫量在14.9～22.7头/10m~2,稻田虫量在6.6～55头/10m~2。可见,麦田及稻田灰飞虱发生量比条纹叶枯病大发生地区少。2.通过室内笼罩饲养方法观察了水稻、玉米、高粱、稗草等57种供试植物上灰飞虱的生长发育繁殖情况。结果表明:不同供试植物上灰飞虱羽化率、若虫历期、初羽化成虫重量、成虫寿命、产卵量等参数均存在不同程度的差异。结合主成分分析和种群趋势指数分析,发现57种供试植物中,适宜灰飞虱生存的寄主植物有稗草等5种供试植物,其上灰飞虱羽化率介于59.4% -86.9%,种群趋势指数在27.8以上;较适宜灰飞虱生存的寄主植物有黑麦草等9种供试植物,灰飞虱羽化率在27.0% -64.5%之间,种群趋势指数多在10以上;较不适宜灰飞虱生存的寄主植物有牛筋草等5种供试植物,羽化率介于13.0% -35.6%,种群趋势指数在1-10之间;不适宜灰飞虱生存的植物有无芒雀麦等13种植物,羽化率在10%以下,种群趋势指数在1以下;玉米等25种植物上灰飞虱若虫则不能羽化为成虫。其中黑麦草、棒头草、菵草、白顶早熟禾、野燕麦、荠菜等为新证实寄主植物。3.以褐飞虱为对照,测定了灰飞虱在经历水稻与稗草转换后,体内解毒酶(羧酸酯酶和谷胱甘肽S-转移酶)和靶标酶(乙酰胆碱酯酶)的活力,以明确解毒酶和靶标酶在灰飞虱寄主适应中的作用。结果表明:两种飞虱取食稗草后,体内的解毒酶比活力存在着显著差异。取食稗草后,灰飞虱体内的α-羧酸酯酶比活力显著高于褐飞虱的;与褐飞虱相比,有更多灰飞虱个体的酶比活力分布于高酶比活力区域。取食稗草后,灰飞虱雄虫体内β-羧酸酯酶比活力及雌虫体内的谷胱甘肽S-转移酶比活力显著高于褐飞虱的;但两种飞虱的β-羧酸酯酶及谷胱甘肽S-转移酶比活力频率分布存在较广范围的重叠区域。取食稗草后,两种飞虱体内的乙酰胆碱酯酶比活力无显著差异。因此,灰飞虱体内的解毒酶尤其是α-羧酸酯酶在其寄主适应中起着重要的作用。更多还原

【Abstract】 Rice stripe disease, caused by Rice stripe virus (RSV), led to severe or even crippling losses in JiangHuai rice region in recent years. As the most important vector of RSV, the small brown planthopper (SBPH) (Laodelphax striatellus) is largely responsible for the epidemic phase of the disease. In order to clarify the occurrence regularity and host adaptation of SBPH, the population dynamic of SBPH in different habitats, the fitness of SBPH on different plants and the effect of detoxifying enzymes and target enzymes on host adaptation of SBPH were studied in this paper. The main results were as followings:1. The population dynamic of SBPH in different habitats was investigated. The results showed that SBPH occurred six generations a year and overwintered mainly on wheat and weeds in Fuyang county, Zhejiang province. The overwintering generation adults emerged from late February to middle April. The first generation nymphs hatched from middle April to early May, and mainly damaged wheat. The second generation nymph occurred from late May to late June and mainly infested the early rice and Mid-rice. The peak of this generation appeared in the middle June. The third generation occurred from early July to early August, mainly infested Mid-rice, direct seeding late rice and the Gramineous weeds of idle field(e.g. Echinochloa crusgalli of wild land). The fourth generation occurred from early August to early September, mainly damaged late rice, and a few pests were observed on weeds. The fifth generation occurred in early September, mainly distributed in Mid-rice, late rice, idle field and weeds land. The fastigium of the third, fourth and fifth generation took place in middle July, early August and mid September respectively. The fifth generation adults in the paddy field immigrated to the wheat yard and weeds, but the adult in the weeds yard did not immigrate and went on developing. The adult of SBPH could immigrate three times in whole year. The number of SBPH was 14.9 to 22.7 individuals/10m~2 in wheat yield and 6.6～55 individuals/10m~2 in rice yield respectively in 2006～2007. The average quantity of SBPH in Fuyang was lower than that in the heavy disaster areas of rice stripe disease.2. The development and reproduction of SBPH on 57 different plants including Oryza sativa, Zea mays, Sorghum vulgare and E. crusgalli etc were studied by caging method in laboratory. The results indicated that nymphal development duration, emergence rate, adult weight, adult longevity and fecundity of SBPH on different plants were significantly different. According to principal component analysis and population trend index analysis, five plants (E. crusgalli etc.) were the most suitable host plants, with the emergence rates of SBPH on these plants ranging from 59.4% to 86.9%, and the population trend indexes above 27.8. Nine plants (Lolium perenne etc.) were also suitable for the small brown planthopper, 27.0% - 64.5% individuals on those plants can emerge, and the population trend indexes were above 10. Five plants such as Eleusine indica were scarcely suitable for the survival of SBPH, 13.0% - 35.6% emergence rates were observed, and population trend index were 1-10. Thirteen plants (Bromus inermi etc.) were unfit for SBPH’s survival, less than 10% individuals on them can emerge, and the population increase could not reach 1. Nymphs of SBPH on the other twenty-five plants such as Zea mays could not emerge. Lolium maloiforam, Beckmannia syzigachne, Polypogon fugax, Poa acroleuca, Avena fatua and Capsella bursapastoris were the newly confirmed host plants.3. The activity of detoxifying enzymes and target enzymes in SBPH, compared with BPH, which fed on E. crusgalli but firstly on rice, were measured to study the effect of those enzymes on the host adaptation of the pest. The results indicated that the activities of detoxifying enzymes in SBPH were significantly different from those in BPH. Theα-NA esterase activity in SBPH was significantly higher than that in BPH, and there were more SBPH individuals having highα-NA esterase activity. Theβ-NA esterase activity in male of SBPH and glutathione S-transferase activity in female of SBPH were apparently higher than those in BPH, but the distribution of the enzyme activity in both planthoppers seriously overlapped. Few differences were observed in acetylcholinesterase activity testing. The results indicated that carbaxylesterase especiallyα-NA esterase played an important role in host adapting in SBPH.更多还原