芜菁夜蛾线虫对小木蠹蛾侵染能力的研究

1988年室内试验结果证明:芜菁夜蛾线虫的5个品系Agriotos、All、Mexican、NC 116、Florida对蛀干害虫小木蠹蛾幼虫有很高的侵染力;但不侵染蛹。用Agriotos品系作试验,剂量和温度影响小木蠹蛾的死亡率和致死速度。当剂量大于25条线虫/木蠹蛾幼虫时,死亡率可达92％以上,同一剂量对一年、二年生幼虫的死亡率差异不显著。在15-30℃的范围内,线虫均能侵染和杀死寄主,但30℃不能在寄主尸体内繁殖。25℃为线虫浸染的最适宜温度,寄主死亡率最高,死亡速度也最快。一头5龄和7龄木蠹蛾幼虫能繁殖侵染期线虫16万和48万头。在10℃低温中,线虫不能侵染寄主,但并不死亡,当移入适宜的温度后,能迅速恢复活动。在35℃高温中,线虫则很快死亡。     

感染松材线虫病松树滑刃目线虫调查

 本研究首次在全国范围内调查感染松材线虫病松树体内滑刃目线虫的种群组成,包括种类记述和数量组成分析。结果表明:在300份样品中共分离得到10种滑刃目线虫,隶属于3科、4属,其中有2个国内新记录种;它们是松材线虫、拟松材线虫、霍夫曼尼伞滑刃线虫、薄荷滑刃线虫、大核滑刃线虫、小麦长尾线虫(国内新记录种)、爱尔密那长尾线虫(国内新记录种)、李氏长尾线虫、吴氏长尾线虫和外滑刃科线虫一种;描述并且图示比较它们的形态特征。种群数量组成分析表明:松材线虫在感病松树体内占据绝对的优势,削弱了松树线虫群落组成的多样性,即线虫群落结构趋向单一化。研究还表明,利用长尾属线虫的捕食习性来控制中国松材线虫病的流行与危害值得进一步探索与研究。     

Sampling Survey and Identification of Races of Soybean Cyst Nematode (Heterodera glycines Ichinohe) in Huang-Huai Valleys

Soybean cyst nematode (SCN Heterodera glycines Ichinohe) is one of the most important nationwide soybean diseases in China. A total of 38 soil specimens or locations in the area was sampled and tested for SCN races during 2001-2003 for the inspection of race distribution in Huang-Huai Valleys. A map of race distribution was constructed according to the data from both the present study and the published reports cited. Three areas, namely, the area of southeast to Jinan in Shangdong Province; the area of northern Henan Province and its border region to south of Hebei Province; and the area of Luohe, Zhoukou of Henan Province and Fuyang of Anhui Province mainly infested with Race 1 were identified. Race 4 was predominant in Shanxi Province, Beijing and the adjacent area of Henan, Shandong, and Anhui provinces, and the delta of Huanghe River in Shandong Province. Race 2 was mainly found in Liaocheng, Dezhou of Shangdong Province and Shijiazhuang of Hebei Province, and Jiaozuo and Huojia of Henan Province. Race 7 was distributed in the west part of Jiaodong Peninsula of Shandong Province and Kaifeng, Huaxian, Wenxian of Henan Province. Race 5 was found and scattered in Hebei and Henan Province. Race 9 was found in Shangqiu of Henan Province, which was reported for the first time in China. It can be seen that Race 1 and Race 4 were the two predominant races in Huang-Huai Valleys, and that research should focus on developing resistant cultivars of these races. There might exist other races in an area with some predominant races. The race substitution in the past decade was not obviously found, therefore, the results should be meaningful to future breeding for resistance to SCN in Huang-Huai Valleys.     

树干注射和根施农药控制松材线虫病试验

采用树干注射16%虫线清乳油500 mL/L溶液兼根施3%呋喃丹颗粒剂的施药技术,对重点风景名胜区、佛教胜地、重要生态区域松材线虫病发生区50年以上的马尾松实施保护性防治,取得了良好的防治效果,与对照区比较,防治后的第1~3年,病死树分别减少51.6%-52.9%、39.8%-80.9%和100%,有效地保护了具重要价值的马尾松树林和生态环境安全。     

不同土壤处理剂对设施蔬菜黄瓜根结线虫防治技术研究

为了筛选蔬菜根结线虫的防治技术,在赤峰市进行了7种不同土壤处理药剂对黄瓜根结线虫的防治效果田间试验,结果表明,应用7种不同土壤处理药剂进行土壤处理,揭膜放气5d后定植黄瓜,对黄瓜生长无不良影响,而且对根结线虫均有较好的抑制作用,其中98.1％1,3-二氯丙烯-氯化苦复配胶囊16 kg/667 m2、95％1,3-二氯丙烯液剂65 kg/667m2及10％液体石灰氮65 kg/667m2对黄瓜根结线虫的防治效果达90％左右,优于目前生产中常用药剂42％威百亩水剂6 kg/667m2和10％噻唑磷颗粒剂2 kg/667m2的防治效果,并且可以显著地提高黄瓜产量,适于在设施蔬菜生产上推广使用.     

卵巢线虫(Contortylenchus genitalicola)在中国松褐天牛上的分布与作用研究

[目的]日本学者Kosaka与Ogura发现松褐天牛成虫除携带松材线虫外,雌成虫卵巢内还携带有另一种线虫,他们将其命名为卵巢线虫,并认为这种线虫是松褐天牛成虫的寄生性线虫。我国对该种线虫的研究迄今未见报道。为了证明这种线虫在我国是否存在和分布,开展了本项研究。[方法]分期分批捕获刚羽化的松褐天牛雌雄成虫,采用解剖松褐天牛成虫松树木质部及感病的松褐天牛幼虫等方法,调查卵巢线虫的存在与分布。[结果]通过调查研究,发现我国的松褐天牛成虫体内有该卵巢线虫存在,分布于松褐天牛成虫、幼虫体内和松树木质部3个部位;在松褐天牛成虫体内的卵巢线虫通过松褐天牛雌成虫产卵而接种、进入寄主树木木质部中。同时,木质部的卵巢线虫也有一部分进入松褐天牛幼虫体内寄生,另一部分仍在木质部生活,当松褐天牛幼虫再次发育为成虫时,在木质部中的卵巢线虫和已被寄生的松褐天牛幼虫体内的卵巢线虫再次进入松褐天牛成虫体内,完成循环。卵巢线虫在松褐天牛雌、雄虫体内均有分布,携带率为44.4%,其中松褐天牛雌成虫携带率为43.8%,松褐天牛雄成虫携带率为45.0%,两者间无显著差异;每头松褐天牛成虫平均携带卵巢线虫574条,其中雌成虫平均携带816条,雄成虫平均携带308条,具显著差异。初步研究表明,卵巢线虫在松褐天牛成虫体内只能完成产卵到1~4龄的幼虫阶段,不能完成一个完整的世代;在松褐天牛幼虫体内寄生和在木质部生活的卵巢线虫能完成一个完整世代,但具体过程尚不清楚;调查中未观察到卵巢线虫对松褐天牛成虫有寄生致病或致死的现象,但对松褐天牛幼虫有寄生致死的能力;卵巢线虫常与松材线虫同时存在,而且侵入松树及离开松树的方式与松材线虫相同。[结论]我国松褐天牛体内也发现有卵巢线虫存在;目前尚不能证明该线虫对松褐天牛成虫具有寄生致死性,但对松褐天牛幼虫具有一定的寄生致死性;卵巢线虫的生活史与松材线虫相似,是否与松材线虫一样对松树具有危害性以及其病理作用还有待于进一步研究。     

大豆胞囊线虫病的生防因子研究进展

综述了大豆胞囊线虫的各类生防因子,如食线虫真菌、食线虫细菌、杀线虫植物、捕食性线虫和捕食性土壤动物等,其中研究较深入的是食线虫真菌和细菌,食线虫真菌可归纳为5种类型,即捕食性真菌、专性内寄生菌物、机会真菌、产毒真菌和菌根菌;另外,还对其他生防因子的最新研究结果进行了归类综述,并对大豆胞囊线虫的生物防治进行了展望。     

小麦禾谷孢囊线虫湖北群体活动期特性

小麦播种时定量接种禾谷孢囊线虫（ＣＣＮ）（Ｈｅｔｅｒｏｄｅｒａａｖｅｎａｅ）的孢囊,发芽生根后进行系统观察,结果表明,该线虫在小麦生长季节中完成１代,小麦播种后２５～３５ｄ是２龄幼虫入侵幼根的高峰期,１００～１２０ｄ根内出现３龄幼虫,１１０～１３０ｄ发育成４龄幼虫,１３０～１５０ｄ根表露出白色孢囊（雌虫）。受感染的麦根,侵染点首先变褐,进而肿大,常见分叉增多,形成须根团,ＣＣＮ多居于自然含磷,钾元     

Strong bottom-up and weak top-down effects in soil: nematode-parasitized insects and nematode-trapping fungi

The soils of the Bodega Marine Reserve (BMR, Sonoma County, California) contain many nematode-trapping fungi and many ghost moth larvae parasitized by entomopathogenic nematodes. The current study determined whether these nematode-parasitized moth larvae, which can produce very large numbers of nematodes, enhanced the population densities of nematode-trapping fungi and whether the fungi trapped substantial numbers of nematodes emerging and dispersing from moths. Wax moths were used in place of ghost moths because the former are easier to obtain. When nematode-parasitized moth larvae were added to laboratory microcosms containing BMR field soil, the population densities of four nematode-trapping fungi increased substantially. The greatest increase in population density was by Arthrobotrys oligospora, which uses adhesive networks to capture nematodes. A. oligospora population density increased about 10 times when the added moth larvae were parasitized by the nematode Heterorhabditis marelatus and about 100 times when added moth larvae were parasitized by the nematode Steinernema glaseri. Other trapping fungi endemic to the soil and enhanced by nematode-parasitized moth larvae included Myzocytium glutinosporum, Drechslerella brochopaga, and Gamsylella gephyropaga, which produce adhesive spores, constricting rings, and adhesive branches, respectively. The data suggest that the previously documented abundance and diversity of nematode-trapping fungi in BMR soil can be explained, at least in part, by nematode-parasitized insects, although that inference requires further studies with ghost moths. The strong bottom-up enhancement of nematode-trapping fungi was not matched by a strong top-down suppression of nematodes, i.e. the fungi trapped fewer than 30% of dispersing nematodes.