番茄抗性品种与黄瓜轮作对根结线虫的防治作用

通过室内盆栽试验探讨对根结线虫具有不同抗性的番茄品种与黄瓜轮作减轻根结线虫病危害的可行性。试验结果表明:抗性品种多菲亚能极大降低土壤中根结线虫2龄幼虫和卵的密度,减轻黄瓜根结线虫病的危害;抗性砧木Beaufort也能显著地降低土中根结线虫和卵的密度,但下茬黄瓜根结线虫的危害与对照相比没有显著差异。表明抗性品种与感病品种轮作能有效地防止根结线虫的发生。     

长枝木霉菌株TL16防治南方根结线虫的作用机理

为探明长枝木霉Trichoderma longibrachiatum菌株TL16防治南方根结线虫Meloidogyne incognita的作用机理,采用原生质体转化法获得绿色荧光蛋白(green fluorescent protein,GFP)标记菌株GFP-TL16,通过测定菌株TL16和GFP-TL16对南方根结线虫卵和2龄幼虫(2nd-stage juvenile,J2)的寄生与致死作用,其发酵液对卵孵化的抑制作用和对J2的致死作用,以及菌株GFP-TL16在黄瓜根系的定殖情况和菌株TL16对番茄根结形成的抑制作用来综合分析其作用机理。结果显示:菌株TL16菌丝对南方根结线虫卵无寄生作用,处理19 d后卵降解率为26.33%,致死作用较低;菌株TL16分生孢子悬浮液处理南方根结线虫J2后72 h的致死率为1.65%,且无寄生作用。菌株TL16发酵液处理南方根结线虫J2后48 h的校正死亡率为10.71%,处理卵15 d后对卵孵化的相对抑制率为77.11%。菌株GFP-TL16可定殖于黄瓜根系中,经菌株TL16处理后接种南方根结线虫J2,番茄根结减退率为55.88%。表明长枝木霉菌株TL16可通过抑制根结线虫卵孵化和诱导番茄产生抗病性来防治根结线虫病。     

施用生防菌菌剂与日光消毒和生物熏蒸相结合防治番茄根结线虫的研究

在温室条件下,研究了覆膜日光消毒、有机物料生物熏蒸和接种根结线虫拮抗菌Bacillus cereus X5对番茄生物量、根结线虫侵染以及根际土壤和土体土壤中微生物数量变化的影响。结果表明,对根结线虫滋生土壤进行覆膜日光消毒、生物熏蒸和接种拮抗菌的联合处理效果最佳,优于单一处理。联合处理的番茄生物量干重比对照增加了1.8倍;每株番茄根结线虫卵块数和每卵块的虫卵数量分别减少了190.4%和380.5%,对根结线虫的防治效果达到82.7%;根际土壤和土体土壤的细菌和真菌数量显著增加;土壤中根结线虫的数量显著减少。     

青霉菌Snef1216发酵液诱导番茄抗南方根结线虫研究

 通过Snef1216发酵液处理番茄根系和包衣种子,研究番茄抗南方根结线虫的组织病理学变化和作用方式。结果显示:处理番茄根系且接种15 d,应答根系内根结线虫的数量减少47.5%,且巨细胞出现空泡;包衣番茄种子,接种4、8和12 d,根系内2龄幼虫分别减少54.1%、3.4%和41.7%,接种10、20和30 d,根系内2龄、3龄、4龄幼虫和雌虫的数量也均比对照组番茄明显减少。表明Snef1216发酵液诱导了番茄对南方根结线虫的抗性。     

聚多曲霉Snef210对南方根结线虫毒性的研究

蔬菜根结线虫病在我国乃至世界危害日益严重,安全防控该病害成为目前急需解决的农业生产问题。本研究筛选到一株可毒杀南方根结线虫Meloidogyne incognita的生防真菌Snef210,经形态学和分子生物学鉴定为聚多曲霉Aspergillus sydowii(Bain.et Sart.) Thom et Church。该菌株发酵液对南方根结线虫2龄幼虫(J_2)具有很强的毒杀作用,原液处理24 h后校正死亡率达90.1%,处理3 d后对卵孵化的抑制率达92.8%。盆栽试验中,与对照相比,菌株发酵液10倍稀释液土壤处理对番茄根部的根结减退率为66.7%。聚多曲霉代谢产物丰富,多用于抗菌和抗肿瘤的研究,本文首次发现其对南方根结线虫有效,是一类潜在的控制植物线虫病害的新型生防因子。     

辽宁省保护地蔬菜根结线虫发生规律及防治对策*

2008-2009年,对辽宁省蔬菜主产区保护地蔬菜根结线虫病的危害程度进行调查,以辽宁省的辽中、辽西、辽南、辽东4个地区的黄瓜大棚为对象,对棚内土壤中根结线虫的发生规律进行系统研究。结果表明：辽宁省保护地蔬菜根结线虫病为南方根结线虫危害。该病在辽宁省保护地蔬菜上发生已相当普遍,其中以连作7年以上的黄瓜、番茄、苦瓜易感寄主为主的老菜棚的发病率达到100%,病情指数达到80以上。4个地区大棚土壤中根结线虫数量普遍随土层的加深呈明显减少的趋势;并且根结线虫数量普遍随着大棚前边缘向内的距离加大呈明显增加的趋势。结合辽宁省根结线虫发病特点,提出相应的防治措施。     

新型农药氟吡菌酰胺对番茄根结线虫的田间防效

为测试新型杀线虫剂41.7%氟吡菌酰胺悬浮剂对番茄根结线虫病的防治效果,以1.8%阿维菌素乳油和10%噻唑膦颗粒剂为对照药剂,进行了田间防治试验。结果表明,41.7%氟吡菌酰胺悬浮剂138倍液(灌根)、1.8%阿维菌素乳油1000倍液(灌根)、10%噻唑膦颗粒剂22.5 kg/hm~2(拌土)处理的防效分别为76.0%、44.0%、52.0%。氟吡菌酰胺对于番茄根结线虫的控制效果显著高于对照药剂。氟吡菌酰胺能够抑制番茄根部根结的形成,控制土壤中根结线虫2龄幼虫数量,促进植株生长,增产率达到133.2%。     

土壤药剂处理结合阳光消毒防治番茄根结线虫技术评价

为了筛选安全、高效、实用的化学防治技术,对国内外生产的5种杀线虫剂(棉隆、1,3 二氯丙烯·氯化苦、威百亩、噻唑磷、溴甲烷)土壤处理结合阳光消毒防治番茄根结线虫的效果进行了评价。结果表明,使用98%棉隆微粒剂450 kg/hm2或10%噻唑磷颗粒剂30 kg/hm2防治番茄根结线虫(Meloidogyne incognita),结合夏季高温进行阳光消毒,能有效地降低番茄根结线虫的数量,减轻根结线虫的危害程度,节省农户的生产成本,提高番茄的产量和农户的经济效益,是夏季防治番茄根结线虫的有效措施。     

棚室蔬菜根结线虫病的发生与防治

<正>近年来,随着农业种植结构的调整,保护地蔬菜栽培面积迅速发展,为根结线虫的发生、发展提供了适宜的环境,使土壤中的根结线虫得以积累。连作温室的黄瓜和番茄受害更加严重,常造成蔬菜减产。笔者对吉水县黄瓜和番茄根结线虫病进行调查与研究,并提出防治措施,以减轻根结线虫的发生和为害。1症状黄瓜和番茄根结线虫主要发生在须根或侧根     

一种准确测定土壤根结线虫种群数量的方法

为探索一种准确测定土壤根结线虫种群数量的方法,采用NaOCl消解附着在土壤病残体上的根结线虫卵囊与线虫常规离心技术相结合的方法,测试了不同NaOCl浓度、离心时间对根结线虫回收效率的影响,筛选出最佳测定条件,并与浅盘法、离心法、Byrd法等线虫常规分离方法进行了比较。结果表明,在9个NaOCl处理浓度中,1.0%~2.5%NaOCl处理对土壤根结线虫的回收效率显著高于3.0%NaOCl处理,达到71.6%~99.4%。在1.0%、1.5%、2.0%和2.5%NaOCl处理30 s后,分别离心2~5、2~3、2~3 min和2 min对根结线虫的回收效率明显高于其它时间处理,在每50 m L土壤平均接种976粒线虫卵的人工病土中,上述处理分离线虫数量分别达到804.3~930.0、810.7~838.7、843.7~867.0和820.7。本研究的改良方法对自然病土中根结线虫的分离数量分别是浅盘法、离心法和Byrd法的29.3、13.4和2.1倍,显著提高了土壤中根结线虫的分离效率,可准确测定土壤根结线虫种群的数量。     

Root exudates of potato onion are involved in the suppression of clubroot in a Chinese cabbage-potato onion-Chinese cabbage crop rotation

Clubroot, caused by Plasmodiophora brassicae, has emerged as a serious disease threatening cruciferous crop production throughout the world. Crop rotation with non-host species is commonly practised to avoid clubroot, but it is not known whether rotation crops can control clubroot when the resting spores of P. brassicae remain unaffected. Pot experiments were performed to investigate the response of clubroot in Chinese cabbage to crop rotation with potato onion. The results showed that Chinese cabbage rotated with potato onion exhibited less clubroot disease than Chinese cabbage monoculture. Compared with residues from potato onion, the addition of root exudates from potato onion significantly decreased the disease incidence and index of clubroot (p ≤ 0.05). Potato onion root exudates decreased the number of secondary plasmodia of P. brassicae and the expression of the PRO1 gene of P. brassicae. These results suggest that root exudates from potato onion may play an important role in suppressing clubroot in a Chinese cabbage-potato onion-Chinese cabbage rotation system.     

茶苗根结线虫病研究

 茶苗根结线虫病主要发生于一、二年生实生苗上,重病地发病率可达100%,死苗率在50%以上。据在浙江省的不完全调查,已知有18个县(市)发现此病。病原线虫经初步鉴定,主要为南方根结线虫(Meloidogyne incognita)与花生根结线虫(M.arenaria),而爪哇根结线虫(M.javanica)与泰晤士根结线虫(M.thamesi)均少见。试验表明,杭州茶区病原线虫一年发生不完整8代,大约20~30天完成一代,世代重叠明显。     

西南部分地区荞麦根结线虫种类与地理分布

近年来,随着我国荞麦面积的迅速增加,根结线虫病呈逐年加重趋势,严重影响了荞麦的产量与品质。本研究于2014年对西南10个地区17个乡镇秋播苦荞麦根结线虫的分布、发生种类以及危害程度进行了调查。结果表明,西南地区危害荞麦的根结线虫种类有南方根结线虫(Meloidogyne incognita)、爪哇根结线虫(M.javanica)和花生根结线虫(M.arenaria)3种,其中南方根结线虫为优势种群。田间根结线虫种群大多数为单一种群,23.5%的样品为南方根结线虫与爪哇根结线虫(或花生根结线虫)组成的混合种群。调查发现前作为烟草或马铃薯的地块,荞麦根结线虫发生危害严重,平均被害株率为6.0%~77.5%,病情指数为1.4~26.1,而前作为玉米的荞麦根结线虫则较轻,被害株率最高为16.0%,相应病情指数为2.3。     

假格里尼翁苍白杆菌A-29对南方根结线虫的防治效果及其鉴定

南方根结线虫是一种重要的植物寄生线虫，严重发生时可造成巨大的经济损失。本研究测定了菌株A-29发酵液对南方根结线虫的致死效果和盆栽防效，并对其进行了种类鉴定。结果表明，菌株A-29发酵滤液原液、5倍液和10倍液处理南方根结线虫后，2龄幼虫的致死率在24 h和48 h后达71.09%～95.45%，卵的孵化抑制率4 d时为59.25%～87.86%，其死亡率随处理浓度的提高而增加；菌株A-29发酵液处理60 d后对番茄根结线虫的防治效果达75.00%，番茄植株鲜重、根系干重和植株高度分别增加38.41%、33.52%和20.01%；根据菌株A-29的形态特征、生理生化特征、16S rRNA基因序列及其系统发育关系，将其鉴定为假格里尼翁苍白杆菌Ochrobactrum pseudogrignonense。研究表明，菌株A-29不仅对南方根结线虫具有良好的致死效果，而且对番茄植株具有明显的促生作用，是一株具有应用前景的生防菌。     

防治南方根结线虫的根瘤内生细菌的筛选及鉴定

根结线虫的严重发生给农作物生产造成巨大经济损失，生物防治是控制该病的一种安全有效措施。本研究从448株根瘤内生细菌分离株中筛选出3株对南方根结线虫有较好防效的生防细菌Sneb1994、Sneb1995和Sneb2000，3个菌株发酵滤液对南方根结线虫2龄幼虫（J2）均有高毒杀活性，处理24 h校正死亡率达85%以上，同时对卵孵化具有抑制作用，并可促进番茄种子生长。盆栽试验结果表明，3个菌株发酵液灌根处理均能显著减少根结数和卵囊数，相对防效为37.95%~44.51%，同时促进番茄植株的生长。经形态特征、生理生化特性和16S rDNA序列分析，鉴定菌株Sneb1994、Sneb1995和Sneb2000分别为氧化微杆菌Microbacterium oxydans、油菜假单胞菌Pseudomonas brassicacearum和蜡样芽胞杆菌Bacillus cereus。氧化微杆菌为首次报道对根结线虫有效的生防菌株。这些根瘤内生细菌菌株的发掘，为植物线虫病害的生物防治提供了新的微生物资源。     

Local and Systemic Induced Resistance to the Root-Knot Nematode in Tomato by DL-beta-Amino-n-Butyric Acid

ABSTRACT Chemical inducers of pathogenesis-related proteins and plant resistance were applied to tomato plants, with the aim of inducing resistance to the root-knot nematode Meloidogyne javanica. Relative to control plants, foliar spray and soil-drenching with dl-beta-amino-n-butyric acid (BABA) reduced root-galling 7 days after inoculation, as well as the number of eggs 30 days after inoculation. Other chemicals (alpha- and gamma-amino-n-butyric acid, jasmonic acid, methyl jasmonate, and salicylic acid) were either phytotoxic to tomato plants or did not improve control of root-knot nematodes. Fewer second-stage juveniles invaded BABA-treated tomato roots, and root-galling indices were lower than in control tomato plants. Resistance phenomena in seedlings lasted at least 5 days after spraying with BABA. Nematodes invading the roots of BABA-treated seedlings induced small, vacuolate giant cells. Postinfection treatment of tomato plants with BABA inhibited nematode development. It is speculated that after BABA application tomato roots become less attractive to root-knot nematodes, physically harder to invade, or some substance(s) inhibiting nematode or nematode feeding-site development is produced in roots.     

Dry mycelium of<Emphasis Type="Italic">Penicillium chrysogenum</Emphasis> protects cucumber and tomato plants against the root-knot nematode<Emphasis Type="Italic">Meloidogyne javanica</Emphasis>

Incorporation into soil of dry mycelium ofPenicillium chrysogenum, a waste product of the pharmacological industry, enhanced plant growth and reduced root galling caused by the root-knot nematodeMeloidogyne javanica in cucumber and tomato plants. Incorporation into sandy loam soil in pots of dry mycelium at a concentration of 0.25% (w/w) resulted in complete protection of cucumber plants from the nematode. The number of juveniles recovered from soils containing dry mycelium was greatly reduced even at a concentration of 0.1% (w/w). In microplot studies conducted at two sites in two seasons, with three or four doses, dry mycelium caused a dose-dependent reduction in root galling index (GI) and promotion of plant growth of cucumber and tomato plants. Inin vitro studies, the water extract of dry mycelium immobilized nematode juveniles and reduced the egg hatching rate, but these effects were partly reversible after a rinse in water. Soil-drenching of cucumber and tomato seedlings with water extract of dry mycelium did not reduce GI or number of root-invading juveniles. The results show that dry mycelium promotes plant growth and protects plants against nematode infection. Protection, however, does not operatevia induced resistance. http://www.phytoparasitica.org posting April 6, 2003.