Resistance analysis of the rice variety Huaidao 5 against root-knot nematode Meloidogyne graminicola

Meloidogyne graminicola has emerged as one of the most destructive plant-parasitic nematodes affecting rice(Oryza sativa)production worldwide.Resistance to M.graminicola in rice could be the most effective option for its management.However,sources of germplasm with resistance to M.graminicola in rice remain limited.Here,we describe the root attraction,gall formation and genetic analysis of the resistance to M.graminicola in the rice variety Huidao 5.A nematode attraction assay showed that second-stage juveniles(J2s)of M.graminicola were attracted at the root tip of Huaidao 5 within 8 h without a significant reduction in attraction compared to the susceptible rice variety Nanjing 9108.Microscopic observation of the infection revealed that the J2s invaded root tissues 12 h after inoculation,but their subsequent movement to the root tip was hindered in Huaidao 5,resulting in decreased nematode number compared to Nanjing 9108.Additionally,we used the soil and hydroponic culture systems to simulate upland and flooding conditions in the paddy fields respectively,and found that gall number was significantly reduced,and nematode development was clearly suppressed in Huaidao 5.To investigate the genetic basis of this resistance,cross breeding was performed between the Huaidao 5 and Nanjing 9108 varieties.There was no reduction in the resistance of the F_(1) offspring to M.graminicola in the greenhouse or field trials,suggesting that a dominant gene could control resistance in Huaidao 5.In summary,this study provides a detailed characterization of a novel source of resistance to M.graminicola in rice,which is of great potential for use in crop breeding.

Determination of Nematicidal Effects of Some Biopesticides against Root-Knot Nematode （Meloidogyne incognita） on Kiwifruit

The aim of this study was to determine the nematicidal effects of some biopesticides againist root-knot nematodes （RKNs） （Meloidogyne incognita） on Bruno type kiwifruit seedlings. Research was conducted in the Atattirk Central Horticultural Research Institute （ACHRI, Yalova, Turkey） greenhouse during 2013-2014. Biopesticides observed in this study were： sesame oil （Devalone EC）, castor oil （Ricinus communis）, Myrothecium verrucaria （M. verrucaria strain AARC-0255, Inferno DF）, Glomus spp. （Endomycorrhizal fungi, Endo Roots Soluble SP） and Paecilomyces lilacinus （Entomopathogenic fungi, P. lilacinus strain PL1, Bionematon SL）. Nematicide Nemacur EC 400 （fenamiphos） was used as treated control （TC） and trials were set up as randomized parcel design （RPD） with seven characters and 10 replicates. Reproduction ratio was determined according to scale values in trial applications and second stage juvenile （J2） populations of M. incognita in soil. The results showed that the best nematicidal effects against RKNs were determined in castor oil （77.92% in 2013 and 73.61% in 2014） and P. lilacinus （61.03% in 2013 and 55.55% in 2014）.

Efficiency of Some Plant Essential Oils on Root-Knot Nematode Meloidogyne incognita

During the last few decades, researchers have been in the search for environmental friendly ways to cope with agricultural pests, instead of using chemical pesticides. The use of essential oils has a high potential to become an alternative control strategy against plant parasitic nematodes. This study was conducted to determine the toxicity of 10 essential oils （Artemisia absinthium, Citrus bergamia, Eucalyptus citriodora, Hypericum perforatum, Lavandula officinalis, Mentha arvensis, Ocimum basilicum, Piper nigrum, Thymus serpyllum and Zingiber officinale） against the second stage juveniles of the root-knot nematode Meloidogyne incognita. The aqueous solutions of these essential oils have been applied to the second stage juveniles in three different concentrations （1%, 3% and 5%） at four different application time intervals （12, 24, 48 and 72 h）. The interactions between the variables have been examined with repeated measure analysis of variance （ANOVA）. This showed that the interactions of essential oil-time and essential oil-concentration were statistically significant, and it is concluded that L. officinalis, A. absinthium, P. nigrum, C. bergamia and M. arvensis have the most toxic effect in all concentrations and times, respectively.

RNAi of <i>MiASB</i>caused high mortality of <i>Meloidogyne incognita</i>juveniles and inhibited the nematode disease

The southern root-knot nematode, Meloidogyne incognita, is one of the most prevalent and damaging plant-parasitic nematodes in the world and causes serious damages to agricultural production. We cloned a mitochondrial ATP synthase b subunit gene fragment of M. incognita (MiASB) based on the nematode genomics prediction. By soaking in the MiASB dsRNA solution, the hatching of RNAi treated eggs was reduced by 60% compared to negative control and by 64% compared to untreated control. Mortality of RNAi treated second stage juvenile (J2) was 8.6 times higher than that of negative control and 26 times higher than the untreated control. Inoculating the RNAi treated egg masses and J2 to tomato seedlings showed the pathogencity was significantly reduced. For the RNAi treated egg masses, the amount of root galls on silence treated seedlings was reduced by 92% compared to that on the negative control seedlings, and reduced by 93% compared to that on untreated control seedlings. For the treated J2, the amount of root galls on silence treated seedlings was reduced by 83% and 86% compared to negative and untreated control seedlings, respectively. The study revealed the MiASB silence had a positive effect on prevention and control of root-knot nematode disease, and also showed that the MiASB may be involved in the pathogenesis of nematode, which provided new ideas and ways to the research of nematode pathology and nematode disease control.

Effect of Pleurotus ostreatus on Dynamics of Meloidogyne arenaria Population and Control Effectiveness

The control effects and application methods of Pleurotus ostreatus on the peanut root-knot nematode disease, Meloidogyne arenaria, were systematically studied in the greenhouse. Results of pot experiments showed that P. ostreatus could effectively reduce the 2nd-instar population density in the soil, and the larva reduced by 80% compared with the control. P. ostreatus could markedly lower the infecting number of the peanut root-knot nematodes, the nematode density inside the root knots declined by 40.00% -82.64%, and the peanut root knots also reduced by 86.96% - 94. 03%. The fungus could defer the initial infection of M. arenaria to the roots, the epidemic rate of the peanut root-knot nematode disease was significantly cut down, and the increase of root-knot changed from the way of Logistic curve in the control to the way of linear curve in the treatment. The final control effectiveness was about 80%. The results of pot trial also indicated that the control effectiveness is closely related to the application time and the amount of this fungus. The key factor affecting control effectiveness was the application time of P. ostreatus in the soil and the suitable time was 20 days before sowing.

A New Host for Meloidogyne incognita （Kofoid ＆ White 1919） Chitwood, 1949 （Nemata： Tylenchida） in Turkey： Potato

Potato is the main material of nutrition comes after the wheat and, is subjected to attacks of different plant parasitic nematodes which cause serious damages in our country. Especially, root-knot nematodes cause serious crop losses on them. Due to usage oflnfested seeds, parasitic nematodes are increasing from year to year. In our country, so far, many infested hosts of Meloidogyne incognita （Kofoid ＆White, 1919） Chitwood, 1949 were detected but there is no report on investigation on potato. During this study, adult females of root-knot nematodes were obtained via extracting gals of 133 tuber samples, collected potatoes fields in the Marmara region especially Balikesir, Bilecik, Bursa, Canakkale, Edirne, Istanbul, Kirklareli, Kocaeli, Sakarya and Tekirdag provinces during 2007-2008. During identification the species, second stage larvae were taken into consideration as well as genital preparations of adult females. For the identification classical methods were used together with molecular methods. As result, M. incognita was detected, only species detected among the Meloidogyne genus upon the 10 provinces investigated in Edirne province, Bosna village. This is the first report of the infestation of this species potato and also in Marmara Region.

辣(甜)椒根结线虫的危害、防治和抗病育种

对辣(甜)椒根结线虫的危害和防治方面的文献作了简要的总结和评述,重点介绍了抗根结线虫育种的进展和方向,包括苗期接种技术、种质资源的收集和利用、抗病基因、育种策略,并对提高我国辣(甜)椒根结线虫的防治和抗病育种水平提出建议。

引入小麦秸秆抑制番茄根结线虫病

为了研究引入秸秆碳源对土壤根结线虫(Meloidogyne spp.)病害的抑制效果,以番茄为供试作物,设置3个梯度的小麦秸秆添加量进行了为期6个月的室内盆栽试验。结果表明:引入小麦秸秆能够抑制根结线虫病害的发生,但添加秸秆量过多会对番茄的生长产生负面作用。以华北农田小麦秸秆还田模式平均输入量为基本单位N,秸秆添加量为1N(2.08g/kg)、2N(4.16g/kg)、4N(8.32g/kg)时对根结线虫病的抑制率分别是:51.4%,94.0%,39.5%;当秸秆添加量为1N、2N时,番茄的株高、茎粗、开花率等指标没有明显下降,但当秸秆添加量升高至4N时,这些指标均明显下降。引入小麦秸秆后,土壤线虫群落结构发生了变化,植食性线虫的比例均有所下降,而食细菌、食真菌和杂食捕食性线虫的比例均有所上升。1N,2N,4N3个处理植食性线虫的比例分别下降了17.6%,97.3%和2.0%,而食细菌线虫的比例分别上升了100.5%,189.7%和117.8%,其中2N处理的线虫群落结构变化幅度最大;食真菌线虫的比例在4N处理中显著上升,增长率为350%,而杂食捕食性线虫则在1N处理中明显上升,增长率为66.7%。综合番茄生长指标、对根结线虫抑制率及土壤线虫群落结构变化3方面的结果,添加秸秆量为2N时对番茄根结线虫病的抑制效果最好。

木醋液的杀线活性及对根结线虫病的防治效果研究

【目的】初步探究木醋液对根结线虫2龄幼虫的抑制作用,以及木醋液及其配剂对根结线虫病的田间防治效果。【方法】采用浸渍法测定不同稀释浓度的木醋液对根结线虫2龄幼虫抑制作用,根据实验室测定结果设计小区试验,进行木醋液及其配剂对石榴根结线虫病、番茄根结线虫病的大田防治。【结果】不同稀释浓度的木醋液对4种常见根结线虫的2龄幼虫均有抑制作用,随着稀释倍数的增加,抑制作用减小。木醋液稀释浓度为150倍处理72h时,北方根结线虫、花生根结线虫、南方根结线虫、爪哇根结线虫的校正死亡率分别达到了76.3%、78.4%、77.9%和72.2%。木醋液和木醋液配剂对石榴根结线虫病有较好的防治效果,防治效果分别达到了63.9%和50.5%。木醋液和木醋液配剂对番茄根结线虫病的防治效果,寻甸分别为54.1%和28.6%,个旧的为27.8%和19.6%。【结论】初步证明木醋液对根结线虫2龄幼虫有抑制作用,对石榴根结线虫病和番茄根结线虫病有防治效果,对防治根结线虫病有研究价值、应用价值和开发前景。

河南省烟草根结线虫种类的PCR鉴定与种群分析

为明确河南省烟田根结线虫种群分布及比例,采集了12份烟草根结线虫样本。通过对线虫样本的PCR分子检测和雌成虫会阴花纹的形态鉴定,结果表明,检出烟草根结线虫4种,其中南方根结线虫(Meloidogyne incognita)检出率为55.83%,花生根结线虫(Meloidogyne arenaria)23.33%,北方根结线虫(Meloidogyne hapla)17.50%;爪哇根结线虫(Meloidogyne javanica)3.33%。种群分析表明河南地区仍以南方根结线虫为主,同时其他种类根结线虫的发生危害比例在上升。所有样本均为混合侵染,南方根结线虫、花生根结线虫和北方根结线虫在河南广泛分布,具有普遍性;爪哇根结线虫在河南分布没有规律性。

种植诱集植物对土壤中根结线虫种群数量的影响

对种植油麦菜、大白菜、普通白菜、叶用莴苣及菠菜5种诱集植物前、后土壤中根结线虫的数量变化进行了研究,结果表明:种植诱集植物明显减少了土壤中根结线虫的数量,其中油麦菜对10～30cm土层中根结线虫的控制效果最好,校正虫口减退率达60%以上。对5种诱集植物的根结线虫病情调查表明,5种诱集植物的发病率均达到100%,油麦菜、叶用莴苣、普通白菜、大白菜及菠菜病情指数分别为50.0、29.6、28.4、33.3及25.6。

DFRKN-1碱性磷酸酶的提取纯化和主要理化性质研究

[目的]提取纯化根结线虫天敌真菌-1(Destroying fungi of root-knot nematode-1,DFRKN-1)的碱性磷酸酶,并对其主要理化性质进行研究。[方法]以DFRKN-1为提酶材料,经正丁醇提取,硫酸铵分级沉淀分离,透析获得酶的粗提取液,用SephadexG-150凝胶过滤柱层析纯化,获得纯化碱性磷酸酶,并测定纯化碱性磷酸酶的理化性质。[结果]酶纯度达到电泳纯,提纯倍数达到15.7倍,比活力达5333 U/mg;该酶的最适pH值为8.9,最适温度为43℃,米氏常数为6.82 mmol/L;K+、Ba2+、Mg2+对该碱性磷酸酶的活性均有激活作用,甲醛、草酸、酒石酸对该碱性磷酸酶均有抑制作用。[结论]试验结果可为进一步深入研究DFRKN-1提供参考。

海南岛主要栽培果树的根结线虫病及其防治

调查了海南岛20种主要栽培果树的根结线虫病的发生情况,鉴定了病原线虫的种类,试验了5种杀线虫药剂的防治效果。结果表明:番石榴、香蕉、皇帝蕉、粉蕉、火龙果与番木瓜6种果树不同程度感染根结线虫病(前3种最敏感),株发病率80%～100%,根结指数2.75～5.00;病原线虫有南方根结线虫(Meloidogyneincognita)、爪哇根结线虫(M.javanica)和花生根结线虫(M.arenaria),以及另外2个有待明确的虫种;7.5～15.0 kg/hm2的10% 福气多颗粒剂对土壤中二龄侵染幼虫的防效为84.15%～95.18%,同时可有效地抑制根结的形成。

“植物源线虫速杀剂”防治烟草根结线虫病的田间试验

为了替代高毒性、高残留、高成本的化学杀线剂,进行了"植物源线虫速杀剂"对烟草根结线虫病的防治效果田间试验。移栽时一次性施用"植物源线虫速杀剂"15%可湿性粉剂(30 kg/hm2,45 kg/hm2),"线敌"5%颗粒剂(27 kg/hm2)和"阿维菌素"5%颗粒剂(45 kg/hm2)3种生物杀线剂以及对照药物"铁灭克"(13.5 kg/hm2)处理。结果表明:应用两种剂量的植物源杀线剂均能够有效防治烟草根结线虫病。在烟田较干旱条件下,小面积示范试验结果"植物源线虫速杀剂"防效达66.55%～72.23%,高于"铁灭克",明显优于"线敌",而"阿维菌素"的防效相对较差,田间示范试验与小面积示范试验结果一致。

根结线虫病防治研究进展

简述了结线虫的种类及发病规律,详述了根结线虫病农业防治、化学防治、物理防治及生物防治方面的研究进展,扼要分析了该病防治上存在的问题,并展望了生物防治和抗根结线虫育种的前景。

根结线虫分类鉴定的原理和方法

根结线虫(Meloidogyne spp.)是严重危害植物的病原物,其种类繁多,常常造成毁灭性的危害。根结线虫的分类是防治其病害的基础和前提,形态学特征和分子生物学特征鉴定是主要的分类方法。根结线虫的形态学鉴定主要依据虫体的外部形态特征和内部结构特点进行分类鉴定。其根结线虫的分子生物学鉴定方法是通过分析核酸DNA、线粒体DNA等生物大分子的不同,检测根结线虫种群之间和种群内部在生物遗传物质组成上的特有差异,从而鉴别根结线虫种类。应将两种方法相互结合、取长补短,才能得到更准确的结果。

昆虫病原线虫共生细菌对南方根结线虫卵孵化的影响

为探讨不同种(品系)昆虫病原线虫共生细菌的不同稀释倍数对南方根结线虫Meloidogyne incognita卵孵化的影响,采用培养皿法进行室内生测,定期调查根结线虫卵孵化情况。结果表明,4种(品系)昆虫病原线虫(斯氏属两个种和嗜菌异小杆两个品系)共生细菌的10×稀释液,6 d时Hb-NJ共生菌使M.incognita的卵孵化率最低,为8.6%,以TSY培养液为对照,其孵化率为29.1%,Hb-NJ共生菌对M.incognita卵孵化的抑制作用最强,相对抑制率为70.6%,其它3种昆虫病原线虫Hb-IGA、Sc-All和Sf-IGA共生细菌的孵化率为分别为24%、22.6%和25.2%,其相对抑制率是17.2%、22.3%和13.4%;8 d时线虫Hb-NJ、Hb-IGA和Sc-All共生菌的相对抑制率分别为67.1%、39.3%和41.7%,10 d时4种(品系)昆虫病原线虫共生菌对M.incognita的孵化率和抑制率均无显著性差异(p>0.05)。4种(品系)昆虫病原线虫共生菌的20×和50×稀释液对M.incognita卵孵化没有明显的抑制作用。基于以上结果,Hb-NJ的共生细菌可以通过抑制南方根结线虫的卵孵化导致线虫群体下降而达到防治线虫的目的,因此是一种潜在的生物杀线虫剂。

臭氧水对茄子根结线虫的防治效果评价

根结线虫是具有毁灭性危害的植物内生寄生虫,臭氧水漫灌土壤是较为理想的替代化学药剂的防治方法,但还未见在茄子上使用的报道。为了探究高浓度臭氧水漫灌处理土壤对茄子根结线虫的田间防治效果及对茄子生长的影响,本研究在茄子定植前对土壤进行连续2次臭氧水(9 mg/L)漫灌处理,并对漫灌处理前后和茄子整个生长期的根结线虫病害发生情况及茄子生长情况进行跟踪调查。结果表明,与对照相比,结果期和生长后期根结线虫数量分别下降91.67%和95.97%;幼苗期、结果期和生长后期的防治效果分别为100%、55.36%和65.52%;处理样本的株高显著提高。因此,高浓度臭氧水漫灌处理土壤对茄子根结线虫的防治效果较好且可减少农药使用量,对茄子生长安全,值得推广应用。

Biochar from grape pomace,a waste of vitivinicultural origin,is effective for root-knot nematode control

Root-knot nematodes(RKNs)are obligate endoparasites that feed on their host plants to complete its life cycle,representing a major threat to agriculture and economy worldwide.The development of new management strategies becomes essential as effective chemical nematicides are progressively being restricted.Hence,we analysed grape pomace-derived biochars,pyrolysed at 350℃(BC350)and 700℃(BC700),focusing on their potential for RKN control.The thermal treatment of grape pomace caused an increase in the concentration of carbon and plant macro-and micronutrients,which were largely present in a water-soluble form.Synchrotron radiation-based Fourier transform infrared microspectroscopy data showed a general loss of carboxylic functional groups during pyrolysis,partially contributing to the alkalinisation of both biochars,mostly in BC700.Scanning electron microscopy coupled with energydispersive X-ray spectroscopy analysis revealed a highly porous structure filled with different crystals composed of elements such as K,Ca,Mg,P,Si or Al,which could be a suitable environment for the growth of microorganisms.Biochar-derived aqueous extracts showed phytotoxicity to tomato seedlings at high concentrations,and disappeared upon dilution,but no toxic effect was observed on the nematode’s infective stage.However,the infective and reproductive traits of a Meloidogyne javanica population in tomato were significantly reduced(i.e.egg masses and eggs per plant)in washed-biochar-treated soil in pots(0.75%;BC350W).Therefore,the large amount of grape waste generated after wine production can be transformed into a valuable product such as biochar,effective for RKNs control,thus reducing the waste management problem and contributing to a circular economy.

烤烟根结线虫病发生与土壤酶活性的相关性研究

为探究根结线虫发病与土壤酶活性之间的相关性,采集了玉溪市红塔区高仓街道和昆明市宜良县九乡乡植烟区的烤烟根际土壤样品,测定感病株和健康株根际土壤中的相关酶活性。结果表明:酸性磷酸酶活性与根结线虫发病呈显著性正相关,九乡和高仓试验区的根结线虫感病烟株根际土壤的酸性磷酸酶活性较健康烟株提高了474.82%和294.86%;九乡试验区根结线虫感病烟株根际土壤蔗糖酶、纤维素酶和过氧化氢酶活性分别较健康土壤下降50.19%、24.15%和56.02%,差异达显著性水平;高仓试验区根结线虫感病烟株根际土壤蔗糖酶、酸性蛋白酶、纤维素酶和过氧化氢酶活性分别较健康土下降30.62%、76.02%、19.85%和55.93%,均呈现显著性差异。