甘肃省党参根结线虫病发生、分布及病原种类鉴定

为明确甘肃省党参根结线虫病的发生、分布及病原种类,在甘肃省党参主产区调查、统计田间根结线虫病发生情况,并通过形态学和分子生物学方法进行种类鉴定。结果表明,甘肃省6个党参主产区均有根结线虫病发生,病田率、病株率分别为40.7%、13.2%,病情指数为10.4。依据根结线虫各虫态的形态测量值和雌虫会阴花纹等特征,将危害党参的根结线虫初步鉴定为北方根结线虫Meloidogyne hapla Chitwood, 1949。rDNA-ITS区段和28S rDNA D2D3区段序列比对和系统发育树显示,6个根结线虫群体无核苷酸差异,与多个北方根结线虫聚为一支且有较高的置信度。利用特异性引物Mh-F/Mh-R扩增得到北方根结线虫的特异性片段,大小为462 bp。故综合形态学和分子生物学特征,将危害甘肃省党参的根结线虫鉴定为北方根结线虫。     

红麻根结线虫病的初步研究

 根结线虫病是我国红麻上的一种主要病害。经4年在湖南、浙江、广东和广西等省(区)红麻主产区调查和鉴定,病原线虫有下列3个种: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)。南方根结线虫是优势种,其在湖南阮江县砂壤土麻田1年可发生4代。文中并对最佳施药期作了讨论。     

湖南省蔬菜根结线虫发生及种类鉴定

对湖南省蔬菜主产区的根结线虫病发生与危害程度进行了系统调查,结果显示蔬菜根结线虫病发生普遍,大棚蔬菜发病率高达80%,露地蔬菜发病率也在10%左右。对采自湖南省内10种蔬菜作物上的23个根结线虫种群进行了种类鉴定。采用2龄幼虫测量值、会阴花纹形态特征、PCR法及序列测定相结合的方法进行了鉴定,结果表明南方根结线虫是湖南省蔬菜根结线虫病的优势病原种群,占87%。     

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。     

河南省怀地黄根结线虫病发生分布与种类鉴定

对河南省焦作市田间辖区种植的怀地黄根结线虫病发生情况进行了调查与研究,并采用作物根结线虫特异性(sequence characterized amplified region SCAR)标记引物对其病原根结线虫PCR扩增检测,结合雌虫会阴花纹的比较形态学和rDNA-ITS区序列测序分析的方法对怀地黄病原根结线虫进行种类鉴定。结果表明,我国焦作地区怀地黄的根结线虫为南方根结线虫[Meloidogyne incognita (KofoldWhite) Chitwood]。本研究首次明确了河南省焦作地区怀地黄病原根结线虫为南方根结线虫。     

和田鞘氨醇杆菌AMCC 100218菌株的筛选、鉴定及杀线虫特性

为筛选对南方根结线虫具有致死效果的生防细菌,从山东省10个县市蔬菜主产区番茄根际土壤中分离可培养细菌,采用离体杀线虫试验测定分离菌株对南方根结线虫Meloidogyne incognita的致死活性,结合生理生化特征及分子生物学方法对高效杀线虫菌株进行分类鉴定,同时对其杀线虫特性进行表征,并通过盆栽试验进一步验证其生防潜力。结果显示,从山东省蔬菜主产区番茄根际土中分离到1株高效杀线虫菌株AMCC 100218,结合生理生化试验与16S rRNA序列分析,鉴定此菌株为和田鞘氨醇杆菌Sphingobacterium hotanense;该菌株对南方根结线虫2龄幼虫的致死效果可达88.87%,其杀线虫活性物质具有较好的热稳定性和储存稳定性,且耐碱不耐酸;盆栽试验结果表明,该菌能够显著减少土壤中的虫口密度,降低番茄发病率。表明和田鞘氨醇杆菌AMCC 100218菌株是1株具有防治根结线虫病潜力的生防细菌。     

根结线虫非中国种问题初探

根结线虫是十分重要的植物内寄生线虫,但种类鉴定十分困难,分类状况也较混乱。该文提出了口岸检疫根结线虫所遇到的难题,列出了40种在我国曾有报道的根结线虫,对根结线虫非中国种问题进行初探并提出建议。     

江西省山药病原线虫种类鉴定及地理分布

为明确江西省山药病原线虫的种类及地理分布,对采自主产区的157份山药样品进行了线虫分离与形态学鉴定,并对主要病原线虫种类进行rDNA-ITS和28S的序列比对和种群系统进化分析。形态学和分子鉴定结果表明：山药病原线虫种类为咖啡短体线虫Pratylenchus coffeae和南方根结线虫Meloidogyne incognita。调查结果表明,咖啡短体线虫在江西省大部分山药产区广泛分布,是优势种群。吉安市永丰县和泰和县山药线虫危害最为严重,山药样品中线虫检出率分别为66.7%和88.9%。南方根结线虫在江西省山药产区不是优势种群,呈零星发生。此外,山药样品中存在两种线虫的单一种群侵染和复合种群侵染,分别占总样品数的87.1%和12.9%。综上,本研究明确了江西省山药主产区病原线虫的优势种是咖啡短体线虫,为江西省山药病原线虫的科学防控提供了有价值的参考依据。     

四川省茂县花椒根结线虫病病原鉴定

为明确四川省茂县花椒根结线虫的种类,通过根结线虫雌虫和2龄幼虫的形态特征及雌成虫的会阴花纹、雌虫酯酶同工酶及分子生物学检测（rDNA-ITS区和rRNA-IGS区）,对花椒根结线虫进行了种类鉴定。三种方法的结果均表明在茂县地区花椒上发现的根结线虫为北方根结线虫（Meloidogynehapla）,这是我国首次报道在花椒上发现北方根结线虫病,四川省是北方根结线虫新的分布区。     

黄花倒水莲根结线虫病的病原鉴定

2019年在福建省多个地方发现黄花倒水莲Polygala fallax遭受根结线虫的严重侵染,为明确病原线虫种类,运用形态学、rDNA-ITS序列分析及特异引物PCR扩增的方法对分离获得的根结线虫进行种类鉴定。结果表明,该病原线虫为南方根结线虫Meloidogyne incognita。黄花倒水莲根结线虫病在我国为首次报道。     

北京地区保护地蔬菜根结线虫种类鉴定

从北京市9个区、县大型蔬菜生产基地的温室中采集蔬菜根结线虫样本21份,采用会阴花纹形态特征及分子生物学的方法对其进行了鉴定,结果表明北京地区温室中蔬菜根结线虫为南方根结线虫(Meloidogyne incogni-ta)。     

Histological Characterization of Resistance to Different Root-Knot Nematode Species Related to Phenolics Accumulation in Capsicum annuum

ABSTRACT In the pepper Capsicum annuum CM334, which is used by breeders as a source of resistance to Phytophthora spp. and potyviruses, a resistance gene entirely suppresses reproduction of the root-knot nematode (Meloidogyne spp.). The current study compared the histological responses of this resistant line and a susceptible cultivar to infection with the three most damaging root-knot nematodes: M. arenaria, M. incognita, or M. javanica. Resistance of CM334 to root-knot nematodes was associated with unidentified factors that limited nematode penetration and with post-penetration biochemical responses, including the hypersensitive response, which apparently blocked nematode migration and thereby prevented juvenile development and reproduction. High-performance liquid chromatography analysis suggested that phenolic compounds, especially chlorogenic acid, may be involved in CM334 resistance. The response to infection in the resistant line varied with root-knot nematode species and was correlated with nematode behavior and pathogenicity in the susceptible cultivar: nematode species that quickly reached the vascular cylinder and initiated feeding sites in the susceptible cultivar were quickly recognized in CM334 and stopped in the epidermis or cortex. After comparing our data with those from other resistant pepper lines, we suggest that timing of the resistance response and the mechanism of resistance vary with plant genotype, resistance gene, and root-knot nematode species.     

AM真菌和根结线虫互作对黄瓜生长及生理特征的影响

通过盆栽试验研究了丛枝菌根真菌Arbuscularmycorrhiza（AM）和南方根结线虫Meloidogyneincognita互作对黄瓜幼苗生长及生理特征的影响。结果表明,预先接种地表球囊霉Glomusversi—forme再接种线虫处理的鲜、干重较只接种线虫的处理显著增加;预先接种AM真菌再接种线虫处理的根结线虫病情指数、AM真菌侵染率较只接种线虫的处理明显降低;接种线虫使黄瓜植株的过氧化物酶（POD）、过氧化氢酶（CAT）及苯丙氨酸解氨酶（PAL）、总酚含量有不同程度提高,其中预先接种根内球囊霉G．intraradices对黄瓜植株起到了较好的保护作用;与对照相比,只接种线虫处理的叶片磷含量降低了25．26％,预先接种AM真菌再接种线虫处理的叶片磷含量较只接种根结线虫的含量高。     

陕西省首次发现象耳豆根结线虫危害洛南白菜

采用形态学鉴定、特异性引物鉴定及rDNA-ITS序列分析方法,对采自陕西省洛南县白菜的根结线虫进行了种类鉴定,并结合构建系统发育树,确定了感染洛南县白菜的根结线虫为象耳豆根结线虫。切片观察发现,其会阴花纹整体呈圆形至卵圆形,线纹较密且平滑,背弓较高,为方形或近圆形,无明显侧线。利用象耳豆根结线虫特异性引物进行PCR扩增,得到大小约236 bp的目的条带,说明所鉴定线虫为象耳豆根结线虫。系统发育树结果显示,所鉴定根结线虫与已知的不同地区象耳豆根结线虫聚为同一进化分支,进一步确定陕西省洛南县采集的根结线虫为象耳豆根结线虫。本文首次发现并报道了陕西省有象耳豆根结线虫为害,为该线虫的扩散及防治研究奠定了基础。     

Evaluation of chemical and integrated strategies as alternatives to methyl bromide for the control of root-knot nematodes in Greece

Current environmental awareness has led to a greater demand for alternative nematode control strategies. Three field experiments were established to compare management tactics on cucumber in commercial greenhouses naturally infested with root-knot nematodes (Meloidogyne spp). Cucumber rootstocks which have shown resistance to soil-borne diseases were tested to reveal any resistance/tolerance to root-knot nematodes, and integration of these rootstocks with nematicides was investigated. Metham-sodium and 1,3-dichloropropene (1,3-D) provided good control of nematode populations when their application was followed by the application of a non-fumigant nematicide such as cadusafos or oxamyl. Neither fumigant could provide season-long control of nematode populations, and a further application of cadusafos was required for satisfactory control. The efficacy of metham-sodium was significantly increased when injected into soil in comparison with its application through the drip irrigation system. The use of rootstocks resistant to soil-borne fungal pathogens used together with chemical means of nematode control provided promising results for their further use in integrated strategies as alternatives to methyl bromide. However, the latter was the superior treatment for the control of root-knot nematodes in soil infested with residues of galled roots. Dazomet, metham-sodium nor the non-fumigant nematicides oxamyl and fenamiphos could reduce nematode population as efficiently as methyl bromide. None of the chemicals tested except methyl bromide could enter galled roots and kill surviving nematodes.     

土壤熏蒸结合机械化深耕处理防治连作土壤西瓜根结线虫效果评价

为筛选防治西瓜根结线虫(Meloidogyne incognita)的安全、高效防治技术,本研究对浅耕、深耕、浅耕+棉隆、深耕+棉隆4种土壤连作障碍处理耕作机械化技术防治西瓜根结线虫的效果及对土壤微量元素的影响等进行了评价。结果表明,与对照普通耕作模式相比,4种处理均能显著降低土壤中西瓜根结线虫的数量,提高对根结线虫的防治效果,增加西瓜的产量。其中,以深耕+棉隆处理的防治效果和增产效果最好。深耕+棉隆处理可以增加交换性镁和有效硒的含量,对交换性钙和有效铜的含量没有显著影响。综合评价认为深耕+棉隆处理适于在西瓜根结线虫发生非常严重的地区推广应用,而对于根结线虫发生特别轻的地区,仅以浅耕处理就能有效控制其危害。本研究提供了一种耕作措施与化学农药熏蒸相结合防治根结线虫的新方法,对于减少化肥农药用量,保护农业生态环境安全具有重要意义。     

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.     

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。