Histological mechanisms of the resistance conferred by the Ma gene against Meloidogyne incognita in Prunus spp

The Ma gene from Myrobalan plum is a TNL gene that confers a high-level resistance to all root-knot nematodes of major economic importance, including Meloidogyne incognita, M. javanica, M. arenaria, and M. enterolobii. The nematode behavior in the roots and the corresponding histological mechanisms of the Ma resistance to M. incognita in the resistant (R) accessions of the plum 'P.2175' and the interspecific hybrid P.2175×almond-peach '35', carrying the Ma1 allele (Ma1/ma), were characterized in comparison with the susceptible (S) accessions in the plum 'P.2032' and the interspecific hybrid P.2175×almond-peach '253' (ma/ma). Second-stage juveniles (J2s) were inoculated in micropropagated plantlets grown in soil substrate under controlled conditions at 25°C. Nematodes penetrated both R and S plants preferentially along the apical zone or close to the young lateral buds and moved via similar routes. Then they migrated into the cortex downward in the direction of the apex and turned up in the meristematic apical region to colonize the differentiating stele. In R accessions, motile J2s neither swelled nor developed into J3s, and initiation of feeding sites was never observed. This complete absence of gall symptoms is associated with cell necroses and corresponding hypersensitive-like reaction (HLR) phenotypes occurring either in the stele or in the meristematic apical region or in the cortex. Nematode attacks often disorganized the meristematic apical tissues of R accessions, which induced the development of subterminal lateral roots replacing primary terminal apices and, thus, provided an active resistance reaction to HLR damage.     

中国小黑豆抗源对大豆孢囊线虫4号生理小种抗性机制的研究Ⅰ.抗源品种对大豆孢囊线虫侵染和发育的影响

 以鲁豆1号作感病对照,通过接种相同数量的卵和二龄幼虫并采用切顶水培技术研究我国筛选出的两个小黑豆抗源:灰皮支黑豆和元钵黑豆对大豆孢囊线虫4号生理小种侵染和发育的影响。结果表明,接种后24 h侵入大豆抗感品种根内的二龄幼虫数十分接近,差异不显著;接种后水培15~17 d,抗病品种根内的二、三龄幼虫数无论是单株平均值,还是所占百分数均极显著高于感病对照,而四龄幼虫、雌成虫和总成虫数正好与此相反。感病对照鲁豆1号根上二龄、三龄、四龄、雌成虫和总成虫数所占百分数为4.40%、10.20%、24.95%、29.35%和60.45%,而元钵黑豆和灰皮支黑豆根上各龄线虫的百分数分别为22.30%、26.50%、13.55%、3.80%、37.65%和24.30%、29.60%、15.05%、2.50%、31.15%。抗感品种根上线虫性比的差异极明显,抗病品种为10左右,而感病对照稍大于1;抗病品种根上线虫幼虫从二龄到三龄及从三龄到四龄阶段有较高的死亡率,而且从三龄到四龄阶段的死亡率高于从二龄到三龄阶段。     

New sources of resistance to Meloidogyne incognita race 3 in wild cotton accessions and histological characterization of the defence mechanisms

Accessions of Gossypium spp., some of them never previously tested, were evaluated for resistance to a local isolate of Meloidogyne incognita race 3 in greenhouse experiments. Nematode infection was characterized based on the galling and egg mass indexes and the reproduction factors (RF). Root‐knot nematode reproduction among the newly tested accessions varied from highly susceptible (AS0188, AS0189) to moderately resistant (MT123 no. 3), and some accessions showed highly reduced nematode reproduction (CIR1343, CIR1348, Fai Mui). Histological observations of two resistant accessions (G. barbadense CIR1348 and G. hirsutum TX‐25, respectively) showed that resistance occurs through a two‐stage mechanism in the first accession and through a single‐stage mechanism in the second. Parasitism is blocked early after second‐stage juvenile (J2) penetration or during its initial tissue migration (CIR1348) and the development of later‐stage juveniles into female adults is suppressed at a later stage (TX‐25 and CIR1348). Fluorescence and bright light microscopy showed that root cells surrounding nematodes exhibit a hypersensitivity‐like reaction, with the accumulation of presumably phenolic compounds and the presence of necrotic cells that limit the development of nematodes and the formation of giant cells. Underdeveloped giant cells with degenerated cytoplasmic content were found in small numbers in CIR1348 and in large numbers in TX‐25, along with deformed nematodes. The full characterization of the defence mechanisms of novel sources of resistance to the root‐knot nematode in cotton constitutes a first step towards their use in crop improvement.     

The development of juveniles of Heterodera schachtii in roots of resistant and susceptible genotypes of Sinapis alba,Brassica napus,Raphanus sativus and hybrids

The development ofHeterodera schachtii Schm. (beet cyst nematode, BCN) juveniles in roots of resistant and susceptible genotypes belonging to cruciferous crop species and hybrids was studied from 4 to 28 days after inoculation. No difference in root penetration by larvae was observed between resistant and susceptible plants.The development of nematodes in roots from resistant plants ofRaphanus sativus L., resistant xBrassicoraphanus Sageret and a resistant hybrid xBrassicoraphanus x Brassica napus L. was similar. BCN resistance in these three sources of plant material appeared to be related to an increased male:female nematode ratio as compared to the ratio found in susceptibleR. sativus plants.Also in resistant plants ofSinapis alba L. and a resistant intergeneric hybridS. alba x B. napus the increase in male:female nematode ratio, as compared to the ratio found for susceptibleS. alba cultivars and a susceptible intergeneric hybridS. alba x B. napus, seemed to be related with the observed resistance. In roots of the resistantS. alba and of a resistant hybridS. alba x B. napus, however, BCN resistance might also be due to a slower development of larvae and increased necrosis of root cells at the site of larval penetration.     

南方根结线虫Me3毒性与非毒性群体对寄主趋向性和侵染能力的比较

 探究南方根结线虫Me3毒性与非毒性群体对抗感寄主趋向性和侵染能力,为揭示毒性群体致病机理及防治根结线虫策略提供理论依据。使用以水琼脂为介质的研究方法,通过对比分析辣椒抗病品种HDA149和感病品种茄门根尖附近聚集的2龄幼虫(J2)数量,来揭示南方根结线虫对抗感辣椒品种根尖的趋向性效应,并利用实时荧光定量 PCR 检测侵入到辣椒根系的毒性与非毒性线虫数量,对其侵染能力进行比较。J2 趋向性试验结果显示,在相同的时间点,HDA149 和茄门辣椒根尖处附近聚集的毒性群体 J2 数量总是显著多于非毒性群体的 J2数量;J2 对抗感辣椒的选择性结果表明,不论是毒性群体还是非毒性群体的 J2,在相同的时间点,茄门根尖附近聚集的线虫数量显著多于HDA149根尖附近的线虫数量;荧光定量 PCR 检测线虫侵染结果显示,毒性群体 J2侵入到辣椒根系的数量相对非毒性群体的 J2 更多。总之,相比南方根结线虫Me3非毒性群体,毒性群体的 J2 对寄主根系有较强的趋向性,并且侵染效率更高;相比于抗性寄主,Me3毒性群体和非毒性群体的 J2 对感病寄主有更强的选择性。     

Comparative host suitability to Meloidogyne spp. and Pratylenchus vulnus in Myrobalan plum (Prunus cerasifera)

Nine Myrobalan plum clones ( Prunus cerasifera ) obtained from in vitro propagation were tested for host suitability to four root-knot nematode (RKN) isolates ( Meloidogyne incognita (2), M. javanica (1), and M. hispanica (1)) and one root-lesion nematode (RLN), Pratylenchus vulnus , isolate. The clones are characterized according to the Ma major resistance genes that control resistance to M. arenaria , M. incognita and M. javanica and are categorized into five resistant (R) and four host (H) clones to these RKN species. As expected, the clones ranged, regardless of the RKN species or isolate, into the same distinct R (P.2175, P.1079, P.2980, H.17 and H.21) and H (P.2794, H.18, H.23 and P.16.5) groups for RKN resistance. The P. vulnus tests showed that all the clones had higher final populations than initial populations ( P _f :  P _i > 1) and that P _f :  P _i ratios were equivalent in each RKN resistance group (R or H). Consequently, resistant alleles of RKN Ma genes in Myrobalan plum have no major effect on RLN multiplication. Our data must be taken into account for breeding strategies aimed at incorporating multiple resistance to both RKN and RLN in Prunus spp.     

酸黄瓜南方根结线虫病抗性的解剖学及其细胞学研究

为探明酸黄瓜南方根结线虫病抗性的内在机理,以抗病材料酸黄瓜与感病材料北京截头为试材,对南方根结线虫侵入与幼虫发育、根的解剖学及线虫侵入诱导形成的取食位点的细胞学结构进行了比较研究。结果表明,抗病材料酸黄瓜根系中线虫侵入率极显著低于感病材料北京截头(P0.01),酸黄瓜能够有效抵抗南方根结线虫的侵入;抗、感材料根系中雌雄虫个体比例分别为1∶12和1∶5(P0.01),抗性反应能够抑制线虫取食和幼虫发育;酸黄瓜根的解剖结构与普通栽培黄瓜相似,酸黄瓜的根不具有结构抗性;抗病反应中细胞发生过敏性坏死,感病反应中无此类现象发生。抗侵入、抑制取食和坏死反应是抗病材料酸黄瓜抗性反应的主要特征。     

几种除草剂对大豆孢囊线虫存活和孵化的影响

在实验室内寄主体外测定了8种大豆田常用除草剂对大豆孢囊线虫（SCN）(Heterodera glycines Ichinohe)2龄幼虫（J2）存活率及卵孵化的影响,同时测定了乙草胺和2,4滴丁酯+异丙草胺对温室和田间SCN繁殖的影响。结果表明,所有供试除草剂对大豆孢囊线虫J2均有不同程度的致死作用,其中以乙草胺、2,4滴丁酯+异丙草胺和嗪草酸甲酯处理效果最好,24 h死亡率分别达99.33%、99.33%和89.33%;乙草胺、2,4滴丁酯+异丙草胺、嗪草酸甲酯和精噁唑禾草灵处理7 d,J2的死亡率均达100%,精喹禾灵、精吡氟氯禾草灵和三氟羧草醚处理的死亡率分别为91.33%、81.33%和79.33%;所有除草剂对孢囊孵化都有较强的抑制作用,其中2,4滴丁酯+异丙草胺的抑制作用最强,孢囊孵化率仅为1.25%;乙草胺和2,4滴丁酯+异丙草胺对温室和田间SCN的繁殖均有较强的抑制作用,对大豆根系生长均无不良影响。不同除草剂对大豆种子萌发有一定影响。     

种子处理诱导大豆抗胞囊线虫病的生防细菌筛选与鉴定

国内研究了简单芽孢杆菌Bacillussimplex包衣处理大豆种子,诱导大豆植株抗胞囊线虫的侵染。采用温室盆栽试验,对研究室通过2年田间试验筛选出的3株生防细菌进行复筛,获得最优菌株Sneb545;为了阐明其作用方式,设计了裂根试验验证菌株Sneb545诱导大豆产生抗胞囊线虫的能力,并对菌株Sneb545进行种水平鉴定。结果表明,菌株Sneb545处理种子后可以诱导苗期大豆对第一代胞囊线虫产生明显的抗性,线虫入侵总数显著降低,较对照降低72．63％,胞囊抑制率达70．63％;裂根试验结果证明,菌株Sneb545能够诱导大豆对胞囊线虫产生很强的抗性,菌株Sneb545在挑战根系中接种后,应答根系中胞囊线虫入侵量降低51．27％,土壤中胞囊减少65．82％;经形态学特征、生理生化试验测定及16SrDNA序列同源性分析,确定该菌株为简单芽孢杆菌。     

Effects of fosthiazate and aldicarb on populations of plant-growth-promoting bacteria, root-lesion nematodes and bacteria-feeding nematodes in the root zone of potatoes

A 2-year study investigated the relationship between the nematicides aldicarb and fosthiazate and populations of plant growth-promoting (PGP) and plant-growth-inhibiting (PGI) bacteria, and root-lesion nematodes and bacteria-feeding nematodes in the root-zone soils of potatoes. Fewer ( P  < 0.05) bacterial genera and species were recovered from aldicarb-treated soils than from the fosthiazate and untreated soils but bacterial population densities were greatest in the aldicarb-treated soils. In potato plantlet bioassays using root-zone bacteria from the three soil sources, bacteria from the aldicarb-treated soils reduced ( P  < 0.01) the mean wet and dry weight of shoots and roots compared with those from the fosthiazate and untreated soils. In the field, fosthiazate (but not aldicarb) significantly increased tuber yields and reduced nematode population densities of Pratylenchus penetrans in roots and soil. Population densities of bacteria-feeding nematodes (primarily Diplogaster lheritieri ) were not affected by either nematicide. Aldicarb appeared to suppress the populations of plant-growth-promoting bacteria that contribute to enhanced growth in potatoes. This is attributed to the long-term use of aldicarb at the trial site, which may have encouraged the selection, or adaptation, of soil microorganisms that degrade carbamate pesticides but do not enhance potato growth.     

Interaction of Root-knot Nematodes (RKN) and the Bacterium Agrobacterium Tumefaciens in Roots of Prunus Cerasifera: Evidence of the Protective Effect of the Ma RKN Resistance Genes Against Expression of Crown Gall Symptoms

Agrobacterium tumefaciens (AT) is the causal agent of crown gall, a major problem in the family Rosaceae and particularly for Prunus spp. Crown gall symptoms result from the bacterial infection of the cells damaged mechanically at the collar or by root parasitic nematodes. Myrobalan plum (P. cerasifera) is susceptible to AT and is not a host for the root-knot nematode (RKN), M. hapla. Some clones of this plum carry single Ma resistance genes that control M. arenaria, M. incognita and M. javanica. The four above mentioned RKN and Myrobalan progenies segregating for Ma were used in experiments aimed at obtaining a better knowledge of the interaction between AT and RKN in relation to the RKN resistance genes. Prunus rooted cuttings, naturally infected with the bacterium were repotted, grown and inoculated individually with RKN. In a first experiment, Prunus plants were (i) either inoculated with 10,000 juveniles (J2s) of M. arenaria to provide a short inoculum pressure (SIP) or (ii) inoculated by association with one M. arenaria-galled tomato root system that produced a high and durable inoculum pressure of the same nematode species. Four months after RKN inoculation, plants were rated for nematode and bacterial root galling symptoms. RKN and AT galls were more numerous and more homogenous under DIP than under SIP. Nevertheless, for both inoculum regimes, AT galls were present in the RKN-susceptible clones (= carrying none of the Ma genes) and absent in the RKN-resistant clones. Subsequent experiments, conducted under DIP with M. arenaria, M. incognita, M. javanica and M. hapla, also showed, for the three first species, the presence of AT galls only in RKN-susceptible clones whereas Prunus plants inoculated with M. hapla and nematode-free controls were free of AT galls. Consequently RKN act as a wound agent in the AT infection process of Myrobalan plum only when the plant develops a compatible reaction (i.e. when it lacks the Ma resistance genes). Considering that J2s do penetrate the roots of resistant plants, the absence of crown gall symptoms on this material even under durable inoculum pressure strengthens the hypothesis that this nematode stage has a very weak effect on plant cells during the infection process. This is the first evidence of the protective effect of a RKN resistance gene against the expression of root crown gall consecutive to RKN infection. The protective effect of Ma and presumably of other RKN resistance genes against AT is a strong argument for their introgression into Prunus and other Rosaceae or bacterium-susceptible crops.     

小麦禾谷孢囊线虫寄生范围的研究

经测试表明,禾谷孢囊线虫(Heterodera avenae)对长江中游地区栽种的小麦、裸大麦、米大麦、家燕麦、野燕麦、黑麦草、鹅冠草、苇状羊茅、球茎草芦和鸭茅均能侵染,这些植物是该线虫的良好寄主,但感染率差异不显著。该线虫能侵染玉米,但很难完成生活史,不侵染供试的红三叶草和紫苜蓿2种非禾本科牧草。在不同的寄主根内,线虫发育速度有差异,单位重量根内虫口数亦有异,黑麦草内最多,鲜根有线虫4.45条/g,鸭茅最少为1.26条/g。     

Effects of three microbial broth cultures and an organic amendment on growth and populations of free living and plant-parasitic nematodes on banana

The effect of 24 treatment combinations of cultures of Streptomyces costaricanus sp. nov. (ATCC55274), Bacillus thuringiensis (ATCC55273) and a strain of Paecilomyces marquandii, nematicide (cadusaphos), and/or wheat mash on growth and response of potted banana plants (Musa AAA) and populations of Radopholus similis, Helicotylenchus multicinctus and free living nematodes were studied in Río Frío, Costa Rica. The best plant responses (height, leaf numbers, healthy root weight), lowest numbers of plant parasitic nematodes and highest numbers of free living nematodes were observed for treatments containing wheat as a component. Two treatments, viz. wheat + Streptomyces costaricanus (200-ml culture) and wheat + P. marquandii (200-ml culture), gave the overall best results. Numbers of free living nematodes increased up to 1500-fold only for treatments containing wheat. Significant positive correlations existed between numbers of free living nematodes and shoot weight, healthy root biomass, plant height, and leaf numbers. Non-wheat treatments, including nematicide only, gave the poorest responses in general. Observations of nematodes sampled 50 days following planting in wheat-containing treatments showed most of the free-living nematodes ( 90%) to be infected by nematophagous fungi (species not recorded). The results show that an organic amendment to soil, with or without a microbial component, can be an effective inducer of processes that regulate plant-parasitic nematode populations in soil.     

安徽省潜山县栝蒌根结线虫发生危害及大田药效试验

为了有效防治栝蒌根结线虫，调查了安徽省潜山县栝蒌根结线虫及其发生，并分析了栝蒌根围土壤线虫的组成。通过线虫形态学鉴定，认为潜山栝蒌上的根结线虫为Meloidogyne incognita。栝萎根围土壤中有口针线虫占调查总量的50．7％，根结线虫2龄幼虫（J2）占31．8％。对当年栝萎J2在土壤表、中、下层的分布和年发生调查结果表明，J2在各层的分布量因月份不同而不同，并分别于3月初到9月中旬问出现2次虫口高峰；防治试验结果表明，除有机肥外，各试验小区在施药后49天J2虫口相对减退率在89．6％以上；施药后124天，克线丹和1．8％阿维菌素处理的小区增果率为250％～480％，收到很好的防效。     

Interactions Among a Soil Organic Amendment, Nematodes, and the Nematode-Trapping Fungus Dactylellina candidum

ABSTRACT When alfalfa leaves (Medicago sativa) are added to soil, both the nematode-trapping fungus Dactylellina candidum and microbivorous nematodes increase. To determine whether the response of the fungus to alfalfa depends on consumption of bacterivorous and fungivorous nematodes, soil microcosm experiments were performed. D. candidum did not increase if alfalfa leaves were added to soil lacking nematodes, but did increase if nematodes were added to soil lacking alfalfa leaves. Although these results indicate that the response of D. candidum to alfalfa depends on nematodes, D. candidum and microbivorous nematodes did not exhibit classical predator-prey dynamics (i.e., D. candidum seldom reduced numbers of resident nematodes and, after initially increasing in alfalfa amended soil, numbers of D. candidum then decreased, whereas numbers of nematodes continued to increase). Fungivorous nematodes were abun dant in alfalfa-amended soil, and their potential to suppress trapping fungi requires more research.     

Differential effect of nematicide treatments on tuber yields in early- and late-maturing potato cultivars

A 3-year field study examined the effects of 1,3-dichloropropene or oxamyl on tuber yields in four early- and five late-maturing potato cultivars. The nematicide treatments increased total tuber yield by ≈ 12% for early-maturing cultivars, but by less than 2% for the late-maturing cultivars. The treatments reduced the numbers of root lesion nematodes (primarily Pratylenchus penetrans ), which were the dominant plant parasitic nematodes at the site. Covariance analysis indicated that treatment effects on total tuber yield were no longer significant after adjusting for root lesion nematodes in soil at harvest, confirming that these nematodes had a direct effect on the host. As expected, there were significant inverse relationships ( P  = 0·05) between total tuber yields and numbers of root lesion nematodes in soil and in roots. However, the application of nematicides in late-maturing cultivars was found to be of no practical value. Crop production systems designed to reduce or optimize pesticide applications can form one criterion in the development of more environmentally sensitive management strategies. The merit of utilizing chemicals for root lesion nematode control are considered with regard to cultivar maturity.     

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。     

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。     

燕麦孢囊线虫在河北冬麦区的种群动态

为明确河北省燕麦孢囊线虫Heterodera avenae在自然环境下的侵染与发育特点,于2009-2012年分别采用漂浮法、浅盘法和酸性品红染色法在3个不同区域对土壤中孢囊和2龄幼虫(J2)以及根系内线虫进行了系统调查,并对孢囊内卵的发育动态进行检测.在土壤中除6月上中旬未检测到J2外,周年均分离到J2.冬前J2出现小高峰,种群密度为12.3 ～18.6条/100mL土样;在4月上中旬J2大量发生,种群密度为52 ～ 65条/100 mL土样.冬前J2侵入小麦后能够发育至3龄幼虫,3龄幼虫发生高峰在4月下旬至5月上旬,4龄幼虫的发生高峰在5月中下旬,白雌虫形成高峰期在5月下旬,且1年后孢囊内卵孵化率达到86.5％.研究表明,燕麦孢囊线虫在河北省小麦上1年发生1代,关键侵染期在3月下旬至4月中旬.     

Parasitism of <Emphasis Type="Italic">Trichoderma</Emphasis> on <Emphasis Type="Italic">Meloidogyne javanica</Emphasis> and role of the gelatinous matrix

Trichoderma (T. asperellum-203, 44 and GH11; T. atroviride-IMI 206040 and T. harzianum-248) parasitism on Meloidogyne javanica life stages was examined in vitro. Conidium attachment and parasitism differed beween the fungi. Egg masses, their derived eggs and second-stage juveniles (J2) were parasitized by Trichoderma asperellum-203, 44, and T. atroviride following conidium attachment. Trichoderma asperellum-GH11 attached to the nematodes but exhibited reduced penetration, whereas growth of T. harzianum-248 attached to egg masses was inhibited. Only a few conidia of the different fungi were attached to eggs and J2s without gelatinous matrix; the eggs were penetrated and parasitized by few hyphae, while J2s were rarely parasitized by the fungi. The gelatinous matrix specifically induced J2 immobilization by T. asperellum-203, 44 and T. atroviride metabolites that immobilized the J2s. A constitutive-GFP-expressing T. asperellum-203 construct was used to visualize fungal penetration of the nematodes. Scanning electron microscopy revealed the formation of coiling and appressorium-like structures upon attachment and parasitism by T. asperellum-203 and T. atroviride. Gelatinous matrix agglutinated T. asperellum-203 and T. atroviride conidia, a process that was Ca²⁺-dependent. Conidium agglutination was inhibited by carbohydrates, including fucose, as was conidium attachment to the nematodes. All but T. harzianum could grow on the gelatinous matrix, which enhanced conidium germination. A biomimetic system based on gelatinous-matrix-coated nylon fibers demonstrated the role of the matrix in parasitism: T. asperellum-203 and T. atroviride conidia attached specifically to the gelatinous-matrix-coated fibers and parasitic growth patterns, such as coiling, branching and appressoria-like structures, were induced in both fungi, similarly to those observed during nematode parasitism. All Trichoderma isolates exhibited nematode biocontrol activity in pot experiments with tomato plants. Parasitic interactions were demonstrated in planta: females and egg masses dissected from tomato roots grown in T. asperellum-203-treated soil were examined and found to be parasitized by the fungus. This study demonstrates biocontrol activities of Trichoderma isolates and their parasitic capabilities on M. javanica, elucidating the importance of the gelatinous matrix in the fungal parasitism.