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1.
湖南柑橘根结线虫种类鉴定及特异性PCR检测   总被引:1,自引:0,他引:1  
根结线虫病是严重危害湖南柑橘生产的主要病害,快速准确地进行病原线虫鉴定,从而制定针对性的防治措施,对柑橘产业的稳定发展至关重要。运用形态学和分子生物学技术对湖南永州地区柑橘根结线虫进行病原种类鉴定,确定其为番禺根结线虫Meloidogyne panyuensis。通过引物设计与筛选,建立了番禺根结线虫特异性PCR检测技术。结果表明,该检测方法特异性好,灵敏度高,操作简单,能有效地从多种根结线虫中特异性检测出番禺根结线虫,为柑橘病原线虫的快速检测鉴定提供技术支撑。  相似文献   

2.
The host suitability of commercial Vitis rootstocks commonly used in Spain (161‐49C, 41B, 1103P, 110R, 140Ru and SO4) to root‐knot nematodes (Meloidogyne arenaria, M. incognita, M. javanica) and Xiphinema index, and damage caused by nematode infection were determined under controlled conditions. The three root‐knot nematodes reproduced with a rate higher than one in all rootstocks, indicating that they are suitable hosts for these nematodes. Growth of rootstocks infected with the root‐knot nematodes was less vigorous than that of nematode‐uninfected controls in the majority of the rootstocks studied. Root infection resulted in moderate to severe root galling in all rootstocks. The shoot and main stem diameters appeared to be the most sensitive variables of damage caused by infection by Meloidogyne spp., with reduction rates from 36% and 53% in 161‐49C to 57% and 66% in 140Ru, respectively. The shoot height was not significantly affected by the root‐knot nematodes and the root fresh weight generally increased as a consequence of intensive galling. The nematode X. index caused significant root damage with a reproduction factor higher than one in all rootstocks. However, reproduction factor was significantly influenced by the rootstock and significantly decreased by about 12‐fold (5·7 to 18·1‐fold) with the increase in inoculum density from 100 to 1000 nematodes per plant. The root dry weight was reduced by X. index infections, and was the plant growth variable most affected by the nematode infection in all rootstocks at both inoculum densities. Meloidogyne arenaria, M. incognita, M. javanica and X. index, prevalent in many world vineyards, are all shown to have a damaging effect on the six tested rootstocks.  相似文献   

3.
4.
广西香蕉植物线虫病发生情况调查   总被引:1,自引:0,他引:1  
作者于2009-2010年,对广西香蕉线虫病发生情况进行了实地调查,分别采集根际土壤和根系样本共253份,调查结果表明:广西香蕉主要有害线虫有根结线虫、矮化线虫、短体线虫、肾状线虫、螺旋线虫、滑刃线虫、纽带线虫、垫刃线虫和小环线虫,其中根结线虫发生最普遍也最严重,根结病指最高达60,土壤根结线虫虫口密度最高达307头/100 mL土。〖JP〗  相似文献   

5.
The effects were investigated, under controlled conditions, of single and joint inoculation of olive planting stocks cvs Arbequina and Picual with the arbuscular mycorrhizal fungi (AMF) Glomus intraradices , Glomus mosseae or Glomus viscosum , and the root-knot nematodes Meloidogyne incognita and Meloidogyne javanica , on plant performance and nematode infection. Establishment of the fungal symbiosis significantly increased growth of olive plants by 88·9% within a range of 11·9–214·0%, irrespective of olive cultivar, plant age and infection by M. incognita or M. javanica . In plants free from AMF, infection by Meloidogyne spp. significantly reduced the plant main stem diameter by 22·8–38·6%, irrespective of cultivar and plant age. Establishment of AMF in olive plants significantly reduced severity of root galling by 6·3–36·8% as well as reproduction of both Meloidogyne spp. by 11·8–35·7%, indicating a protective effect against parasitism by root-knot nematodes. Infection by the nematodes influenced root colonization by AMF, but the net effect depended on the AMF isolate–olive cultivar combination. It is concluded that prior inoculation of olive plants with AMF may contribute to improving the health status and vigour of cvs Arbequina and Picual planting stocks during nursery propagation.  相似文献   

6.

Effects of triple super phosphate (TSP) and single super phosphate (SSP) fertilizers on efficacy of a Glomus sp. (isolate KS 14) against Meloidogyne hapla were determined. The fertilizers were applied at 150 and 300 kg ha -1 at the time of fungus inoculation. Two months later, plants were inoculated with the nematodes. Plant growth and nematode disease parameters were determined 2 months after nematode inoculation. The fertilizers at both levels improved plant growth in all treatments. In general, the fungus improved plant growth on its own or in the presence of nematodes, but not in the presence of fertilizers. Both fertilizers at both levels were more effective in improving plant growth than the fungus. The fungus showed sensitivity to inorganic P fertilizers in that the fertilizers significantly reduced fungal root colonization and its pyrethrum growth stimulative effects. The fungus suppressed nematode disease severity unlike the fertilizers. The suppressive effects of the fungus on the nematodes were in most cases reduced by the fertilizers. The nematodes, unlike the fertilizers, did not have any significant effects on root colonization by the fungus or on its ability to improve pyrethrum growth. The presence of nematodes in fertilizer or fertilizer-fungus-treated plants, however, significantly reduced pyrethrum growth.  相似文献   

7.
Some aspects of the interaction of the bacterial parasite Pasteuria penetrans and the root-knot nematode ( Meloidogyne spp.) were investigated in laboratory and pot experiments. The variable spore attachment on juveniles exposed to water suspensions of the bacterium is probably attributed to differential susceptibility of biotypes within a heterogeneous Meloidogyne population. The relationship between spore concentration and attachment level is not linear over a range of spore dosages, indicating that even at very high spore concentrations the number of spores capable of attachment may not be present in excess and it is difficult to ensure sufficient numbers of spores to ensure infection will attach to all nematodes. Attempts to apply the bacterium in conditions such as might occur in seedbeds did not suppress nematode multiplication after transplanting in nematode-infested soil, indicating that the only effective application method is a thorough spore distribution in the planting sites. Two major constraints were revealed: high levels of spore attachment to juveniles does not always guarantee a significant reduction of egg laying and this is greatly influenced by the Meloidogyne biotype. Furthermore, the cumulative effect of the parasite in reducing Meloidogyne populations over several crop cycles was less than expected as the bacterium reduced intra-specific competition for the food supply and the less damaged root enabled many nematodes to survive.  相似文献   

8.
Abstract

In a survey of plant parasitic nematodes associated with or affecting rice throughout Nigeria, some important nematode pests, especially the white tip disease nematode, Aphelenchoides besseyi and the rice root nematodes Hirschmanniella spinicaudata and H. oryzae were identified from seed, soil and root samples from swamp rice fields respectively. The sugarcane cyst nematode, Heterodera sacchari occurred in swamp rice fields only around the major sugarcane estates in Nigeria. The root‐knot Meloidogyne incognita and the root lesion nematode, Pratylenchus brachyurus were also encountered in upland (rainfed) rice fields. The white tip disease nematode, A. besseyi occurred at low levels in soils and rice seeds throughout the country. High population levels of H. spinicaudata and H. oryzae were encountered especially in areas where monoculture of rice is practised. General chlorosis, poor tillering and significantly reduced yield have been observed due to H. spinicaudata. Rice plants attacked by H. sacchari also showed intense chlorosis, delayed and reduced tillering and reduced grain yield. The roots of attacked plants were twiggy, very necrotic and blackened. The root‐knot M. incognita and the root lesion nematodes P. brachyurus have both been observed to reduce rice yields. Rice cultivars screened for reactions to the nematodes showed varying degrees of susceptibilities. Some varieties were however resistant to the root‐knot nematode, M. incognita.  相似文献   

9.
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。  相似文献   

10.
根结线虫食道腺细胞表达的基因及其应用潜力   总被引:4,自引:0,他引:4  
根结线虫是国际公认的最为重要的植物病原线虫,研究其食道腺细胞表达的基因是了解其寄生性和致病性的基础。近年来国际上已从根结线虫食道腺细胞分离基因22个,其基因产物主要包括β 1,4内切葡聚糖酶、果胶酸裂解酶、分支酸变位酶、钙网蛋白、类毒液过敏蛋白等。本文对上述工作的研究进展作简要评述,并对今后的应用潜力进行了讨论。  相似文献   

11.
Root-knot nematodes (RKN) are obligate endoparasites that severely damage the host root system. Nutrient and water uptake are substantially reduced in infested plants, resulting into altered physiological processes and reduced plant growth. The effect of nematode infestation on the morphological changes of roots and subsequent physiological plant responses of infested tomatoes with the RKN Meloidogyne ethiopica was studied in a pot experiment. Plants were infested with two inoculum densities (10 or 50 eggs per cm3 substrate) and its effect was evaluated 74 and 102 days post inoculation (DPI). Morphological changes and root growth was determined by analysing scanned images of the whole root system. Nematode infestation reduced the portion of fine roots and increased that of coarse roots due to gall formation. Fine roots of non-infested control plants represented around 51% of the area of the whole root system at 74 and 102 DPI. In comparison to controls, plants inoculated with low and high nematode density had 2.1 and 3.2-times lower surface area of fine roots at 102 DPI. Root analyses revealed that plants had a very limited ability to mitigate the effects of the root-knot nematodes infestation by altering root growth. Root galls had a major influence on the hydraulic conductivity of the root system, which was significantly reduced. The low leaf water potential of infested plants coincided with decreased stomatal conductivity, transpiration and photosynthesis. The latter two were reduced by 60–70% when compared to non-infested control plants.  相似文献   

12.
番茄抗性品种与黄瓜轮作对根结线虫的防治作用   总被引:6,自引:0,他引:6       下载免费PDF全文
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。  相似文献   

13.
Meloidogyne ethiopica is one of the most important plant-parasitic nematodes affecting vines in Chile and is very aggressive and difficult to control. This study evaluated 16 strains of rhizobacteria, originally isolated from roots of grapevines, for their effects on parasitism and nematode damage to potted vine plants. The antagonistic effect of rhizobacteria was assessed by treating 2-month-old plants of cv. Chardonnay in 3-l pots with a suspension containing 1?×?106?cfu?ml?1 of the bacteria and 1,000 nematode eggs. After 6?months of growth, the plants were cut and root and canopy weights, nematode populations and root damage determined. The effect of rhizobacterial culture filtrate on hatching of nematode eggs was also assessed in vitro. Seven strains of rhizobacteria proved effective in inhibiting damage or reproduction of the nematode. These were strains of Serratia marcescens, Comamonas acidovorans, Pantoea agglomerans, Sphingobacterium spiritivorum, Bacillus mycoides, Alcaligenes piechaudii and Serratia plymuthica. A further three strains, of Bacillus megaterium, P. agglomerans and Pseudomonas savastanoi, significantly increased root weight, but did not decrease nematode damage or population density. The supernatant of all strains significantly decreased hatching of juvenile nematodes after 24?h of immersion, with isolates of P. putida and B. megaterium being the most effective.  相似文献   

14.
The effects on white clover ( Trifolium repens ) of different combinations of the nematodes Meloidogyne trifoliophila , Helicotylenchus dihystera and Heterodera trifolii and nine stolon-infecting and three root-infecting fungi were studied in a glasshouse experiment. The presence of the fungus Phytophthora megasperma alone increased ( P  < 0·001) root-rot severity and reduced ( P  < 0·001) plant growth. Other species combinations, such as Phoma nebulosa and Alternaria alternata , interacted and increased root-rot severity. Combinations of P. megasperma with Pythium irregulare , and P. nebulosa with Phoma medicaginis or A. alternata , increased M. trifoliophila populations. Several other fungi ( P. irregulare , P. nebulosa , Colletotrichum coccodes , Macrophomina phaseolina , P. medicaginis and Phoma sp.) interacted with the nematode M. trifoliophila causing severe root-knot symptoms. The results indicated that fungi and nematodes interacted to cause root and stolon rot and reduced yields, and that poor persistence of white clover in pastures is likely to be a problem with a complex etiology.  相似文献   

15.
牛蒡上发生的根结线虫种类鉴定   总被引:1,自引:0,他引:1  
2007~2009年,对我国牛蒡主产区的牛蒡及其根际土壤中的植物寄生线虫进行调查研究,发现根结线虫危害最为严重。根据根结线虫的形态学特征和分子生物学检测方法对其进行鉴定,结果表明,我国牛蒡主产区根结线虫种类为北方根结线虫(Meloidogyne hapla)。  相似文献   

16.

Two arbuscular mycorrhiza fungi (AMF) isolated from a pyrethrum-growing region in Kenya were screened for efficacy against a nematode, Meloidogyne hapla, in greenhouses. The fungi were identified at INVAM (International Culture Collection of Vesicular Arbuscular Mycorrhizal Fungi) as Glomus etunicatum (Isolate KS18) and Glomus sp. (Isolate KS14). Isolate KS14 (Glomus sp.) significantly suppressed nematode population, growth and development by up to 54%, egg production by up to 75% and disease severity by up to 71%. Glomus etunicatum (Isolate KS18) suppressed nematode growth and development by up to 50%, egg production by up to 75% and disease severity by up to 57%. In addition, G. etunicatum and Isolate KS14, significantly improved top dry biomass of pyrethrum by up to 33% and 47%, respectively. Glomus etunicatum and M. hapla were mutually inhibitory as root colonization by G. etunicatum was significantly reduced (up to 24%) by the presence of the nematode. The presence of the nematodes, on the other hand, did not significantly affect root colonization by Isolate KS14.  相似文献   

17.
宁夏葡萄苗圃根结线虫病发病症状、为害程度及种类   总被引:2,自引:0,他引:2  
为有效防治葡萄苗圃根结线虫病,采用拔根百分法和直接解剖法调查宁夏永宁县玉泉营镇葡萄苗圃葡萄苗木根结线虫病的发病症状、为害程度,并通过形态学和分子生物学对其种类进行鉴定。结果表明:15个葡萄品种的病害症状之间有一定差异。除抗砧3号外,其余14个葡萄品种均受根结线虫侵染,且不同葡萄品种受根结线虫为害的严重度差异明显,其中西拉、红芭拉蒂、爱神玫瑰、阳光玫瑰、马瑟兰、贝达和黑比诺上根结线虫病较严重,病情指数介于51.67~78.33之间,大青的病情指数最低,为21.67。不同葡萄品种的每根段雌成虫数量之间、每根段根结数量之间差异明显,其中葡萄品种贝达的每根段雌成虫数量和每根段根结数量最多,分别为12.47条和4.27个,葡萄品种黑比诺的每根段雌成虫数量和每根段根结数量较少,分别为3.60条和1.73个;每根段雌成虫数量随着每根段根结数量的增加而增加。根据根结线虫2龄幼虫、雌成虫和会阴花纹的形态学特征及分子生物学鉴定结果确定为害葡萄苗圃的根结线虫主要为南方根结线虫Meloidogyne incognita和花生根结线虫M. arenaria。除抗砧3号外,其它14个葡萄品种均不同程度的感染了南方根结线虫和花生根结线虫,且所有葡萄品种感染南方根结线虫的比例均较高。  相似文献   

18.
The nematicidal effect of soil amendments with dry top and root material from Medicago sativa and/or Medicago arborea was evaluated on the root-knot nematode Meloidogyne incognita and on the cyst nematode Globodera rostochiensis in potting mixes. All amendments suppressed root and soil population densities of both nematode species compared to non-treated and chemical controls. The suppressiveness of M. sativa differed between top and root material and among the amendment rates. In field conditions soil amendments with 20 or 40 t ha−1 of a pelleted M. sativa meal increased tomato crop yield and reduced soil population densities and root galling by M. incognita. It is suggested that saponins were at least partly responsible for the nematicidal activity.  相似文献   

19.
The effects of root‐knot nematodes on black root rot of watermelon and bottle gourd were studied using field surveys and co‐inoculation tests with Meloidogyne incognita (southern root‐knot nematode) and Diaporthe sclerotioides. The results of the field survey suggested that root‐knot nematodes had little effect on either the severity of black root rot or infection with D. sclerotioides. None of the three fields showed a significant positive correlation between disease severity and nematode gall index, with low correlation coefficients. Co‐inoculation experiments under controlled conditions found no significant effect of root‐knot nematodes on black root rot of watermelon and bottle gourd based on area under disease progress curves (AUDPC). These results were supported by the quantities of DNA of the two agents in root tissues because no significant difference was found between dual‐ and single‐inoculation treatments with M. incognita and/or D. sclerotioides. These findings suggest that root‐knot nematodes probably do not affect the infection of watermelon or bottle gourd roots by D. sclerotioides or the incidence of black root rot in these crops caused by this fungus.  相似文献   

20.
Pathozone dynamics were derived for approx. 50 Meloidogyne incognita juveniles infecting a single root of tomato under controlled conditions from a point source of inoculum and described using simple, non-linear models. The pathozone decayed sigmoidally with distance, but increased over time as progressively more nematodes were able to infect the root. Despite the reported ability of M. incognita juveniles to travel up to 50 cm in some conditions, the maximum width of the pathozone for a single tomato root was estimated as 18·1 mm. It is conjectured that this was because of (i) diffusion from a point source of inoculum, (ii) a small infection court (a single root tip) and (iii) the limited life span of the nematode. A second experiment was used to assess the effect of the nematophagous fungus Pochonia chlamydosporia on the pathozone dynamics of the nematode. This fungus is known to produce nematicidal products in vitro , which may affect invasion of roots by the free-living nematode. To examine the possibility of a change in the position of the site of infection, changes in the probability of gall formation along the root length were also examined. In the absence of P. chlamydosporia , the pathozone dynamics of M. incognita were very similar to those of the first experiment. It was shown that P. chlamydosporia did not significantly affect the pathozone dynamics of M. incognita nor the site of gall formation, which appear to have little importance for the role of the fungus as a biological control agent.  相似文献   

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