Mitochondrial DNA variation of the dog hookworm Ancylostoma caninum in Brazilian populations     

Miranda RR  Tennessen JA  Blouin MS  Rabelo EM 《Veterinary parasitology》2008,151(1):61-67

The mitochondrial cytochrome oxidase I gene was partially sequenced for 164 Ancylostoma caninum individuals, originating from five different localities in Brazil, with the aim of describing the genetic diversity and genetic structure of Brazilian hookworm populations. Allelic and nucleotide diversity were moderate (overall h=0.88 and pi=0.016) and were similar among cities. There was moderate genetic differentiation among the populations sampled (approximately Phi(ST)=0.12) and a weak but nonsignificant correlation between geographical and genetic distance. This genetic structure was similar to that observed among populations of the human hookworm, Necator americanus, but distinct from that typically found in trichostrongylid nematode parasites of livestock. Thus, a pattern of different genetic structures among different groups of nematodes is emerging. We also observed a few individuals that had a highly divergent mtDNA sequence (almost 7% sequence divergence from the other sequences). These results in combination with data from other studies suggest that A. caninum populations worldwide consist of a mix of previously differentiated populations, or perhaps even cryptic species. This study contributes to the knowledge of genetic structure and diversity of hookworms, which in turn will be useful in developing methods for their control.  相似文献   

前茬作物对番茄根接线虫和枯萎病发生的影响     

冯明祥  王佩圣  姜瑞德  王继青  张涛  程星 《长江蔬菜》2008,(16)

前茬作物无论种植芹菜还是种植番茄,本茬作物(番茄)根结线虫病发病率无显著差异,但发病程度差异显著,种植芹菜的大棚,根结线虫病发生明显较轻;番茄枯萎病的发生与根结线虫有同样趋势。说明番茄与芹菜轮作,虽然不能根除根结线虫病的发生,但能明显减轻根结线虫和枯萎病的为害。  相似文献   

Relationships among peripheral eosinophilia, eosinophil peroxidase activity, interleukin-5 concentration and faecal nematode egg count during natural, mixed gastrointestinal nematode infection     

M. Doligalska  B. Moskwa  M. J. Stear 《Veterinary immunology and immunopathology》1999,70(3-4):299-308

A longitudinal study of sheep, naturally infected with gastrointestinal helminths, was carried out to quantify the relationships among eosinophilia, eosinophil peroxidase activity, interleukin-5 level and faecal egg counts. Faecal egg counts, peripheral eosinophilia and peroxidase activity per eosinophil were moderately repeatable but interleukin-5 concentrations had a remarkably high repeatability. Animals with higher concentrations of interleukin-5 had greater peripheral eosinophilia and those animals with higher numbers of eosinophils had lower faecal egg counts. These associations were statistically significant but quite weak. Variation in interleukin-5 levels does not appear to be responsible for most of the variation in eosinophil responses in outbred sheep.  相似文献   

萝卜抗根线虫基因导入油菜的研究   总被引：2，自引：0，他引：2  

潘大仁  W Friedt 《中国油料作物学报》1999,21(3):6-9

甘蓝型油菜与萝卜的属间不育杂种（ACR）经0．1％秋水仙素溶液处理杂种小苗,使杂种小苗的染色体加倍产生可育株,获得了31％可育的异源倍性植株。再用甘蓝型油菜与之回交,应用胚胎挽救技术产生了133株回交后代（BC1）的杂种株。从这些杂种株中筛选出部分抗线虫性强的杂交后代,证明通过染色体工程可以将萝卜中抗线虫的基因转移到甘蓝型油菜中。  相似文献   

Nematode resistance in bananas: screening results on some wild and cultivated accessions of Musa spp.     

P. Quénéhervé  C. Valette  P. Topart  H. Tezenas du Montcel  F. Salmon 《Euphytica》2009,165(1):123-136

Bananas cultivated for export all belong to Cavendish cultivars and are all recognized as very susceptible to nematodes, particularly to the burrowing nematode Radopholus similis and the lesion nematode Pratylenchus coffeae. Even if there have been many changes in the management of banana nematodes in large commercial banana plantations, chemical control still remains most often the last resort method to manage the nematodes, although the number of registered products is definitely declining. Therefore, nematode control though genetic improvement is gaining new interest worldwide. In this study, 55 banana accessions mostly diploids from the Musa acuminata genome group (AA) but including some triploid accessions (AAA), some diploids of the Musa balbisiana genome group (BB) and some interspecific hybrids (AAB, AB) were evaluated for resistance to four nematode species R. similis, P. coffeae, Meloidogyne incognita and M. arenaria. These experiments were conducted in a growth chamber under controlled conditions. All banana accessions were susceptible to nematode species, although many different levels of susceptibility were detected. This study confirmed the good resistance status to R. similis of some cultivars from the Pisang jari buaya and Pisang batuau subgroups and the partial resistance of 17 diploid accessions significantly different from the susceptible reference cv. Grande Naine. This study also showed that 12 diploid accessions exhibited a partial resistance to P. coffeae, including some usual or potential genitors belonging to the wild diploids subspecies burmannica (cvs. Long Tavoy 1 and 2) and burmannicoides (cv. Calcutta 4). No source of resistance to Meloidogyne spp. was found. These screening results, combining for the first time four nematode species, are discussed within the scope of banana breeding in order to produce parental diploid lines with single or combined nematode resistances and further develop triploids that can substitute existing susceptible commercial cultivars.  相似文献   

Suitability of weed species prevailing in Spanish vineyards as hosts for root-knot nematodes     

P. Castillo  H. F. Rapoport  J. E. Palomares Rius  R. M. Jiménez Díaz 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(1):43-51

Commercial vineyards in southern Spain were surveyed and sampled during October to December 2004 to determine the extent to which common weeds present were suitable hosts of root-knot nematodes infesting soils of those vineyards. Seven weed species commonly growing in grapevine soils in southern Spain were found infected by either Meloidogyne incognita or M. javanica: Amaranthus retroflexus (redroot pigweed), Anchusa azurea (ox-tongue), Chenopodium album (goosefoot), Erodium moschatum (musk stork’s bill), Malva rotundifolia (low mallow), Sinapis alba (white mustard), and Solanum nigrum (black nightshade). The host suitability of the weeds to root-knot nematodes was evaluated on the basis of root galling severity and nematode population densities in soil and roots. Also, the host–parasite relationship in these naturally Meloidogyne-infected weeds was examined. All the weed species in the study were considered suitable hosts for M. incognita and M. javanica because: (a) high Meloidogyne spp. populations occurred in roots and surrounding soil of the weed species; (b) the severity of root galling was high, and (c) well-established permanent feeding sites were observed in the histopathological studies of infected root tissues. In addition, this study presents the first reports of S. alba and A. azurea as hosts for M. incognita, and of E. moschatum as a new host for M. javanica, thus increasing the list of reported weed hosts for Meloidogyne spp. These results indicate that noticeable population densities of M. incognita and M. javanica can be maintained or increased in these weeds, at population levels higher than those previously reported for the same nematodes infecting grapevine roots. The weeds infesting vineyards thus represent an important source of inoculum of Meloidogyne spp., and furthermore may act as reservoirs of these nematodes which can be disseminated within or among vineyards by agricultural operations.  相似文献   

Assessment of nematicidal properties and phytochemical screening of neem seed formulations using Radopholus similis, parasitic nematode of plantain in Cameroon     

P. Kosma  Z. Ambang  B.A.D. BegoudeG.M. Ten Hoopen  J. KuateA. Akoa 《Crop Protection》2011,30(6):733-738

Phytoparasitic nematodes of banana and plantain make one of the major constraints to sustainable banana and plantain production. The burrowing nematode, Radopholus similis, common in Cameroon is of particular importance where most smallholder farmers are unaware of this “hidden enemy”. In intensive plantain plantations, nematicides are often used as a primary means of control. Despite their efficacy, chemical pesticides are harmful to the environment and human health. The objective of this study was to assess the nematicidal properties of four neem seed formulations (raw neem seed powder (NSP); organic, watery and essential oil extracts) and to determine the phytochemical properties of these extracts. Alkaloids, saponins, triterpens and steroids were found in all three extracts, tannins in the organic and essential oils extracts and phenols only in the essential oils extract. Using five different concentrations of each of the three extracts as well as NSP, the nematicidal properties of all four formulations was confirmed. The NSP killed 100% of all nematodes at the lowest concentration tested, 10 μg ml⁻¹, after 48 h. The in vivo test using two plantain varieties, Essong and Big Ebanga showed that all neem seed formulations increased plant growth and reduced nematode populations significantly when compared with the control. Since NSP seems to perform as well or even better than the extracts, it could provide farmers with a simple, low cost alternative for the control of banana and plantain nematodes.  相似文献   

大豆F_1代群体对孢囊线虫3号优势生理小种抗性遗传     

薛庆喜  马书君  张玉华 《中国油料作物学报》1991,(2)

本试验采用两个抗孢囊线虫品系84—783、CN210与当地感病的大豆品种绥农6号配制成84—783×绥农6号和绥农6号×CN210二个组合,在大豆孢囊线虫3号生理小种自然感染条件下,分析这些组合的F2代抗感病植株分离比例。结果表明,84—783、CN210的抗性基因对绥农6号的感病基因是隐性的,三对独立遗传的隐性基因控制84—783×绥农6号和绥农6号×CN210两个组合对大豆孢囊线虫3号生理小种的抗性。  相似文献   

农作物线虫病害防治措施、问题及发展方向   总被引：2，自引：0，他引：2  

陈书龙 《河北农业科学》2005,9(4):69-73

概述了农作物线虫病害的防治措施,分析了我国线虫病害防治中存在的问题,并进一步探讨了今后线虫防治研究的发展方向。  相似文献   

8种检疫线虫传入黑龙江的风险评估   总被引：1，自引：0，他引：1  

王峰  王志英  刘雪峰 《中国农学通报》2007,23(1):351-351

根据国际植物保护公约(International Plant Protection Convention,IPPC) 的国际植物检疫措施标准11(International Standard for Phytosanitary Measures 11, 2001, ISPM 11)并参考欧洲和地中海植物保护组织(European and Mediterranean Plant Protection Organization,EPPO)有害生物风险分析风险评估指导标准(EPPO Standard PM 5 /3 Guidelines on Pest Risk Analysis—Pest Risk Assessment Scheme),对马铃薯金线虫、马铃薯白线虫、相似穿孔线虫、鳞球茎茎线虫、甜菜胞囊线虫、水稻茎线虫、椰子红环腐线虫和松材线虫这8种检疫性线虫传入黑龙江省进行风险评估。风险评估表明,相似穿孔线虫传入黑龙江省具有高度风险,马铃薯金线虫、马铃薯白线虫、鳞球茎茎线虫、甜菜胞囊线虫、和松材线虫传入黑龙江省具有较高风险,水稻茎线虫风险较低、椰子红环腐线虫无风险。应该加强对风险较高的几种线虫的风险管理。  相似文献