scholarly journals Histopathology of Interrelations between Fusarium oxysporum f. sp. dioscoreae and two nematode species on yam

1969 ◽  
Vol 70 (4) ◽  
pp. 245-254
Author(s):  
Ana E. Montalvo ◽  
Pedro L. Meléndez
Keyword(s):  
Fusarium Oxysporum ◽  
Meloidogyne Incognita ◽  
Vascular System ◽  
Nematode Species ◽  
Root Knot Nematode ◽  
Dioscorea Rotundata ◽  
Pratylenchus Coffeae ◽  
Lesion Nematode ◽  
Root Tissues ◽  
Histopathological Effects

Experiments were conducted in the greenhouse to elucidate the histopathological effects of a possible interrelationship between the nematodes Meloidogyne incognita and Pratylenchus coffeae and the fungus Fusarium oxysporum f. sp. dioscoreae on yam (Dioscorea rotundata cv Habanero). Separate and combined inoculations were made with the fungus and the nematodes. Longitudinal and transverse sections of root tissues collected at 14, 42 and 72 days after inoculation showed that colonization by the fungus occurred indiscriminately, either inter- or intracellularly. Colonization in the stem was restricted to the vascular system, where abundant proliferation of hyphae was observed, mainly in the nodal tissues. Apparently, the root-knot nematode (M. incognita), as well as the fungus, colonized different sectors of the tissues invaded. However, abundant and vigorous hyphae were present in sections of tissues modified by M. incognita. It may be concluded from these studies that a positive Meloidogyne-Fusarium interaction occurs in yam. The lesion nematode (P. coffeae) was sometimes observed together with the fungus within the same tissues. However, this association did not appear to considerably accelerate the severity and/or the incidence of wilt caused by Fusarium.

scholarly journals Genetic Diversity, Virulence, and Meloidogyne incognita Interactions of Fusarium oxysporum Isolates Causing Cotton Wilt in Georgia

Plant Disease ◽  
2017 ◽  
Vol 101 (6) ◽  
pp. 948-956 ◽  
Author(s):  
Alois A. Bell ◽  
Robert C. Kemerait ◽  
Carlos S. Ortiz ◽  
Sandria Prom ◽  
Jose Quintana ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Fusarium Oxysporum ◽  
Meloidogyne Incognita ◽  
Root Knot Nematode ◽  
Soil Infestation ◽  
Causal Pathogen ◽  
Complementation Groups ◽  
Shoot Weight ◽  
Cotton Wilt ◽  
Significant Disease

Locally severe outbreaks of Fusarium wilt of cotton (Gossypium spp.) in South Georgia raised concerns about the genotypes of the causal pathogen, Fusarium oxysporum f. sp. vasinfectum. Vegetative complementation tests and DNA sequence analysis were used to determine genetic diversity among 492 F. oxysporum f. sp. vasinfectum isolates obtained from 107 wilted plants collected from seven fields in five counties. Eight vegetative complementation groups (VCG) were found, with VCG 01117B and VCG 01121 occurring in 66% of the infected plants. The newly recognized VCG 01121 was the major VCG in Berrien County, the center of the outbreaks. All eight VCG resulted in significant increases in the percentages of wilted leaves (27 to 53%) and significant reductions in leaf weight (40 to 67%) and shoot weight (33 to 60%) after being stem punctured into Gossypium hirsutum ‘Rowden’. They caused little or no significant reductions in shoot weight and height or increases in foliar symptoms and vascular browning in a soil-infestation assay. Soil infestation with Meloidogyne incognita race 3 (root-knot nematode) alone also failed to cause significant disease. When coinoculated with M. incognita race 3, all VCG caused moderate to severe wilt. Therefore, the VCG identified in this study belong to the vascular-competent pathotype, and should pose similar threats to cotton cultivars in the presence of the root-knot nematode. Use of nematode-resistant cultivars, therefore, is probably the best approach to control the disease in Georgia.

Single pass cDNA sequencing - a powerful tool to analyse gene expression in preparasitic juveniles of the southern root-knot nematode Meloidogyne incognita

Nematology ◽  
2001 ◽  
Vol 3 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Jaap Bakker ◽  
Fred Gommers ◽  
Geert Smant ◽  
Pierre Abad ◽  
Marie-Noëlle Rosso ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cdna Library ◽  
Meloidogyne Incognita ◽  
Sequence Data ◽  
Homo Sapiens ◽  
Large Fraction ◽  
Nematode Species ◽  
Cdna Libraries ◽  
Parasitic Nematodes ◽  
Root Knot Nematode

AbstractExpressed sequence tags (EST) have been widely used to assist in gene discovery in various organisms (e.g., Arabidopsis thaliana, Caenorhabditis elegans, Mus musculus, and Homo sapiens). In this paper we describe an EST project, which aims to investigate gene expression in Meloidogyne incognita at the onset of parasitism. Approximately 1000 5′-end sequence tags were produced from a cDNA library made of freshly hatched preparasitic second stage juveniles (J2). The EST were identified in the primary transformants of the cDNA library, and assigned to nine different functional groups, including (candidate) parasitism genes. A large fraction of the EST (45%) did not have a putative homologue in public databases. Sixty five percent of the EST that could be clustered into a functional group had putative homologues in other nematode species. EST were found for virtually all parasitism related genes that have been cloned from M. incognita to date. In addition, several novel genes were tagged, including a xylanase and a chitinase gene. The efficiency of EST projects, which produce sequence data for thousands of genes in months time without any difficult pre-selections of mRNA pools, makes random sequencing cDNA libraries a superior method to identify candidates for parasitism related genes in plant-parasitic nematodes. The sequences in this paper are retrievable from Genbank with the accession numbers BE191640 to BE191741, BE217592 to BE217720, BE225324 to BE225598, BE238852 to BE239221, and BE240829 to BE240865.

scholarly journals CHARACTERIZATION OF RESISTANCE TO ROOT-KNOT NEMATODES IN SWEETPOTATO

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 868e-869
Author(s):  
J.A. Thies
Keyword(s):  
Meloidogyne Incognita ◽  
Ipomoea Batatas ◽  
Nematode Species ◽  
Plant Introduction ◽  
Root Knot Nematode ◽  
Race 1 ◽  
Race 2 ◽  
The U.S ◽  
Greenhouse Tests

Thirteen sweetpotato (Ipomoea batatas) genotypes were characterized for resistance to Meloidogyne incognita, M. javanica, M. hapla, and M. arenaria races 1 and 2 in greenhouse tests. The following sweetpotato genotypes representing a range of reactions to M. incognita were evaluated: U.S. Plant Introduction (PI) 399163 (highly resistant = HR), Sumor (HR), Nemagold (HR), Excel (HR), Tinian (HR), Hernandez (resistant = R), Jewel (R), Regal (R), Porto Rico (intermediate = I), Centennial (susceptible = S), Georgia Jet (S), Sulfur (S), and Beauregard (S). Meloidogyne incognita was most pathogenic to sweetpotato of the four Meloidogyne spp. evaluated in these studies. The U.S. Plant Introduction (PI) 399163 and Sumor were resistant to M. incognita in all tests. Only two genotypes, Beauregard and Porto Rico, were susceptible to M. javanica. All genotypes evaluated were resistant to M. hapla, M. arenaria race 1, and M. arenaria race 2. Sumor, U.S. PI 399163, and Nemagold appear to provide the highest levels of resistance against the four Meloidogyne spp. used in these studies. Since M. incognita is the most commonly occurring root-knot nematode species in sweetpotato growing areas of the southern U.S. and is pathogenic to most of the commonly grown sweetpotato cultivars, efforts to develop resistant cultivars that have desirable horticultural characteristics for the U.S. market should be directed toward this root-knot nematode species.

scholarly journals Saccharum spontaneum, a Novel Source of Resistance to Root-Lesion and Root-Knot Nematodes in Sugarcane

Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2288-2294
Author(s):  
Shamsul A. Bhuiyan ◽  
Kylie Garlick ◽  
George Piperidis
Keyword(s):  
Nematode Species ◽  
Root Lesion Nematode ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Nematode Reproduction ◽  
Final Population ◽  
Lesion Nematodes ◽  
Commercial Cultivars ◽  
Lesion Nematode ◽  
Root Lesion Nematodes

Root-lesion nematode (Pratylenchus zeae) and root-knot nematode (Meloidogyne javanica) are two important pathogens of sugarcane (Saccharum hybrid). No commercial cultivars are resistant to these nematodes in Australia. Twenty accession lines of S. spontaneum, a wild relative of sugarcane, were tested against these two nematode species. S. spontaneum lines were tested twice for resistance to root-lesion nematode and three times for root-knot nematode. Reproduction (final population/starting population) of root-lesion nematodes was significantly lower in 17 of the 20 S. spontaneum accession lines tested in two experiments compared with two commercial cultivars. Four S. spontaneum lines supported a significantly lower number of root-lesion nematodes per gram of root than that of two commercial sugarcane cultivars. Reproduction of root-knot nematodes was significantly lower in 16 S. spontaneum lines compared with two commercial cultivars. Fourteen of the S. spontaneum lines tested supported significantly fewer eggs per gram of root compared with two commercial cultivars. This study showed that S. spontaneum lines possessed resistance for root-lesion and root-knot nematodes. Targeted crossing with commercial hybrid parental lines should be conducted to introduce nematode resistance into sugarcane cultivars for the Australian sugar industry.

THE INTERACTION OF PLANT, PATHOGEN, AND SCAPTOCORIS TALPA CHAMP

1961 ◽  
Vol 39 (3) ◽  
pp. 695-703 ◽  
Author(s):  
M. I. Timonin
Keyword(s):  
Fusarium Oxysporum ◽  
Plant Pathogen ◽  
Meloidogyne Incognita ◽  
Microbial Population ◽  
Volatile Matter ◽  
Soil Samples ◽  
Root Knot Nematode ◽  
Selective Toxicity ◽  
Tomato Seedling ◽  
Tomato Seedlings

The effects of the odoriferous volatile matter produced by Scaptocoris talpa Champ on the activity of Fusarium oxysporum f. cubense (E.F.S.) Sny. and Hans., F. oxysporum f. lycopersici (Sacc.) Sny. and Hans., and Meloidogyne incognita in soil, and its phytotoxicity to tomato seedlings, were investigated.The results obtained indicated that 50–75 insects per pot protected tomato seedlings (Bonny Best) and banana plants (Gros Michel) from attack by their respective fungus pathogens and one insect per 2 grams of soil protected tomato seedlings from attack by root-knot nematode.The apparatus especially constructed to study the phytotoxicity of odoriferous volatile matter to tomato seedlings and its effect on microbial population of the soil was described. By means of this apparatus it was found that 6 days of a weak flow of a mixture of air and volatile matter produced by 350–400 insects was not phytotoxic to six tomato seedlings. Furthermore, it was also found that volatile matter produced by 800 insects, under the same conditions, was not toxic to one tomato seedling. Under similar conditions the non-phytotoxic concentration of volatile matter produced by 350–400 insects reduced the density of F. oxysporum f. cubense population in soil samples containing 25 and 15% (w/w) of moisture by 61.20 and 45.78% respectively.It was also demonstrated that one insect per 2 grams of soil infested with the root-knot nematode during 16 hours' incubation produced a nematocidal concentration of volatile matter.The possibility of selective toxicity of volatile odoriferous matter to various bacteria is also discussed.

scholarly journals Retention of Resistance to Fusarium oxysporum f. sp. niveum in Cucurbit Rootstocks Infected by Meloidogyne incognita

Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1820-1827 ◽  
Author(s):  
Anthony P. Keinath ◽  
Paula A. Agudelo
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Meloidogyne Incognita ◽  
Interspecific Hybrid ◽  
Bottle Gourd ◽  
Root Knot Nematode ◽  
Summer Squash ◽  
Race 1 ◽  
Race 2 ◽  
Southern Root Knot Nematode

Interspecific hybrid squash (Cucurbita maxima × C. moschata ‘Strong Tosa’) and bottle gourd (Lagenaria siceraria ‘Macis’) rootstocks are resistant to Fusarium oxysporum f. sp. niveum but susceptible to Meloidogyne incognita (Southern root-knot nematode). Coinfection of Early Prolific Straightneck summer squash (C. pepo) with root-knot nematode and F. oxysporum f. sp. niveum has been reported to increase susceptibility to Fusarium wilt. The objectives of this study were to determine whether such an interaction occurred between M. incognita and F. oxysporum f. sp. niveum races 1 and 2 on Strong Tosa, Macis, and watermelon cultivars Fascination (resistant to race 1) and Tri-X 313 (susceptible to both races). Hosts were inoculated in a greenhouse with one of four pathogen treatments: F. oxysporum f. sp. niveum, M. incognita, both pathogens, or neither pathogen. Galling was present on ≥10% of the root systems of 90% of the plants inoculated with M. incognita. Bottle gourd had less galling than interspecific hybrid squash. Plants not inoculated with F. oxysporum f. sp. niveum did not wilt. Four weeks after inoculation, incidence and severity of Fusarium wilt and recovery of F. oxysporum did not differ for any hosts inoculated with F. oxysporum f. sp. niveum alone and F. oxysporum f. sp. niveum plus M. incognita (host–treatment interactions not significant). In general, Early Prolific Straightneck grouped with the F. oxysporum f. sp. niveum-resistant rootstocks when inoculated with F. oxysporum f. sp. niveum race 2 and with the susceptible watermelon when inoculated with race 1, regardless of inoculation with M. incognita. Recovery of F. oxysporum from stems of inoculated watermelon was greater than recovery from the other three hosts, regardless of nematode inoculation. In conclusion, our experiments do not support the hypothesis that resistance to F. oxysporum f. sp. niveum in cucurbit rootstocks or resistant watermelon cultivars would be compromised when M. incognita infects the roots.

Genetic characterization of Meloidogyne incognita isolates from Turkey using sequence-related amplified polymorphism (SRAP)

Biologia ◽  
2012 ◽  
Vol 67 (3) ◽  
Author(s):  
Zübeyir Devran ◽  
Ömür Baysal
Keyword(s):  
Genetic Variation ◽  
Meloidogyne Incognita ◽  
Cost Effective ◽  
Nematode Species ◽  
Root Knot Nematode ◽  
Breeding Programs ◽  
Widespread Species ◽  
Resistant Varieties ◽  
Southern Root Knot Nematode

AbstractSouthern root knot nematode Meloidogyne incognita is the most widespread-species, causing serious yield losses in protected vegetables fields in the West Mediterranean region of Turkey. The knowledge of genetic variation within M. incognita is required for disease management and improvement of resistant varieties by breeding programs. In the present study, the isolates were classified into different groups based on sequence-related amplified polymorphism (SRAP) fingerprints. To our knowledge, this is the first study carried out on the characterization of M. incognita isolates using SRAP. The schematic diagram by tested primers to differentiate of M. incognita isolates was formed in discrimination of nematodes as an effective molecular tool since it is cost effective and easiness. Data presents a genetic variation on root-knot nematode species. These selected SRAP markers can be used to follow genetic structure and differentiation on M. incognita isolates in a certain region.

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