Exploitation of the nematophagous fungal Verticillium chlamydosporium Goddard for the biological control of root-knot nematodes (Meloidogyne spp.).

Author(s):  
B. R. Kerry
1995 ◽  
Vol 73 (S1) ◽  
pp. 65-70 ◽  
Author(s):  
B. R. Kerry

The nematophagous fungus, Verticillium chlamydosporium, has considerable potential as a biological control agent for root-knot nematodes on a range of crops. The fungus is a general facultative parasite that attacks the eggs of several nematode species. The biology of the fungus is reviewed and the need for a detailed understanding of its ecology for its rational use as a biological control agent is highlighted. Isolates of the fungus must colonize the rhizosphere to be effective control agents. Plants differ in their ability to support the fungus and greatest control is achieved on those cultivars that support abundant growth of the fungus but produce only limited galling in response to nematode attack. On such plants, most eggs produced by nematodes are exposed to parasitism by this nematophagous fungus in the rhizosphere. Key words: biological control, nematophagous fungi, root-knot nematodes, Verticillium chlamydosporium.


Nematology ◽  
2017 ◽  
Vol 19 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Israel L. Medina ◽  
Cesar B. Gomes ◽  
Valdir R. Correa ◽  
Vanessa S. Mattos ◽  
Philippe Castagnone-Sereno ◽  
...  

Root-knot nematodes (Meloidogyne spp.) significantly impact potato production worldwide and in Brazil they are considered one of the most important group of nematodes affecting potatoes. The objectives of this study were to survey Meloidogyne spp. associated with potatoes in Brazil, determine their genetic diversity and assess the aggressiveness of M. javanica on two susceptible potato cultivars. Fifty-seven root-knot nematode populations were identified using esterase phenotyping, including Meloidogyne javanica, M. incognita, M. arenaria and M. ethiopica. Overall, root-knot nematodes were present in ca 43% of sampled sites, in which M. javanica was the most prevalent species, and the phenotypes Est J3, J2a and J2 occurred in 91.2, 6.7 and 2.1% of the positive samples, respectively. Other species, such as M. incognita, M. arenaria and M. ethiopica, were found less frequently and occurred at rates of 6.4, 4.3 and 2.1% of the samples, respectively. Sometimes, M. javanica was found in mixtures with other root-knot nematodes in ca 10.6% of sites containing Meloidogyne. After confirming the identification of 17 isolates of M. javanica and one isolate each of M. incognita, M. arenaria and M. ethiopica by SCAR markers, the populations were used to infer their genetic diversity using RAPD markers. Results revealed low intraspecifc genetic diversity among isolates (13.9%) for M. javanica. Similarly, M. javanica sub-populations (J2a) clustered together (81% of bootstrap), indicating subtle variation from typical J3 populations. The aggressiveness of four populations of M. javanica from different Brazilian states on two susceptible potato cultivars was tested under glasshouse conditions. Results indicated differences in aggressiveness among these populations and showed that potato disease was proportional to nematode reproduction factor.


Nematology ◽  
2000 ◽  
Vol 2 (8) ◽  
pp. 907-916 ◽  
Author(s):  
Ngo Thi Xuyen ◽  
Raf Verlinden ◽  
Ruth Stoffelen ◽  
Dirk De Waele ◽  
Rony Swennen

AbstractTwenty-five banana varieties of section Eumusa (AA-group) and seven of the section Australimusa (Fe'i-group) from Papua New Guinea were evaluated for resistance to Radopholus similis, Pratylenchus coffeae and Meloidogyne spp. The host plant responses were compared with the susceptible reference cvs Grande Naine and Cavendish 901. In vitro propagated plants were transferred to the glasshouse in loamy sand and inoculated with approximately 1000 migratory endoparasitic nematodes at 4 weeks after planting. Reproduction of R. similis and P.coffeae in the roots was determined at 8 or 10 weeks, respectively, after inoculation. Reproduction of Meloidogyne spp. was determined 8 weeks after inoculation with 3300 to 5000 eggs. No resistance to R. similis was found in the diploid varieties. The Fe'i variety Rimina and possibly Menei were resistant to R. similis. All varieties tested were susceptible to P.coffeae and Meloidogyne spp. Tests de résistance de bananiers Eumusa et Australimusa (Musa spp.) envers les nématodes endoparasites migrateurs et galligènes - Vingt-cinq variétés de bananier de la section Eumusa (groupe AA) et sept de la section Australimusa (group Fe'i) provenant de Papouasie-Nouvelle Guinée ont été testées pour leur résistance envers Radopholus similis, Pratylenchus coffeae et Meloidogyne spp. Les résponses de ces variétés ont été comparées à celles des cultivars sensibles de référence Grande Naine et Cavendish 901. Des vitroplants ont été mis en place en serre sur un sol argilo-sableux et inoculés 4 semaines après plantation avec environ 1000 R. similis ou P.coffeae dont la reproduction a été déterminée 8 et 10 semaines, respectivement, après inoculation. La reproduction de Meloidogyne spp. l'a été 8 semaines après inoculation avec 3300 à 5000 oeufs. Aucune résistance à R. similis n'a été observée chez les variétés diploïdes. Les variétés du groupe Fe'i Rimina et Menei se sont montrées résistantes à R. similis, avec un certain doute dans le cas de la dernière. Toutes les variétés testées sont sensibles à P.coffeae et Meloidogyne spp.


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