Management of Root-Knot Nematode,Meloidogyne Incognita,by integration of Paecilomyces Lilacinus with organic materials in Chilli

Studies were made to determine the efficacy of Paecilomyces lilacinus in management of root-knot nematode (Meloidogyne incognita) in soil amended with various organic matters. The soil amendments with organic additives except gram and rice husks significantly reduced the multiplication of M. incognita and the root galling caused by root-knot nematode which consequently increased the plant growth. The greatest improvement in plant growth and reduced reproduction factor and root galling was recorded in soil amendment with leaves of Calotropis procera while the least was in kail saw dust. The best protection against M. incognita was observed on the integration of organic additives with P. lilacinus, which resulted increased plant growth and reduced population build-up of nematodes and root gallings. The leaves of C. procera with P. lilacinus were most effective than all other organic materials used among the different integrated approaches. The organic amendments also increased the parasitism of P. lilacinus on M. incognita.     

Control of nematode disease of egg plant (Solanum aethiopicum) using manure

Pot experiment was conducted in the year 2010 and repeated in 2011 to examine the effects of organic manure (poultry, cow dung and domestic waste) and inorganic manure (NPK 15:15:15) on the yield, soil and root population of Meloidogyne incognita-infected Ethiopian egg plant Solanum aethiopicum in a greenhouse at Kabba college of agriculture, Ahmadu Bello University, Kabba, Nigeria. Each of the organic manure was applied as soil amendment at the rate of 5t/ha and the inorganic fertiliser (NPK) was applied at the rate of 200?kg/ha, while there was an untreated control that acted as standard check. The experimental design was a completely randomised design comprising of five treatments including control and each of the treatments was replicated four times. The result of the experiment showed that all the organic manures considered and NPK fertilisers were effective in suppressing the nematode’s negative effects on the plant, as shown by the improved yield, reduced soil and root population as well as reduced gall index of the organic and inorganic manure-treated plant compared with the control. The mean fruit yield of the manure-treated plant was of the range 18?±?1 fruits and NPK fertiliser had an average of fruit number of 17, while the untreated control recorded an average fruit number of 6.5. The organic and inorganic manure-treated plants recorded bigger fruit size compared with control, and are significantly different from the control. The soil and root population as well as root gall index are reduced in all the manure treatments compared with the control and are significantly different from the control. The result of this experiment confirmed that organic manure can be utilised to manage nematode in soil endemic with root-knot nematode M. incognita.     

Feasibility of growing Moringa oleifera as a mix-crop along with tomato for control of Meloidogyne incognita and Rotylenchulus reniformis in Egypt

Impact of nematicidal potential of drumstick, Moringa oleifera Lam. (Moringaceae), as a medicinal plant (1–4 plants per pot) is obtained when it is used as a mix-crop along with tomato cv. Super Strain B against Meloidogyne incognita and Rotylenchulus reniformis was evaluated under a greenhouse conditions (30?±?5?°C) at the National Research Centre, Egypt. The nematodes final population and their rate of build-up as well as the root gall index were significantly affected by the number of moringa plants when grown with tomato together. There was a negative correlation between the number of moringa seedlings and the final population of both nematodes. The lowest nematode final population and rate of build-up were determined at the highest number of moringa plants (four plants per pot). The highest number of root gall index (4.1) was found on roots of tomato grown alone, while, the lowest one (0.6) was found on roots of tomato grown with four plants of moringa. This type of control is considered easy, inexpensive and pollution-free.     

Evaluation of persistence and effectiveness of bacterial cell suspensions and culture filtrates against M. incognita on brinjal

Keeping in view the staid health and ecological apprehensions coupled with the use of pesticides, entomopathogenic nematodes have the potential to supersede pesticides for the management of various pests. Brinjal plants are the most seriously affected by Meloidogyne incognita. The main objective of this study was to evaluate the persistence effectiveness of bacterial cell suspensions (Xenorhabdus and Photorhabdus spp.) and their culture filtrates in soil up to 7, 14 and 21?days and their response against M. incognita as a source of biological control for nematode management. In a life cycle study, Xenorhabdus and Photorhabdus spp., isolated from Steinernema asiaticum and Heterorhabditis bacteriophora, were proved more effective in influencing the life cycle of RKNs. It was found that all the treatments of bacterial cell suspensions and their culture filtrates at all persistent times proved effective in reducing the number of females and egg masses as compared to control. It delayed penetration of nematode juveniles (J2) into host roots. It was concluded that persistence effectiveness of bacteria and their metabolites decreased in soil with time.     

Effect of abiotic resistance inducers, γ-amino-n-butyric acid (GABA), ascorbic acid and chitosan on certain enzyme activities of eggplant inoculated with root-knot nematode,Meloidogyne incognita

Treatments with γ-amino-n-butyric acid (GABA), ascorbic acid (vitamin C) and chitosan by foliar spray or root dipping technique to eggplant growing under greenhouse conditions before and after inoculation of Meloidogyne incognita showed a generalised increase in the activity of the enzymes, peroxidase (POX), polyphenol oxidase (PPO) and chitinase as compared with the infected non treated control. The maximum increase in POX activity occurred after 10?days of nematode inoculation. The relative PPO activity with chitosan at 2500?ppm, GABA at 5000?ppm and ascorbic acid at 10?ppm using root dipping was found to be 375, 338 and 175% of control, respectively. As for PPO oxidase, the maximum activity was observed after five?days of nematode inoculation by using ascorbic acid at 10?ppm followed by GABA at 5000?ppm and chitosan at 2500?ppm by root dipping (800, 767 and 600% of control), respectively, while the highest chitinase enzyme activity (281% of control) was observed using chitosan at 2500?ppm after 10?days of inoculation.     

Histological characterization of root-knot nematode resistance in cowpea and its relation to reactive oxygen species modulation

Root-knot nematodes (Meloidogyne spp.) are sedentary endoparasiteswith a broad host range which includes economically importantcrop species. Cowpea (Vigna unguiculata L. Walp) is an importantfood and fodder legume grown in many regions where root-knotnematodes are a major problem in production fields. Severalsources of resistance to root-knot nematode have been identifiedin cowpea, including the widely used Rk gene. As part of a studyto elucidate the mechanism of Rk-mediated resistance, the histologicalresponse to avirulent M. incognita feeding of a resistant cowpeacultivar CB46 was compared with a susceptible near-isogenicline (in CB46 background). Most root-knot nematode resistancemechanisms in host plants that have been examined induced ahypersensitive response (HR). However, there was no typicalHR in resistant cowpea roots and nematodes were able to developnormal feeding sites similar to those in susceptible roots upto 9–14 d post inoculation (dpi). From 14–21 dpigiant cell deterioration was observed and the female nematodesshowed arrested development and deterioration. Nematodes failedto reach maturity and did not initiate egg laying in resistantroots. These results confirmed that the induction of resistanceis relatively late in this system. Typically in pathogen resistanceHR is closely associated with an oxidative burst (OB) in infectedtissue. The level of reactive oxygen species release in bothcompatible and incompatible reactions during early and latestages of infection was also quantified. Following a basal OBduring early infection in both susceptible and resistant roots,which was also observed in mechanically wounded root tissues,no significant OB was detected up to 14 dpi, a profile consistentwith the histological observations of a delayed resistance response.These results will be useful to design gene expression experimentsto dissect Rk-mediated resistance at the molecular level. Key words: Cowpea, histology, hypersensitive response, Meloidogyne incognita, reactive oxygen species, root-knot nematode, Vigna unguiculata Received 5 November 2007; Revised 22 January 2008 Accepted 23 January 2008     

Solubilization of insoluble zinc compounds by Gluconacetobacter diazotrophicus and the detrimental action of zinc ion (Zn2+) and zinc chelates on root knot nematode Meloidogyne incognita

AIM: To examine the zinc (Zn) solubilization potential and nematicidal properties of Gluconacetobacter diazotrophicus. METHODS AND RESults: Atomic Absorption Spectrophotometer, Differential Pulse Polarography and Gas Chromatography Coupled Mass Spectrometry were used to estimate the total Zn and Zn(2+) ions and identify the organic acids present in the culture supernatants. The effect of culture filtrate of Zn-amended G. diazotrophicus PAl5 on Meloidogyne incognita in tomato was examined under gnotobiotic conditions. Gluconacetobacter diazotrophicus PAl5 effectively solubilized the Zn compounds tested and 5-ketogluconic acid was identified as the major organic acid aiding the solubilization of zinc oxide. The presence of Zn compounds in the culture filtrates of G. diazotrophicus enhanced the mortality and reduced the root penetration of M. incognita under in vitro conditions. CONCLUSIONS: 5-ketogluconic acid produced by G. diazotrophicus mediated the solubilization process and the available Zn(2+) ions enhanced the nematicidal activity of G. diazotrophicus against M. incognita. SIGNIFICANCE AND IMPACT OF THE STUDY: Zn solubilization and enhanced nematicidal activity of Zn-amended G. diazotrophicus provides the possibility of exploiting it as a plant growth promoting bacteria.     

Histologial Studies on the Root-Knot Nematodes Nonresistant and Resistant Root Apex of Humulus lupulus L.

The nematodes (Meloidogy incognita Chitwood.) invade near the root apex of the hop (Humulus lupulus L.), and usually lie near the meristematic zone. Fallowing their entrance, there are the formation of the giant cells and the consequent continuous divisions and activities of the flat meristematic cells, which result in formation of the nematode galls. Their sizes are also related to the number of nematodes. String beads nematode galls are often formed at the nematode-non resistant root part of the "Comet". The process of nematodes entering and later changing of the cells and tissue is almost the same as the formation of the nematode gall in other plants. Fewer nematodes can also enter the root tip of the highly resistant "Qingdao Dahua", but the subsequent special differentiation of the cells and tissues in the root have greatly restrained the activities of nematodes and ultimately to their death.     

不同基质中番茄菌根苗的培育及其抗南方根结线虫的效果

根结线虫病是番茄主要的土传病害,特别是保护地长期种植会加重病害的发生.接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)能提高植物抗根结线虫的能力,促进植株生长发育,减轻病害.本试验旨在评价常用基质配合施用一种生物有机肥对番茄苗生长和菌根定殖的影响,以获得菌根发育良好且生长健壮的菌根苗...