Effect of some plant growth-promoting rhizobacteria strains on root-knot nematode, Meloidogyne incognita, on tomatoes

Abstract

Root-knot nematode, Meloidogyne incognita, is one of the main problems in vegetable-growing regions, decreasing yield quality and quantity worldwide. Root-knot nematode management tactics mostly involve chemical control which is a threat to the environment, consequences to human health. Biological control of nematodes is considered to be one of the best alternatives to the chemical control. In this study, the effect of some bacterial isolates against M. incognita was determined on tomato in the greenhouse. The trial was designed as a randomized complete block, consisting of 15 plant growth-promoting rhizobacteria (PGPR) strains and 2 control groups (−, +) with 10 replications, total of 170 pots. Two days after transplanting the bacteria-treated tomato (Solanum lycopersicum cv. 56-56 F1) seedlings in the sterile soil in pots, the plants were inoculated with 1000 eggs or J2s of M. incognita/pot. At the end of a 90-day plant-growing period, isolate ZHA90 of Bacillus pumilus decreased plant root galling which, in turn, increased plant height, shoot fresh and dry weight, and root fresh weight. Isolates ZHA296 and ZHA178 of Paenibacillus castaneae reduced the number of egg masses and root galling with no effects on plant growth compared to the control (+). While the isolate ZHA17 of Mycobacterium immunogenum increased plant height and shoot fresh weight, ZHA57 of the same bacterium enhanced significantly only plant height. Results indicated that among 15 bacterial strains studied, ZHA296 and ZHA178 of P. castaneae and ZHA17 and ZHA57 of M. immunogenum were identified as the promising biocontrol agents for the future nematode management tactics.

Impact of Plant Growth Promoting Rhizobacteria in the Orchestration of Lycopersicon esculentum Mill. Resistance to Plant Parasitic Nematodes: A Metabolomic Approach to Evaluate Defense Responses Under Field Conditions

“…), phosphate solubilization, siderophore production, nitrogen fixation and protection towards different pathogenic organisms including PPNs [20,21]. The PGPR mediated plant resistance towards PPNs is provided by production of various antagonistic compounds, lytic enzymes, toxins and antibiotics that inhibit the nematode proliferation or directly killing them [22]. Moreover, PGPR also colonises the plant roots in the rhizosphere, produces various metabolites and their by-products that either affect the motility of PPN, or their emergence and penetration within the plant roots [23].…”

Evaluation of four rhizobacteria on tomato growth and suppression of root-knot nematode, Meloidogyne javanica under greenhouse conditions, a pilot study

“…Similarly P. polymyxa strain GBR-1 reduced egg hatching and population of M. incognita (Khan et al 2008). Based on a study performed by Cetintas et al (2018) among 15 bacterial strains studied, 2 strains of Paenibacillus castaneae and 2 strains of Mycobacterium immunogenum were identified as the best promising biocontrol agents for the management of M. incognita. Prevention of egg hatching is one of the mechanisms to emerge resistance against RKNs by plant growth-promoting bacteria.…”

In vitro evaluation of some isolated bacteria against the plant parasite nematode Meloidogyne incognita

“…Batool et al (2013) have reported that the strain P. aeruginosa caused more than 90% mortality in in vitro tests, performed with M. javanica, due to the high secretion of chitinase. Cetintas et al (2018) reported that, among 15 studied bacterial strains, the strains Paenibacillus castaneae and Mycobacterium immunogenum are found to be best biocontrol agents for management of the nematode Meloidogyne incognita.…”