Biodiversity and Community Analysis of Plant-Parasitic and Free-Living Nematodes Associated with Maize and Other Rotational Crops from Punjab, Pakistan

Research Advances in the Plant-Nematode Interaction

Nematodes, which are highly important and abundant animals in the animal kingdom, demonstrate remarkable adaptability to various environments [...].

Efficacy of Aspergillus tubingensis GX3' Fermentation against Meloidogyne enterolobii in Tomato (Solanum lycopersicum L.)

Meloidogyne enterolobii is one of the most virulent root-knot nematodes (RKNs). Aspergillus tubingensis Raoul Mosseray, 1934, is used to produce bioactive substances, enzymes, and secondary metabolites. However, no research has been conducted yet on the efficacy of A. tubingensis against plant-parasitic nematodes. Thus, the novel research was planned to evaluate the biocontrol efficacy of A. tubingensis fermentation against M. enterolobii. The findings showed that egg hatching inhibition and mortality of M. enterolobii increased with increasing concentration of fermentation and exposure time. The maximum second-stage juveniles (J2s) mortality was achieved via 100% fermentation at 72 h. Similarly, 100% fermentation inhibited 99.9% of egg hatching at 8 d. A. tubingensis fermentation increased plant biomass, decreased second-stage juvenile invasion, and inhibited nematode development and reproduction in greenhouse conditions. A. tubingensis reduced J2 invasion into tomato roots by 42.84% with CS+ (coated seeds plants with nematodes inoculum) and 27.04% with T+ (100% fermentation broth and nematodes inoculum both) treatments. Moreover, CS+ and T+ treatments decreased nematode development by 54.31% and 21.48%, respectively. It is concluded that the A. tubingensis GX3 strain can be used as a novel microbial biocontrol agent against M. enterolobii.

Meloidogyne enterolobii risk to agriculture, its present status and future prospective for management

Meloidogyne enterolobii, commonly known as guava root-knot nematode, poses risk due to its widespread distribution and extensive host range. This species is recognized as the most virulent root-knot nematode (RKN) species because it can emerge and breed in plants that have resistance to other tropical RKNs. They cause chlorosis, stunting, and yield reductions in host plants by producing many root galls. It is extremely challenging for farmers to diagnose due to the symptoms' resemblance to nutritional inadequacies. This pathogen has recently been considered a significant worldwide threat to agricultural production. It is particularly challenging to diagnose a M. enterolobii due to the similarities between this species and other RKN species. Identified using traditional morphological and molecular techniques, which is a crucial first in integrated management. Chemical control, biological control, the adoption of resistant cultivars, and cultural control have all been developed and effectively utilized to combat root-knot nematodes in the past. The object of this study was to get about the geographical distribution, host plants, symptoms, identification, and control techniques of M. enterolobii and recommend future initiatives to progress its management.

Isolation and Characterization of Novel Biological Control Agent Clostridium beijerinckii against Meloidogyne incognita

One of the most severe soil-borne pathogens in the world is the root-knot nematode (Meloidogyne incognita). Biological control is gaining more importance as environmental awareness increases. Thus, keeping this in mind, a total of 712 bacterial strains were isolated from 117 rhizosphere soil samples and investigated for potential biological control activity against M. incognita. Strain Sneb518 (Clostridium beijerinckii) was identified as having solid biocontrol activity against M. incognita. Sneb518 demonstrated significant inhibition against M. incognita, with J2 mortality reaching 90.73% at 12 h and with eggs hatching at a rate of 6.00% at 24 h, compared to a hatchability level of 29.07% for the control. Additionally, Sneb518 was excellent for enhancing seed germination. The seeds coated with a fermentation broth containing Sneb518 efficiently boosted the germination rate to 88.49%. The effectiveness and stability of C. beijerinckii Sneb518 against M. incognita were then further evaluated in a greenhouse. According to the pot experiment data, Sneb518 considerably (p < 0.05) reduced the number of root galls and egg masses on roots and also significantly (p < 0.05) increased tomato plant growth. C. beijerinckii Sneb518-treated tomato seedlings exhibited 50.26% biocontrol effectiveness compared to the control group. Our results demonstrate that C. beijerinckii Sneb518 can be a potential biological control agent against root-knot nematode disease and a biomass enhancer. This research will give new options for the sustainable control of root-knot nematode disease in tomatoes and other host plants.