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Updated: Jun 24, 2026
Screening Cotton Genotypes for Reniform Nematode Resistance
Published on: May 2, 2019
Post-Infection Development and Histopathology of Meloidogyne incognita in Resistant Cotton
Abstract:
The numbers of Meloidogyne incognita larvae which migrated from cotton roots declined over a 16-day period, but the difference in numbers migrating from resistant and susceptible cultivars was not significant. Larvae penetrated susceptible roots, matured, and reproduced within 14 days following inoculation, whereas nematode development in the resistant roots was greatly retarded. Three types of histological responses were observed in infected, resistant roots, and these correlated with the degree of nematode development. Some galls were examined which contained only fragments of nematodes; others contained no detectable traces of developing larvae. Formation of druses in galls, but not in healthy tissue, was noted in both cultivars 20 days after inoculation. Massive invasion of roots resulted in deep longitudinal fissures of root cortex.
Insights
Meloidogyne incognita nematode development was significantly slowed in resistant cotton cultivars, showing distinct histological responses. Despite initial migration, reproduction was greatly retarded in resistant roots compared to susceptible ones.
Area of Science:
- Plant Pathology
- Nematology
- Agronomy
Background:
- Root-knot nematodes (Meloidogyne incognita) are significant pests of cotton.
- Understanding host-parasite interactions is crucial for developing resistant crop varieties.
Purpose of the Study:
- To investigate the early stages of Meloidogyne incognita infection in resistant and susceptible cotton cultivars.
- To characterize the histological responses of cotton roots to nematode invasion.
Main Methods:
- Inoculation of cotton cultivars with Meloidogyne incognita larvae.
- Monitoring nematode migration and development over a 16-day period.
- Histological examination of infected root tissues.
Main Results:
- Nematode development and reproduction were significantly retarded in resistant cotton roots compared to susceptible roots.
- Distinct histological responses, including gall formation and druses, were observed in resistant roots.
- Massive nematode invasion led to root cortex fissures in both cultivars.
Conclusions:
- Resistant cotton cultivars exhibit effective mechanisms to impede Meloidogyne incognita development.
- Histological responses in resistant roots correlate with the degree of nematode suppression.
- These findings contribute to breeding strategies for nematode-resistant cotton.
