Esterase Polymorphism in Meloidogyne konaensis

Area of Science:

• Plant Nematology
• Molecular Entomology
• Biochemical Genetics

Background:

• Meloidogyne konaensis is a significant pest of coffee.
• Previous observations suggested potential esterase polymorphism in M. konaensis populations.

Purpose of the Study:

• To investigate the esterase polymorphism in Meloidogyne konaensis.
• To determine the effect of esterase phenotype on parasitic ability and host range.

Main Methods:

• Esterase phenotypes were analyzed in field-collected and greenhouse-cultured M. konaensis.
• Nematode reproduction and parasitism were assessed on various plant hosts (tomato, cucumber, coffee) under controlled conditions.
• Morphological characterization of different esterase phenotype isolates was performed.

Main Results:

• At least four distinct esterase phenotypes were identified in M. konaensis populations, with F1 and I1 being most common.
• Esterase phenotype was stable across different temperatures (22-33°C) on tomato.
• Single-egg-mass lines showed segregation of esterase phenotypes, indicating genetic basis.
• Isolates with different esterase phenotypes (F1, I1, F1-I1) exhibited varying parasitic abilities and host ranges.
• Only the F1 isolate parasitized Coffea arabica, while the F1-I1 isolate showed higher reproduction on tomato and cucumber.

Conclusions:

• Meloidogyne konaensis displays significant esterase polymorphism, influencing its parasitic capabilities.
• The F1 esterase phenotype is a potential marker for identifying isolates that parasitize coffee.
• Understanding this polymorphism is crucial for managing M. konaensis in coffee production.