Meloidogyne javanica on Peanut in Florida

Area of Science:

• Plant Nematology
• Agricultural Entomology
• Crop Protection

Background:

• Peanut (Arachis hypogaea) is a vital global crop susceptible to various plant-parasitic nematodes.
• Root-knot nematodes (Meloidogyne spp.) are major pests causing significant yield losses in agriculture.
• Previous research has documented Meloidogyne arenaria on peanuts, but M. javanica infections are less common.

Purpose of the Study:

• To identify and confirm the presence of Meloidogyne species infecting peanut in Levy County, Florida.
• To provide molecular and morphological data supporting the identification of Meloidogyne javanica.
• To document the occurrence of M. javanica on peanut in the United States.

Main Methods:

• Field collection of peanut plants and associated soil samples from Levy County, Florida.
• Morphological analysis of perineal patterns of adult female nematodes.
• Biochemical characterization using esterase and malate dehydrogenase isozyme electrophoresis on polyacrylamide gels.

Main Results:

• A mixed population of Meloidogyne arenaria race 1 and Meloidogyne javanica race 3 was identified.
• Isozyme analysis revealed the characteristic J3 esterase phenotype for M. javanica in up to 29% of analyzed females.
• Perineal pattern analysis corroborated the identification of M. javanica.

Conclusions:

• Meloidogyne javanica race 3 is confirmed to infect peanut in Florida, indicating a potential expansion of its host range or geographic distribution.
• This represents the third documented instance of M. javanica infecting peanut in the United States.
• Integrated pest management strategies for peanut cultivation in Florida should consider the presence of both M. arenaria and M. javanica.