PLANT-PARASITIC NEMATODES ASSOCIATED WITH BREADFRUIT, ARTOCARPUS ALTILIS, IN HAWAIʻI
Keywords:Helicotylenchus dihystera, Kauaʻi, Maui, Meloidogyne, Mesocriconema, Oʻahu, Paratylenchus, Pratylenchus coffeae, Rotylenchulus reniformis, Tylenchorhynchus
AbstractTwenty-five breadfruit plantings on the islands of Kauaʻi, Maui, and Oʻahu were surveyed for plant-parasitic nematodes. Soil and breadfruit root samples were collected from plantings in residences, parks, schools, botanical gardens, and breadfruit orchards. Soil samples were processed by elutriation and centrifugation for nematode extraction. Roots were subjected to mist chamber extraction for 7 days. Seven different genera of plant-parasitic nematodes (Helicotylenchus, Meloidogyne, Mesocriconema, Paratylenchus, Pratylenchus, Rotylenchulus, and Tylenchorhynchus) and one unidentified taxon in Heteroderidae were found. Helicotylenchus dihystera, Rotylenchulus reniformis, Paratylenchus sp., Pratylenchus coffeae, Meloidogyne spp., and a Heteroderid were found on all islands surveyed. Helicotylenchus dihystera was the most frequent species encountered, occurring at 68% of sites surveyed and was the most widespread plant-parasitic nematode of breadfruit on Kauaʻi. On Maui, H. dihystera, R. reniformis, and P. coffeae were found in 40% of the samples collected. Paratylenchus was the most common plant-parasitic nematode to the island of Oʻahu and was detected in 86% of the samples. Meloidogyne spp. were found in 43% of breadfruit sites on Oahʻu, and 23% and 20% of that on Kauaʻi and Maui, respectively, but in low abundance on all islands. Soil samples yielded Mesocriconema at sites on Kauaʻi and Oʻahu, and Tylenchorhynchus on Oʻahu. Plant-parasitic nematodes were absent from 12% of the locations surveyed. An unidentified nematode in the Heteroderidae was detected in samples from each island, all from botanical gardens.