First report of Quinisulcius capitatus (Allen, 1955) Siddiqi, 1971 (Telotylenchidae) in Costa Rica: morphological and molecular characterization

Abstract

During a survey of plant-parasitic nematodes in Costa Rica, Quinisulcius capitatus was isolated and identified for the first time in three locations: Barva and Santa Bárbara in the Heredia province, and Vázquez de Coronado in the San José province. The nematodes were extracted from soil samples by the sugar solution centrifugation-flotation method, and the specimens described and characterized based on integrative taxonomy. The adult nematodes of Q. capitatus are in accordance with the type population, but displayed slight morphometric variations in relation to those originally described: body length of 649.5-875.7 vs. 630-850, style length of 13.7-17 vs. 16-18 and percentage of vulva of 52.7-59.9 vs. 51-58. The D2-D3 expansion segments of the 28S rDNA from the recovered populations were sequenced and used in the phylogenetic analysis. The Costa Rican populations showed a high similarity and formed a separate clade with the Pakistani and Ethiopian populations deposited in the GenBank® database. This study expands the species geographic distribution and provides the first morphometric and molecular characterization of Q. capitatus from Costa Rica.

KEYWORDS: Plant-parasitic nematode, stunt nematode, integrative taxonomy.