Meloidogyne pisi n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitising pea in Brazil

Abstract

AbstractMeloidogyne pisi n. sp. is described and illustrated from specimens obtained from roots of pea cv. Mikado in Brasilia, Brazil. The female perineal pattern is variable in shape, most are rounded to ovoid, whereas others have a moderately high, squarish dorsal arch, and can be marked with several striae parallel to the vulva or may be nearly free of striae. Lateral fields may contain a few irregular, wavy, transverse striae or be difficult to discern. Female medial lips are wide and long, sometimes with distinctly indented outer margins; the lateral lips are large and triangular, head annule is wide and marked by incomplete annulations and transverse folds. Stylet is 13-17 μm long with large, elongated knobs and a shaft that is cylindrical, straight and thick. Lumen lining of pharynx containing numerous rounded cuticular thickenings throughout its length; excretory pore located between base of stylet and median bulb. Males are 893-2510 μm long with a 19-26 μm long stylet bearing large elongated knobs, shaft marked with small, rounded projections. Second-stage juveniles are 374-463 μm long with medial lips often indented medially and 10-11 μm long stylet. Tail slender, 42-66 μm long with large irregular annules in posterior region, a slightly pointed tip and hyaline region 9-17 μm long. Many galls and egg masses are produced on tomato, tobacco and varieties of pea and bean. Few galls occur on watermelon and corn and reproduction is poor on pepper. No reproduction occurs on peanut, cotton or soybean.