Post-infection Development and Morphology of Meloidogyne cruciani

Abstract

The development and life stages of Meloidogyne cruciani on tomato was studied at 28 C. Roots of 2-wk-old 'Rutgers' tomato seedlings were exposed to inoculum for 24 h, rinsed, and the seedlings repotted. No major changes in juvenile development were observed prior to 8 days after inoculation. At 11 days the second-stage juvenile had enlarged considerably. The genital primordium had not yet asumed the V-shape characteristic of developing females, but the presence of rectal glands identified the juveniles as females. At this time (11 days), two additional, previously undescribed esophageal lobes were first observed; they were adjacent to the dorsal and subventral glands. After molting from second to third stage, the stylet cone, shaft, and the lumen of the stylet knobs are shed and remain attached to the second-stage cuticle. The excretory duct of the third-stage juveniles was directed anteriorly from the excretory pore of the second-stage cuticle and appear attached to the body wall of the third-stage juveniles opposite the procorpus. At 19 days after inoculation, the last molt took place. The adult female possessed a new stylet, a large five-gland esophagus, a prominent excretory system ending in a unicellular gland and a fully developed reproductive system. Key words: life cycle, root-knot nematode, esophageal glands, excretory system, rectal glands.