12838-AEJAES 6 pages Revised.e.xps

Root-knot nematode penetration and morphopathlogy of the infection sites were studied in roots, stem and hypocotyls of Luffa cylindrica, L. and effect of combined inoculation of Vesicular Arbuscular Mycorrhizae (VAM) fungi included Glomus mossae, Glomus intraradices, G. fasciculatum, Acaulospora sp. and Meloidogyne incognita (Root-knot Nematode) were investigated. The maximum number and size of galls were noticed in nematode inoculated plants. The anatomical observations of roots, stems and hypocotyl were done with the aid of a light microscope which demonstrated that Meloidogyne incognita caused rupturing of epidermis of the root of Luffa cylindrica, L. while penetrating into the inner tissues. They caused the formation of giant cells in the form of clusters. The giant cell clusters modify the internal morphology of the affected tissues. Abnormal xylem and abnormal phloem occupy a major portion near the giant cells and endodermal and pericycle cells showed hypertrophy and granular appearance of cytoplasm. Vascular discoloration (Blackness) was greater in the presence of Meloidogyne incognita compared with that by VAM alone. Histological studies showed that plants grown in VAM-infested soils contained spores in cortical region of roots and hypocotyls. In plants inoculated with both fungus and Meloidogyne incognita, the giant cells were small sized and the abnormality of vascular bundles was less. The results of this study also confirmed VAM (Arbuscular mycorrhizae fungi) as a potential bio-control agent for Meloidogyne incognita on Luffa plant.