In: Sydowia 74, (2021): 133-142; ISSN 0082-0598, DOI 10.12905/0380.sydowia74-2021-0133, Published online on August 30, 2021

Scanning electron microscopic and energy dispersive
X-ray spectroscopic studies of Drechmeria coniospora,
an endoparasitic nematophagous fungus

Geeta Saxena

ORCID 0000-0002-8434-1405, Department of Botany, Swami Shraddhanand College, University of Delhi
Alipur Delhi-110036, India

e-mail: saxenageeta96@gmail.com

Saxena G. (2021) Scanning electron microscopic and energy dispersive X-ray spectroscopic studies of Drechmeria coniospora,
an endoparasitic nematophagous fungus. – Sydowia 74: 133–142.
Nematophagous fungi are promising biological agents for the control of plant parasitic nematodes. Three general groups of
nematophagous fungi are categorized based on the mechanism by which they attack nematodes: Nematode-trapping or predatory
fungi, Egg parasitic fungi of cyst and root-knot nematodes and Endoparasitic fungi. In this study, scanning electron microscopy
and energy dispersive X- ray spectroscopy has been done on an obligate endoparasite Drechmeria coniospora. Its conidia
produce adhesive buds to attach, infect and parasitize nematodes. D. coniospora was isolated from compost soil, grown in pure
culture with Panagrellus redivivus nematode suspensions on dialysis membrane and freeze dried for these studies. Eight elements
namely Na+, Mg2+, Si, P, S, Cl-, K+ and Ca2+ were analyzed. Freeze drying was useful in preserving the original structure of
the fungus. Several conidiophores breaking out from the whole nematode body were observed. They formed conidiiferous pegs
which in turn produced cluster of conical conidia. Elemental analysis of young and mature conidiophores, conidiiferous pegs and
young and mature conidia showed high P, S and K+ contents. Although scanning electron microscopic studies have been done
previously on D. coniospora, energy dispersive X- ray spectroscopy is the first attempt to study any endoparasitic fungus.

Keywords: nematophagous fungi, endoparasite, biocontrol, elemental analysis, conidiophores.