Abstract

Perseverance of conventional herbal medicines is increasing gradually throughout the world. Considering the growing demand of ethnomedicinal plants in therapeutic treatments to our primary health care system and the role of vesicular arbuscular mycorrhizae (VAM) fungi for enhanced production of active secondary metabolites by the medicinal plants, the present work was undertaken to survey the arbuscular mycorrhizal status in some common medicinal herbs like, Abrus precatorius, Elephantopus scaber, Sida rhombifoliaand Clerodendrum indicum. As evidenced from Grid-line intersect method, all the plants under investigation were colonized by the vesicular arbuscular mycorrhizal fungi as both the vesicles and arbuscules were present in the roots. Arbuscular frequency was the highest in the roots of E. scaber (0.3 to 98.7), followed by A. precatorius (5.97 to 61.46) and lowest inC. indicum (0.1 to 31.7). Correspondingly, vesicular frequency was the highest in E. scaber(0 to 63.33) and lowest in C. indicum (31.83 to 40.2). It is apparent from the results that the extent of mycorrhizal colonization varied significantly with the seasonal variations throughout the year. Spore analysis from the rhizosphere soil sample exhibited a great deal of variation in their frequency and occurrence in different seasons of the year and also in their morphological features. The VAM/arbuscular mycorrhizae (AM) fungi observed in the present study mostly belong to the species group of Glomus.

Key words: Vesicular arbuscular mycorrhizae (VAM), arbuscular mycorrhizae (AM),Glomus species, Acaulospora scrobiculata, Sclerocystis species, Abrus precatorius,Elephantopus scaber, Sida rhombifolia, Clerodendrum indicum.