ADVERTISEMENTS:
In this article we will discuss about the work on mycorrhizal fungi in India.
Though the study of mycorrhizal fungi has been a neglected field, yet in India works on mycorrhizal fungi was started by B.K. Bakshi at Forest Research Institute, Dehra Dun. His project report Mycorrhiza and its role in forestry (1974) published by F.R.I, has served as a mile stone for the beginner.
Mishra and Sharma (1981) reported the association with Pinus kesiya of Amanita muscaria, Boletus edulis, Cenococcus geophilus, Inocybe rimosa, Russula roseipes, Scleroderma aurantium, Suillus bovinus from Meghalaya of North East Himayala.
ADVERTISEMENTS:
Moreover, association of ectomycorrhizal fungi with some other gymnosperm (Cedrus, Cryptomeria and Pinus) has been explored by R.R. Mishra and his research group. The work on this aspect done by K.S. Thind and his research group at Chandigarh cannot be overlooked. Lakhanpal (1987) has reported 72 fungal species forming mycorrhiza in several forest trees in the Western Himalaya.
At Forest Research Institute, Dehra Dun, in addition to significant research work done by B.K. Bakshi and coworkers, mycorrhizal researches are being strengthened. Amanita muscaria, L. laccata and Scleroderma citrinus were recorded from Pinus patula, and A. muscaria, and L. chinensis were identified from Eucalyptus globulus.
Ginwal (1996) surveyed oak forests of Kumaon Himalaya and reported the genera Agaricus, Amanita, Russula, Entoloma, Laccaria, Scleroderma, Rhizopogon and Tricholoma that form mycorrhiza. A total of 27 sporophore producing ectomycorrhizal fungi were identified.
Variations in genotypes of the host, biotic disturbances in the forest, tree density, soil temperature, soil pH, moisture and the presence of antagonistic microorganisms were the factors that governed the occurrence of ectomycorrhizal fungi in different oak forests.
ADVERTISEMENTS:
The western and eastern Ghats of South India have been extensively surveyed by A. Mahadevan and his research group of Madras University. Dubey (1998) have reviewed the influence of nutrients on formation and growth of ectomycorrhiza.
In India, B.K. Bakshi (1974) was the first to publish an account of 14 spore types of 5 genera of Endogonaceae (VAM Fungi) such as Glomus, Gigaspora, Acaulospora, Endogone and Sclerocystis from forest soils.
Sharma (1986, 1987) recorded the species of Acaulospora, Gigaspora, Glomus and Sclerocystis from rhizosphere soils of different forest trees of Meghalaya. Negi (1993) recorded Endogone sp. in soils of Cupressus torulosa and VA-mycorrhizal fungi in root tissues from Nainital. Vesicles of varying colours and numbers were observed on C. torulosa roots throughout the year.
The maximum infection was recorded in winter and minimum in summer seasons. In Himachal Pradesh 10 districts were periodically surveyed over a wide altitudinal range of 500 to 2500 meters. A total of ten VAM fungi of four genera were recorded.
Many epiphytic and terrestrial orchids are considerably dependent on mycorrhizal fungi for their carbon sources. Katiyar (1986) studied the mycorrhizal status in certain tropical epiphytic orchids from Khasi and Garo hills of Meghalaya. Diversity of mycorrhizal fungi in the Himalaya with emphasis on their forms, function and management has been reviewed by Dubey and Ginwal (1997).
A significant work on VAM fungi has been done by Sudhir Chandra and Kehri of the University of Allahabad especially on management of waste land and introduction in crop field for high yield of crops. D.J. Bagyaraj and his research group have done excellent work on VAM fungi as far as crop improvement is concerned. Reena and Bagyaraj (1990) screened several VAM fungi for their suitability to use as inoculants for two slow growing tree species. Acacia nilotica and Calliandra calothyrsus.
They found that the inoculated seedlings had greater plant height, leaf number, stem girth, biomass and phosphorus and zinc content. Johri and Mathew (1989) successfully produced inocula of VAM fungi in bulk on Phaseolus mungo roots of G. fasciculatus, G. caledonium, Gigaspora margarita, and G. calospora.
Of these G. margarita showed the highest percentage of root infection. Tata Energy Research Institute (TERI), New Delhi is contributing significant work on mycorrhizal fungi. In recent years researches on VAM fungi have gained momentum throughout the country.
