Download TAXONOMY AND ECOLOGY OF MACROFUNGAL DIVERSITY IN

TAXONOMY AND ECOLOGY OF MACROFUNGAL DIVERSITY IN PULNEY
HILLS, WESTERN GHATS
Introduction
Microorganisms are the first to appear on earth and are the essential part of the
environment, contributing to the maintenance of stable ecosystem and have spread universally in
close association with living and non living objects. This has resulted in the formation of a
complex interrelationship among man, plants, microorganisms and the environment. Among all
organisms, fungi are the second largest group in the world after insects (Hawksworth, 1991,
2001). They are cosmopolitan in distribution, found in air, water, soil, on dead organic matters,
living things, etc. They are the major components of tropical ecosystems throughout the world,
involved in innumerable interaction with plants, animals and man, ranging from saprophytism to
parasitism and symbiosis. Knowledge about the taxonomy and biology of tropical fungi has
immediate relevance to the control of harmful interactions and the harnessing of useful fungal
activities for human welfare (Subramanian, 1982).
Fungi are extremely valuable sources of chemicals, including various antibiotics and also
have great potential as biological control for many serious pests. As noted by Hawskworth
(1991), “The world’s undescribed fungi can be viewed as a massive potential resource which
awaits realization”. Their existence has been recognized almost since the beginning of man’s
recorded experiences and impression of nature (Ainsworth, 1976). They are found wherever they
are searched for and their spores are found anywhere that spore traps are exposed (Davies et al.,
1974; Kramer & Pady, 1966) or soil samples are plated (Cooke, 1958).
Fungi represent a major clade in the tree of life (Maddison & Schulz, 2006) and their
traditional circumscription included all eukaryotic, heterotrophic, absorptive organism that
develop diffused, branched, tubular bodies and reproduce by means of spore (Kendrick, 2000).
Fungi are heterotrophic, eukaryotic organisms without the capacity to produce their own food
supplies and are thus completely dependent on preformed organic matters. They have neither
photosynthetic nor chemosynthetic pigments nor capabilities for these processes. Depending
upon the source of absorption and association with its partner or associated substratum, fungi are
classified as saprophytes, parasites and symbionts. The parasites which are totally dependent on
living organisms are called obligate parasites. The obligate parasites have to adjust and modify
themselves with their partners for their survival. Certain parasites absorb nutrient from the living
tissues, without killing them by the specialized organs like appressoria, haustoria or nutritive
hyphae. These are called biotrophs.
Fungi are important components of biodiversity in tropical forest. As a major contributor
to the maintenance of the earth’s ecosystem, biosphere and biogeochemical cycles, fungi perform
unique and indispensable activities on which organisms including human depend (Hawksworth
& Colwell, 1992). From the late 1940s, there has been a growing interest in mycology and fungal
diseases of plants and it has motivated the studies on fungi and their ecology (Subramanian,
1982, 1986). Though, numerous species of fungi have been reported from the Western Ghats
(Rangaswami et al., 1970; Bilgrami et al., 1991), there appears to have been no study related to
the diversity or dynamics of fungal population in forest (Subramanian, 1986). General ideas
about species diversity suggest that habitat heterogeneity is a major factor controlling diversity
(Gentry, 1988).
The tropics are generally considered to house the greatest biodiversity on earth. Large
number of new fungal species is collected from the tropics from time to time by mycologists. An
analysis of the newly described fungi from different parts of the world during 1981-90 indicated
that around 50% were only discovered in the tropics (Hawksworth, 1993). The fungal diversity is
apparently the richest in the tropical areas of the globe. The number of species of fungi described
from India is around 6900 (Bilgrami et al., 1991).There have been several estimates of global
fungal numbers ranging from less than one million to more than nine million (Cannon, 1997;
Hyde et al., 2007), although 1.5 million is generally considered to be a reasonably accurate
working figure (Hyde et al., 2007). It was estimated that, there were approximately 69,000 taxa
known in 1990 and there was an estimated annual rate of 1700 new species being described
(Hawksworth, 1991). Revised estimates of known species are 75,000 (Hawksworth, 2001) or
90,000 (Kirk et al., 2001).
The first part of this review is a brief historic introduction of the taxonomic position of
macro-fungi. The second part presents the ecological role of macro-fungi from the viewpoint of
mycorrhiza. From the 18th century to early 20th century, organisms were recognized in a
simplified two-kingdom system; Animalia and Plantae. In this system fungi are classified into
the Plantae. In 1969, the five kingdom-system comprised of plantae, animalia and fungi was
proposed and each of them was developed based on unique evolutionary schemes. Today, the
results of molecular systematics show polyphyletism among the fungi in the five-kingdom
system; there are "true-fungi" and "pseudo-fungi". True-fungi can be classified into 4 groups;
Basidiomycota, Ascomycota, Zygomycota and Chytridiomycota. "Macro-fungi" belong to the
true-fungi; some belong to the Basidiomycota and others to the Ascomycota. The ecological role
of macro-fungi is discussed from the viewpoint of saprophytes. The importance of macro-fungi
as a symbiont (mycorrhiza) of land plants has been gradually recognized and now we cannot
discuss the ecological system of the land without considering the mycorrhiza.
Objectives
 Survey, identification and documentation of macrofungal diversity
 To study the role macrofungi on forest ecosystem
 To Study the Ecological significance of macrofungi
 Taxonomical approach along with proper key preparation
 Promotion of awareness on economically, medicinally and nutritionally promising
mushrooms
Justification for the work
From the above background, the study on taxonomy and ecology of f macrofungal
diversity in Pulney hills was selected for the survey, identification and documentation and
enrichment the biodiversity wealth. Now a day, the classical studies especially the taxonomical
analysis of plants, animals and microbes have no scope. But abundant of natural resources in the
form of chemicals, medicines, food, drugs are hidden inside the forest resources especially on
macrofungi. Due to the unavailability of sponsorship or fund allotment for this work very few
research works have alone been done with minimal support from the funding agencies. But the
diversity of particular group of organisms should be surveyed properly for the sustainable
maintenance of biodiversity resources.
The present survey definite will helpful to document the entire macrofungal diversity of
Pulney hills with its ecology. From the present survey, a complete monograph will be developed
on macrofungi. The present study will also helpful for the researchers, drug developer and other
frontiers in the area of mycology.
Currently Department of Biology, Gandhigram Rural Institute: Deemed University
working on this theme of research. The department documenting the edible mushroom diversity
resources in the Sirumalai hills of Tamil Nadu. If I get a chance to work with the Department of
Biology, Gandhigram Rural Institute: Deemed University for both in teaching and Research
activities, the Rural student communities of the Gandhigram will be benefitted