Introduction

Introduction

INTRODUCTION liPage 1.1 Kingdom Fungi and its diversity Fungi were separated from Kingdom Plantae and are classified into a separate Kingdom Mycota (Whittaker, 1969). Whittaker classified fungi as a Kingdom on the based of fOllowing criteria, 1. These organisms are non photosynthetic and absorb nutrients produced by other organisms (saprophytes I parasites). 2. They differ from plants in their cell wall composition, thallus structure and mode of reproduction (Whittaker, 1969). The fungal cell wall is made up of chitin, cellulose or both Fungi is the most diverse Kingdoms among all (Kirk, 1995; Kirk eta!., 2001) which includes mushrooms, molds, rusts, smuts, puflballs, truffles, morels and yeasts (Alexopoulos et al., 1996). More than 70,000 species of fungi have been described; however, sorre estimates of total numbers suggest that 1.5 million species may exist (Hawksworth, 1991; Hawksworth et a!., 1995). They have successfully adapted themselves for all types of habits and habitats. Different habits and habitats have been explored which includes fungi from soil, plant parts, litter, herbivore dung, entomogenous, freshwater and marine (Barron, 1968; Ellis, 1971, 1976; Ingold, 1975; Matsushima, 1971, 1975; Subramanian, 1971, 1986; Dix and Webster, 1995; Kohlmeyer and Kohlmeyer, 1979). Some fungi are microscopic and other extends for more than a thousand acres like mycorrhizal fungi Fungi have generally been identified and classified based on morphology of spores and spore producing structures. Criteria such as cultural characters and developrrental biology have been added as useful tools in subsequent years. Reliable diagnostic tools and excellent taxonomic keys are available fur identification of fungi (Kirk et al., 2001). Over the years, several studies have been done to document the diversity of fungi from various furest types (Dix and Webster, 1995). A landmark paper provided several qualified estimates of the number of fungi on the Earth based on ratios of known fungi to plant species in regions where fungi were considered to be well studied (Hawksworth, 1991). "Estimate G" of 1.5 million species was accepted as a reasonable working hypothesis based on a fungus to plant ratio of 6:1, in contrast to the much lower 50 to 60 years old estimates by Bisby and Ainsworth (1943) of 1,00,000 fungal species and by Martin (1951) of 2,50,000 species based on one 21Page fungus for every Phanerogam known at the time. A more recent estimate of the total number of fungi is also low (7,20,256) compared to present estimates that include enviromrental samples (Schmit and Mueller, 2007). The Dictionary ofFungi (Kirk et al., 2008) reported 97,330 species of fungi with descriptions. The addition of 1300 microsporidians brings the total of all described fungi to about 99,000 species. The Dictionary's estimate ofknown species has almost tripled in the period between the first edition in 1943 (38,000 described species) and now, amounting to an increase of more than 60,000 described species over the 65 years period (Jarres et al., 2006; White et al., 2006; Hibbett et al., 2007; Kirk eta!., 2008; Lee et al., 2010). Since the discovery ofPenicillin from the fungus Penicillium (Fleming, 1929), there has been much focus on the production of antibacterial agents from the filamentous fungi (Al-Hilli and Smith, 1992; Fischer et al., 2000; Florianowicz, 1998; Larena and Melgarejo, 1996; Mayordomo et al., 2000; Rodrigues et a/., 2000). Although there is early reference to the antibacterial activities exhibited by fungi that belong to the subdivision, Basidiomycota (Brian, 1951; Robbins et al., 1947; Takeuchi, 1969), it is only within the last ten years that a broader range of genera, species and isolates from this division has been explored in more detail for antibiotic properties (Anke et al., 1980; Coletto and Mondino, 1991; Lorenzen and Anke, 1998; Rosecke and Konig, 2000; Wasser and Weis, 1999a, b, c and Wasser, 2002). Medicinal properties of the fungi are mainly due to presence of various secondary metabolites. These secondary rretabolites composition varies from species to species; hence correct identification is very crucial. Due to wide applications and limited morphological characters for classification it is difficult to identify fungi only on the basis of its morphology. Hence molecular markers were introduced to understand classification and evolution of this group. Recently, molecular tools such as polymerase chain reaction (PCR) have facilitated taxonomic identification and examination of phylogenetic relationships among different fungal groups. Using this as a principle process, several methods such as DNA hybridization, restriction enzyme analysis (RFLP), amplification using random primers (RAPD), amplification of microsatellite DNA, sequence analysis, electrophoretic karyotyping, etc. have been created and used in diversity as well as 3IPage evolutionary studies (Bruns et al., 1991). With high throughput geoomic sequence database on living organisms available at gene banks (NCBI), are use to understand similarities and differences at gene level between fungi and other living organisms (Hsiang and Baillie, 2004). Factors such as difficulty of isolation and failure to apply tmlecular rrethods may contribute to lower numbers of species in certain groups, but there cannot be any doubt that Ascomycetes and Basidiomycetes col11'rise the vast majority of fungal diversity (James et al., 2006; White et al., 2006; Hibbett et al., 2007; Kirk et al., 2008 and Lee et al., 2010). Hawksworth's (1991) estimate of 1.5 million species is considered to be conservative, because of numerous potential fungal habitats and localities remain understudied (Hawksworth and Rossman, 1997; Hawksworth, 2001). Furthertmre, the use of molecular methods had not yet been considered as a means of species discovery. For example, analysis of environmental DNA samples from a soil community revealed a high rate of new species accumulation at the site, and these data supported an estimate of 3.5 to 5.1 million species (O'Brien et al., 2005 and Blackwell, 2011). The Kingdom Fungi incorporates an enortmus diversity of taxa with varied ecology, life cycle strategies and tmrphologies. The Kingdom Fungi (Eumycota) was further classified into four Divisions/Phylum, which includes Chytridiomycota, Zygomycota, Ascomycota and Basidiomycota (Webster and Weber, 2007). The rDNA study revealed that Divisions Chytridiomycota and Zygomycota are primitive and Divisions Ascomycota and Basidiomycota are evolved amongst all (Wilmotte et al., 1993; Hibbett and Thorn, 2001; Swann and Taylor, 1995; Wells and Bandoni, 2001; Hibbett, 2006 and Hibbett, 2007). 1.2 Division: Basidiomycota The division Basidiomycota is a large and diverse group encompasses mushrooms, boletes, puffballs, earthstars, stinkhorns, bird's nest fungi, jelly fungi, bracket or shelf fungi, rust and smut fungi (Alexopoulos et al., 1996). The rrembers of Basidiomycota reproduced sexually as well as asexually. The tmst prominent and familiar Basidiomycota developed mushrooms fruiting body as a sexual reproductive structures (Fell et al., 2001). It encloses about 30,000 described species and covers a 41Page total of37% of the described species oftrue Fungi (Kirk eta/., 2001). Basidiomycota are found in virtually all terrestrial ecosystems, as well as freshwater and marine habitats (Kohlmeyer and Kohlmeyer, 1979; Hibbett and Binder, 2001 ). The main characteristic feature of Basidiomycota is that, they all produce basidiospores (sexual spore) exogenously on a reproductive organ called a basidium from which this division takes its natre. The each cell in the thallus contains two haploid nuclei resulting from a mating event, is another characteristic feature. C.lamp connections are a kind of hypha! outgrowth that is unique to Basidiomycota, with sotre exceptions. Even though Basidiomycota consist of all kinds of morphologically variable fruit bodies, they proved to be a rrx:mophyletic lineage arrx>ng fungi in the phylogenetic analysis of rDN A fungal sequences (Wilmotte et al., 1993; Hibbett and Thorn, 2001; Swann and Taylor, 1995; Wells and Bandon~ 2001; Hibbett, 2006 and Hibbett, 2007). Ascomycota and Basidiomycota were found to be rrx>nophyletic groups derived from Chytridiomycota and Zygomycota (Bruns et al., 1992; Wilmotte et al., 1993). Molecular evolution studies revealed that Basidiomycota and Ascomycota, non-flagellated fungal Division, are the mostly closely related (Bowman et al., 1992). According to McLaughlin et al., (2001) recent classification Phylum Basidiomycota divided in to 4 classes viz. Homobasidiomycetes (fungi with holobasidia, e.g. Agarics and Polypores), Heterobasidiomycetes (fungi with heterobasidia, e.g. Jelly fungi), Urediniomycetes (e.g. Rust fungi) and Ustilaginomycetes (e.g. Smut fungi). Further class Homobasidiomycetes divided in to 8 clades. The Polyporide clade consists of :family Ganodermataceae (McLaughlin et al., 2001) and members of :family Ganodermataceae have been considered for the present investigation. 1.3 Family: Ganodermataceae The members of :family Ganodermataceae Donk. are characterized by unique double-walled basidiospores. The shape and size of basidiospores and the texture of pileus surfaces are important characteristics that distinguish this family menber. Overall the members belong to this :family displays following characters: 51 Page Basidiocarps may be perennial or annual, which may be stipitate or pileate. If stipe present, round or flattened, dull to shiny and usually have a

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