Current World Environment

Introduction

The quality and quantity of organic materials present in the soil have a direct effect on the fungal population of the soil. The development of microfungi is especially favoured by soils having an acidic reaction and where the aerobic condition is likely to be present near the surface.

Fungi play a focal role in nutrient cycling by regulating soil biological activity. However the role at which organic matter is decomposed by the microbes is interrelated to the chemical composition of the substrate as well as environmental conditions (Arunachalam et al., 1997). Fungi come in many different species, sizes, and shapes in soil. The numbers and kinds of micro-organisms present in soil depend on many environmental factors: amount and type of nutrients available, available moisture, degree of aeration, pH, temperature etc.

GANGTOK is the capital of Sikkim. Gangtok is located in the Shivalik Hills of the eastern Himalayan range, at an altitude of 1,437 metres (4,715 ft) Gangtok features a monsoon-influenced subtropical highland climate. Because of its elevation and sheltered environment, Gangtok enjoys a mild, temperate climate all year round. The aim of the present investigation is to isolate mycoflora from Gangtok soil, and to observe the percentage contribution of different fungal species.

Material and Methods

Soil samples were collected from the different soil of Gangtok region(Rumtek Monestry, Flower Show,Tashi view point,M G road market), in a small sterilized plastic bottle. Potato Dextrose Agar (Potato 20%, Dextrose 2% and Agar 1.5%) was used to isolate fungi from soil.

Isolation of fungi – The fungal species were isolated by serial dilution method, 1g of soil sample was suspended in 10ml double distilled water to make microbial suspension, this suspension was used to make microbial concentration (10^-1 - 10^-5). 1ml of microbial suspension of each concentration were added to sterile petri dishes (triplicate of each dilution) containing 15ml of sterile potato dextrose agar media. The Petri dishes were then incubated for 4-6 days for 26±10C. After incubation the fungi were identified and frequency distribution of fungal species was investigated. 
 

Table 1: Observations of different fungal species from Gangtok soil Click here to view table

Results and Discussions

During the investigation period 146 fungal colonies of 22 fungal species were observed. The maximum fungal species belongs to the Ascomycotina class - 12 fungal species and 92 colonies. 7 fungal species and 29 colonies found belong to the Deuteromycotina. In Zygomycotina class 2 fungal species and 18 colonies were observed. 7 colonies of mycelia sterilia (white) was observed among total 146 colonies (Table 1). The results of present investigation revel the various work done by researchers. Some Aspergillus species such as Aspergillus niger and A. temari were isolated from soil of forest and cave ecosystems of Taiwan by Hsu and Agoramoorthy (2001). Sharma (2009) studied soil mycoflora of Yumthang valley & observed that maximum contribution was of class Ascomycotina .Microbial analysis of different soil samples of selected site in Obafemi Awolowo University, Nigeria was investigated by Ogunmwonyi et al. (2008) they found Aspergillus niger as a dominated fungi among all, in the present investigation A. fumigatus found dominated in different fungal species. Baxter and Illston (1980) found some fungal species such as Alternaria  alternate, Chrysosporlum pannorum, Cladosporium cladosporioides, Fusarium sp., Mucor hiemalis, M. racemosus etc. from low temperature region of New  Zealand, in the present work we have also found similar  fungal  genera  such  as  Alternaria, Cladosporium, Mucor etc. from the low temperature region of Gangtok. Fungi belonging to genera Acremonium, Aspergillus, Cladosporium, Fusarium and Trichoderma were isolates from Antarctic soils by Singh et al. (2006). Species of Penicillium and Trichoderma were found from different tea growing locations in India by Pandey et al. (2001) The fungi were isolated from mesophillic temperature ranges of 15°C to 35°C. About 90 fungal stains were isolates form the soil of Kotri barrage, Pakistan by Suhail et al. (2007). Among the 21 Aspergillus species isolated, the A. niger was found as dominant.

Conclusion

The fungi obtained from the site of present investigation belong to low temperature region. Now it was concluded that the isolated fungal species were get adopted at the low temperature. 

References 
 

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