EFFECT OF DIFFERENT CARBON SOURCES ON THE GROWTH OF DIFFERENT ISOLATES OF FUSARIUM OXYSPORUM f. sp. CUBENSE IN DIFFERENT MEDIA

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2 Int. J. Agric.Sc & Vet.Med Thammaiah N et al., 2014 Research Paper ISSN Vol. 2, No. 2, May All Rights Reserved EFFECT OF DIFFERENT CARBON SOURCES ON THE GROWTH OF DIFFERENT ISOLATES OF FUSARIUM OXYSPORUM f. sp. CUBENSE IN DIFFERENT MEDIA Somu R 1, Thammaiah N 1* and G S K Swamy 2 *Corresponding Author: Thammaiah N, nthammaiah@gmail.com In vitro study was conducted to know the best carbon sources for mycelia growth of Fusarium oxysporum. f. sp. cubense. Seven carbon sources were tried by incorporating in Richard s agar and Czapek s agar media among them sucrose was found best carbon source for growth of all the three isolates of Bangalore, Channapatna and Mysore of Fusarium oxysporum f. sp. cubense Keywords: Fusarium oxysporum f. sp. cubense, Panama wilt, Carbon, s INTRODUCTION Banana is a fruit of tropics, and subtropics growing extensively in hot and humid conditions. It is grown in home garden for home consumption of the local market, but also in very big plantations for export. The world banana is general term embracing a number of species or hybrids in the genus Musa of the Musaceae. It is one of the most important fruit crops of the world as well as India. Considering the nutritive value of bananas, it is so prominent and popular among the people of India, that it is liked by both poor and rich alike. Banana is also called poor man s apple as it is the cheapest among fruits grown in the country with rich energy and nutritive values. There are several diseases recorded on banana such as, Panama wilt, Sigatoka disease, tip over disease, Bunchy top, Burrowing nematode. Among all these diseases, Panama disease also Known as Fusarium wilt or vascular wilt incited by Fusarium oxysporum f. sp. cubense (E.F. Smith) Snyd. and Hans. is one of the world s most catastrophic plant disease. At present the disease is widespread in almost all the banana growing region of India and varieties like Rasthali (AAB), Ney Poovan (AB) and Virupakshi (AAB) 1 Department of Horticultural Plant Pathology, K. R. C. College of Horticulture, Arabhavi, UHS Bagalkot, Karnataka, India. 2 Departemt of Fruit Science, K. R. C. College of Horticulture, Arabhavi, UHS Bagalkot, Karnataka, India. 1

3 are highly susceptible to this disease and threatened with extinction (Thangavelu et al., 2001). Carbon is an important element required, by all the living organisms for metabolic activities. Almost half of the dry mycelial weight of the fungal cell consists of carbon which is the main structural element (Lilly and Barnett, 1951). Hence, the present investigation was undertaken to evaluate the best carbon source for the growth of Fusarium oxysporum f. sp. cubense. MATERIALS AND METHODS An experiment was laid out during 2011 at K. R. C. College of Horticulture, Arabhavi to find out the suitable carbon sources for growth of Fusarium oxysporum f. sp. cubense. The experiment was designed in Complete Randomized Design (CRD) with three replications and seven treatments. This experiment was conducted to find out the source of carbon, which is used most efficiently by the fungus for its growth. Several carbon sources were tried by incorporating them in Richard s and Czapek s broth for different isolates viz., Bangalore, Channapatna and Mysore. The quantity of each carbon compound to be added was determined on the basis of their molecular weight, so as to provide equivalent amount of carbon as was of sucrose present in the basal medium. The carbon compounds used were dextrose, fructose, mannitol, starch, maltose, sucrose and lactose. 30 ml of each media were poured into 100 ml flasks plugged with non absorbent cotton and autoclaved at 1.1 kg/cm 2 pressure for 15 min. Each of the treatment was replicated thrice. All the flasks were aseptically inoculated with 5 mm of prepared suspension of 10 days old culture of Fusarium oxysporum. f. sp. cubense. Inoculated flasks were incubated at 26 ± 1 C for nine days. The mycelia were harvested and dried to a constant weight. Results were analyzed statistically. RESULTS AND DISCUSSION The effect of seven carbon sources on growth of three different isolates of Fusarium oxysporum f. sp. cubense were studied in Richard s broth and Czapek s broth. The mean dry weight of Table 1: Effect of Different Carbon Sources on Growth of Different s of Fusarium oxysporum f. sp. cubense on Richard s Media Carbon Source Mean Dry Weight of Mycelium (mg) Bangalore Channapatna Mysore Dextrose Fructose Mannitol Starch Maltose Sucrose Lactose S.Em± % Table 2: Effect of Different Carbon Sources on Growth of Different s of Fusarium oxysporum f. sp. cubense on Czapek s Media Carbon Source Mean Dry Weight of Mycelium (mg) Bangalore Channapatna Mysore Dextrose Fructose Mannitol Starch Maltose Sucrose Lactose S.Em± %

4 Plate 1: Dry Weight of Different s of Fusarium oxysporum f. sp. cubense on Different Carbon Sources in Richard s Medium 3

5 Plate 2: Dry Weight of Different s of Fusarium oxysporum f. sp. cubense on Different Carbon Sources in Czapek s Medium 4

6 mycelium was recorded after nine days of incubation. The result are furnished in Tables 1 and 2, Plates 1 and 2. Growth of Different s in Richard s Broth The results showed that the isolates of Fusarium oxysporum f. sp. cubense could utilize carbon sources with considerable variation in their growth efficiency on Richards media. The Bangalore isolate utilized sucrose better than other carbon sources with growth of mg followed by maltose ( mg), mannitol ( mg), fructose ( mg), dextrose ( mg) and lactose ( mg). Least growth was observed in starch ( mg). Sucrose was the best carbon source utilized by Channapatna isolate and showed maximum growth of mg followed by fructose ( mg), starch ( mg), maltose ( mg), mannitol ( mg) and lactose ( mg). Least growth was seen in dextrose ( mg). Mysore isolate produced maximum growth of mg in sucrose and found to be a best carbon source followed by fructose ( mg), maltose ( mg), starch ( mg), mannitol ( mg) and dextrose ( mg). Least growth was seen in lactose ( mg). Growth of Different s in Czapek s Broth In Czapek s media the Bangalore isolate produced maximum mycelial growth of mg in sucrose followed by mannitol ( mg), dextrose ( mg), starch ( mg), maltose ( mg) and fructose ( mg). Least mycelial growth was noticed in lactose ( mg). Channapatna isolate produced highest growth of mg in sucrose followed by mannitol ( mg), dextrose ( mg), maltose ( mg), starch ( mg) and fructose ( mg). Least growth was observed in lactose ( mg). Mysore isolate also showed the maximum growth by utilizing sucrose as its carbon source with a mean mycelial growth of mg followed by maltose ( mg), fructose ( mg), starch ( mg), mannitol ( mg) and dextrose ( mg). Least growth was observed in lactose ( mg). In the present study, among the carbon sources tested, sucrose supported maximum growth for Bangalore, Channapatna and Mysore isolates of Fusarium oxysporum f. sp. cubense in Richard s as well as in Czapek s medium. Minimum growth was observed in starch, dextrose and lactose of Bangalore, Channapatna, and Mysore isolates in Richard s media. Whereas in Czapek s media least growth was observed in lactose. The utilization of various carbon compounds may depend on either the activity of the fungus to utilize certain simpler forms or its power to convert the complex carbon compounds into simpler forms, which may be easily utilized. Sucrose was found to be the better carbon source than any other carbon source tested for Fusarium oxysporum f. sp. cubense. Sucrose being the major component of photosynthesis in plants is generally utilized as a good carbon source by most of the plant pathogenic fungi. The present results corroborate with the finding of Moore and Chupp (1952) reported that all the three isolates of Fusarium oxysporum f. sp. lycopercisi, Fusarium oxysporum f. sp. conglutinans and Fusarium oxysporum f. sp. were able to utilize a number of carbon sources and hydrolysed starch. Naik et al. (2010) reported that all carbon sources used were suitable for 5

7 the growth of Fusarium oxysporum f. sp. vanilla isolates. However, growth of isolates was best on sucrose followed by fructose and maltose with mean maximum growth of 60.0, 57.0 and 56.9 mm respectively. Ramteke and Kamble (2011) reported that five carbon sources (sucrose, dextrose, fructose, maltose and lactose) were incorporated in czapek s dox agar medium among them sucrose was found to be the best carbon source for the growth of Fusarium solani. It was followed by lactose, maltose, dextrose and fructose. REFERENCES 1. Lilly V G and Barnett H L (1951), Physiology of Fungi, pp , Mc-Graw Hill Book Co. Inc., London, UK. 2. Moore H and Chupp C (1952), A Physiological Study of the Fusaria Causing Tomato, Cabbage and Muskmelon Wilts, Mycologia, Vol. 44, pp Naik G B, Nagaraja R, Basavaraja M K and Naik K R (2010), Variability Studies of Fusarium oxysporum f. sp. Vanillae s, Int. J. Sci. Nature, Vol. 1, No. 1, pp Ramteke P K and Kamble S S (2011), Physiological Studies in Fusarium Solani Causing Rhizome Rot of Ginger ( Zinger officinale Rosc.), Int. Quat. J. Life. Sci., Vol. 6, No. 2, pp Thangavelu R, Sundararaju P, Sathiamoorthy S, Raguchander T, Velazhahan R, Nakkeeran S and Palaniswami A (2001), Status of Fusarium Wilt of Banana in India, in Molina A B, Nikmasdek N H and Liew K W (Eds.), Banana Fusarium Wilt Management Towards Sustainable Cultivation, pp , INIBAP-ASPNET, Los Banos, Laguna, Philippines. 6

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