In vitro TOLERANCE OF RICE PATHOGEN Rhizoctonia solani BY ORCHID MYCORRHIZAL FUNGI ISOLATED FROM ORCHIDS IN BRIS, SETIU WETLANDS
Keywords:BRIS, orchid, orchid mycorrhiza, Rhizoctonia solani
Rice (Oryza sativa) is a major staple food that feeds more than half of the human population in the world. However, rice production faces major loss in yield due to rice diseases including Rice Sheath Blight (RSB), which is caused by a soil-borne fungal pathogen, Rhizoctonia solani. Interestingly, the same pathogenic R. solani in rice has also been isolated from orchids and is known to form a vital symbiotic relationship, called orchid mycorrhiza. Thus, this study aims at isolating and identifying the orchid mycorrhizal fungi (OMF) present in roots of orchids at beach ridges interspersed with swales (BRIS), Setiu Wetlands and to determine their antagonistic activity towards pathogenic R. solani through dual culture bioassay. Mycorrhizal fungi were isolated from the roots of Phalaenopsis pulcherrima, Bromheadia finlaysoniana and Dendrobium crumenatum. Three isolates were identified through morphological identification to be Rhizoctonia species namely A, B and C along with one fungal isolate as Daldinia species. In vitro antagonistic test against pathogenic R. solani showed Rhizoctonia species (B) displayed the strongest anti-fungal activity with 60.46% of Percentage Inhibition of Radial Growth (PIRG) value followed by Rhizoctonia species (C) with 59.9%, Rhizoctonia species (A) with 51.02% and Daldinia species with 39.80%. This preliminary investigation shows the potential of orchid mycorrhizal fungi to be developed as a biocontrol agent.
Mosquera-Espinosa, A.T., Bayman, P., Prado, G.A., Gómez-Carabalí, A. & Otero, J.T. (2013) The double life of Ceratobasidium: orchid mycorrhizal fungi and their potential for biocontrol of Rhizoctonia solani sheath blight of rice, Mycologia, 105(1): 141-150.
Bougoure, J., Ludwig, M., Brundrett, M. & Grierson, P. 2009. Identity and specificity of the fungi forming mycorrhizas with the rare mycoheterotrophic orchid Rhizanthella gardneri. Mycological Research, 113(10): 1097-1106.
Brundrett, M. 2004. Diversity and classification of mycorrhizal associations. Biological Reviews, 79: 473-495.
Eken, C. & Demirci, E. 2004. Anastomosis groups and pathogenicity of Rhizoctonia solani and binucleate Rhizoctonia isolates from bean in Eruzum, Turkey. Journal of Plant Pathology, 86(1): 49-52.
Esser, K. & Meinhardt, F. 1984. Barrage formation in fungi. In: Linskens H.F., Heslop-Harrison J. (eds) Cellular interactions. Encyclopedia of plant physiology (New series), vol 17. Springer, Berlin, Heidelberg.
Ikeda, K., Inoue, K., Nakamura, H., Hamanaka, T., Ohta, T., Kitazawa, H. & Park, P. 2011. Genetic analysis of barrage line formation during mycelial incompatibility in Rosellinia necatrix. Fungal Biology, 115(1): 80-86.
Jamilah, M.S., Faridah, M. & Rohani, S. 2015. Setiu: More than a wetlands. In Setiu Wetland, In Setiu Wetland: Species, Ecosystem and Livelihoods,
Faridah, M., Jamilah, M.S., Jarina, M.J. & Rohani, S. (eds.). Universiti Malaysia Terengganu. 87-100 pp.
Lah, M.K.B.C., Nordin, M.N. Bin, Isa, M.B.M., Khanif, Y.M. & Jahan, M.S. 2011. Composting increases BRIS soil health and sustains rice production. Science Asia, 37(4): 291-295.
Leck, A. (1999). Preparation of lactophenol cotton blue slide mounts. Journal of Community Eye Health, 12(30): 24.
Mitchell, T.L. & Britt, E.M. 1981. A coverslip technique for preparing permanent fungus mounts. Mycopathologia, 76: 23-25.
Rahman, M.A., Begum, M.F. & Alam, M.F. 2009. Screening of Trichoderma isolates as a biological control agen t against Ceratocytis paradoxa causing pineapple disease of sugarcane. Mycobiology, 37(4): 277-285.
Rasmussen, H.N. & Rasmussen, F.N. 2009. Orchid mycorrhiza: implications of a mycophagous life style. Oikos, 118: 334-345.
Rice Knowledge Bank. 2017. Retrieved November 25, 2017, from http://www.knowledgebank.irri.org/training/fact-sheets/pest-management/diseases/item/sheath-blight
Skidmore, A.M. & Dickinson, C.H. 1976. Colony interactions and hyphal interference between Septoria nodorum and phylloplane fungi. Transactions of the British Mycological Society, 66: 57-64.
Taheri, P. & Tarighi, S. 2011. Cytomolecular aspects of rice sheath blight caused by Rhizoctonia solani. European Journal of Plant Pathology, 129: 511-28.
Warcup, J.H. & Talbot, P.H.B. 1967. Perfect states of Rhizoctonias associated with orchids. New Phytologist, 66: 631-641.
How to Cite
Any reproduction of figures, tables and illustrations must obtain written permission from the Chief Editor (email@example.com). No part of the journal may be reproduced without the editor’s permission