Ruangwut Chutima

Chiang Mai University, Chiang Mai, Chiang Mai Province, Thailand

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Publications (3)5.17 Total impact

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    ABSTRACT: Eight endophytic fungi were isolated from roots of the threatened terrestrial orchid, Pecteilis susannae (L.) Rafin. Phylogenetic analysis based on an alignment of internal transcribed spacer regions of nuclear rDNA indicated that seven isolates belonged to the genus Epulorhiza and one to Fusarium. All fungal isolates were cultured with orchid seeds collected from three field sites near Doi Suthep-Pui National Park, Chiang Mai, Thailand. Seed germination and protocorm development were evaluated up to 70 days after sowing. Percent symbiotic seed germination was highest (86.2%) when seeds were cultured with Epulorhiza (CMU-Aug 013). The protocorm development was the most advanced up to stage 2, continued embryo enlargement, or rupture of the testa, and the highest percentage was 17.8% when seeds were cultured with Epulorhiza (CMU-Aug 007). Without fungi, seed germination and protocorm development were 62.1% and 11.1%, respectively. The dependency of P. susannae on fungal symbionts for early seedling development is yet to be determined. Optimizing seed germination and seedling fitness will assist the conservation of this threatened orchid in Thailand.
    Mycorrhiza 04/2011; 21(3):221-9. · 2.96 Impact Factor
  • Ruangwut Chutima, Saisamorn Lumyong
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    ABSTRACT: Thirteen endophytic fungi were isolated from roots of three orchid species, Spathoglottis affinis, Paphiopedelum bellatulum and Phaius tankervilleae. Of these, three fungal isolates produced high levels of indole-3-acetic acid (IAA) in culture medium supplemented with 2 mg/ml of L-tryptophan, and were selected for further analysis. Morphological characteristics and a phylogenetic analysis based on an alignment of internal transcribed spacer regions of nuclear rDNA indicated that the fungal isolates CMU-SLP 007 and CMU-NUT 013 belonged to family Tulasnellaceae, genus Tulasnella (the anamorphic genus Epulorhiza) and the fungal isolate CMU-AU 006 belonged to Colletotrichum gloeosporioides. These three fungal isolates produced maximum levels of IAA when grown in a culture medium supplemented with 4 mg/ml of L-tryptophan (C. gloeosporioides CMU-AU 006, 243.56 μg/ml and Tulasnella sp. CMU-SLP 007, 155.63 μg/ml) and 6 mg/ml of L-tryptophan (Tulasnella sp. CMU-NUT 013, 104.03 μg/ml). Thin layer chromatography revealed that all fungal IAA presented the same Rf value as the standard IAA. The biological activity of fungal IAA showed that it increased the length of stem forming roots and the number of roots of kidney bean (Phaseolus vulgaris), promoted seed germination, the length of roots and root to shoot ratio of corn (Zea mays) and increased the elongation of rice (Oryza sativa) coleoptiles when compared with all controls (water and culture medium treatments). In addition, the results of all biological activities using fungal IAA indicated that the quality of fungal IAA were similar to standard IAA.
    Symbiosis 56(1). · 1.11 Impact Factor
  • Ruangwut Chutima, Bernard Dell, Saisamorn Lumyong
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    ABSTRACT: Symbiotic seed germination of Pecteilis susannae (L.) Rafin was investigated using 11 fungal isolates recovered from roots of four Thai terrestrial orchids (P. susannae, Eulophia spectabilis, Paphiopedilum bellatulum and Spathoglottis affinis). Seed germination and protocorm development were evaluated up to 133days after sowing. Protocorm development was most advanced, up to stage 5 (elongation of the first leaf), when seeds were cultured with 4 Epulorhiza isolates obtained from roots of P. susannae (CMU-Aug 028, 4.3%, CMU-Aug 007, 4.2%, and CMU-Aug 013, 2.2%) and E. spectabilis (CMU-STE 014, 3.9%). Moreover, stage 4 protocorm development (emergence of the first leaf) occurred with fungal isolates CMU-STE 011, 5.7%, (Epulorhiza sp.) and CMU-AU 212, 4.3%, (Tulasnella sp.) obtained from roots of E. spectabilis and S. affinis respectively. When seed was incubated without fungi (control), development was limited to stage 3 of protocorm development (appearance of promeristem). This is the first report of protocorm stage 5 development in P. susannae using compatible fungal symbionts. Optimization of seed germination and seedling fitness will assist the conservation and propagation of this orchid species and other terrestrial orchids in Thailand. KeywordsEpulorhiza–Orchid mycorrhiza–Pecteilis susannae–Orchid seed germination–Terrestrial orchid
    Symbiosis 53(3):149-156. · 1.11 Impact Factor