Isolation, characterization, and plant growth-promoting activities of endophytic fungi from a wild orchid Vanda cristata

Abstract

Endophytism is one of the widely explored phenomena related to orchids and fungi. Endophytic fungi assist plants by supplementing nutrient acquisition, and synthesis of plant growth regulators. Vanda cristata is an epiphytic orchid that has a great diversity of endophytic fungi. Endophytic fungi were isolated from roots, stems, and leaves of V. cristata and identified by both morphological and molecular study. Furthermore, the isolated endophytic fungi were subjected to auxin synthesis, phosphate solubilization, ammonia synthesis, and elicitor growth test for understanding their growth-promoting effect in a qualitative and quantitative manner. Altogether, 12 different endophytic fungi were isolated from roots, stems, and leaves of V. cristata of which most species belonged to Ascomycota. Unidentified II fungi were found to be most effective for auxin synthesis and phosphate solubilization while Agaricus bisporous and Mycolepto discus were most effective for ammonia synthesis. We have tested the plant growth-promoting activity of the twelve isolated endophytic fungi on Cymbidium aloifolium protocorms (12 weeks old). All the endophytic fungi showed growth-promoting activity. Plant growth of Cymbidium aloifolium was found higher on the MS medium supplemented with all fungal elicitors. Fungal elicitor CVS4, however, showed the highest plant growth-promoting activity toward C. aloifolium.

Antioxidant, anticancer and antimicrobial effects of In vitro developed protocorms of Dendrobium longicornu

“…This is because of endophytic fungi isolated from one species does not necessarily stimulate the seed germination or further development of protocorms of the other species. The elicitors used in the present study were prepared in our laboratory from the endophytic fungi of Dendrobium moniliforme and Vanda cristata [ 11 , 12 ]. However, the supplementation of elicitors on MS-medium played a vital role in seed germination, production of protocorms biomass and plant growth of Cymbidium aloifolium and Rhyncostylis retusa [ 11 , 12 ].…”

“…The elicitors used in the present study were prepared in our laboratory from the endophytic fungi of Dendrobium moniliforme and Vanda cristata [ 11 , 12 ]. However, the supplementation of elicitors on MS-medium played a vital role in seed germination, production of protocorms biomass and plant growth of Cymbidium aloifolium and Rhyncostylis retusa [ 11 , 12 ]. We wanted to develop a protocol that will lead to the production of increased phenolic and other bioactive secondary metabolites in the cultured protocorms biomass.…”

“…The seeds of the sterilized pod were transferred to the full strength of MS (Murashige and Skoog) medium supplemented with endophytic elicitors. MS medium without any additives was used as control medium [ 12 ]. Cultures were incubated in the culture room at 25 ± 2 °C, with 16 h of light.…”

“…Its wild resource has been depleted by overexploitation to meet the demand in traditional medicine. There is also difficulty in the germination of its seeds in nature without prior symbiosis with special mycorrhizal fungi [ [10] , [11] , [12] ]. Hence, it has to be found as threatened species in Appendix II of the Convention on International Trade in Endangered Species (CITES).…”

Comparative Cytotoxic Activity of Wild Harvested Stems and In Vitro-Raised Protocorms of Dendrobium chryseum Rolfe in Human Cervical Carcinoma and Glioblastoma Cell Lines

“…Its wild resource has been depleted by overexploitation to meet the demand in traditional medicine and the floriculture industry due to its beautiful flowers. Germination of its seeds in nature is very low since seed germination depends on a symbiotic relationship between the seeds and a special mycorrhizal fungus [ 20 – 23 ]. Recent decades have seen a sharp increase in the role of in vitro techniques in plant conservation efforts designed to counter the rapid decline in the world's biodiversity [ 6 , 24 , 25 ].…”