The Uses of Rhizoctonia Mycorrhizae As a Dry Resistance Induction of Dendrobium aggregatum Seedlings

Abstract

Orchids are cultivated by tissue culture because their seeds do not have food reserves (endosperm) for their growth. All nutrient requirements are obtained from tissue culture media. Propagation by tissue culture causes them to have no association with Rhizoctonia mycorrhizae, which are needed in their growth so that they can interfere with orchid growth both vegetatively and generatively. Rhizoctonia mycorrhizae are a group of Rhizoctonia sp. which form a mutual symbiotic association with orchids. Each orchid has a different association with Rhizoctonia mycorrhizae. At the time of association with orchids, Rhizoctonia mycorrhizae will form a peloton structure in the orchid root cortex, which supplies several nutrients needed by orchids from their environment during drought. Rhizoctonia mycorrhizae inoculation has been carried out on orchid seedlings of the same species orchids in vitro. However, Rhizoctonia mycorrhizae inoculation has never been carried out on seedlings of different species of orchid using a simpler spraying method. The success of simpler Rhizoctonia mycorrhizae inoculation on Dendrobium aggregatum seedlings might provide an understanding of the increased resistance of orchids to water stress. The materials used were isolates of Rhizoctonia mycorrhizae isolated from the roots of Dendrobium lasiantera and seedlings of Dendrobium aggregatum aged 6 months. The seedlings consisted of two groups. The former included seedlings exposed to Rhizoctonia mycorrhizae (M1) and watering with the intervals of 1, 2, and 3 days and those treated without Rhizoctonia mycorrhizae (M0) but with watering at the same intervals. The experiment used RCBD with 14 replications. Meanwhile, the control group was not exposed to both Rhizoctonia mycorrhizae and watering. The results showed that Rhizoctonia mycorrhizae inoculation had a significant effect on seedling height, leaf length, number of roots, and fresh weight of seedlings. Meanwhile, the watering interval did not give a real effect.