SMOKE-SATURATED WATER FROM FIVE GRASSES GROWING IN JAPAN INHIBITS IN VITRO PROTOCORM-LIKE BODY FORMATION IN HYBRID CYMBIDIUM

摘要

Smoke derived from the burning of plant material has been shown to stimulate seed growth of several species. In addition, several studies have reported that when smoke is condensed with water, smoke-saturated water (SSW) can also stimulate the germination of orchid seeds. In this study, SSW was derived from burning the aerial part of five grasses growing in the wild in Shikoku, Japan ( Arundinella hirta (Thunb.) C. Tanaka var. hirta , Microstegium japonicum (Miquel) Koidzumi, Miscanthus sinensis Andersson, Paspalum thunbergii Kunth ex Steud., Themeda triandra Forssk. var. japonica (Willd.) Makino), all of which flower between August and October. SSW was added at three concentrations (1, 5, 10%, v/w) to solid, agarized Teixeira Cymbidium (TC) medium to assess the impact on in vitro organogenesis of hybrid Cymbidium , specifically on new protocorm-like body (neo-PLB) formation. The SSW of all five species strongly inhibited the formation of neo-PLBs at all concentrations relative to the control (no SSW added). Since PLBs are considered to be the equivalent of somatic embryos in orchids, and since SSW is able to stimulate the germination of zygotic embryos in other plant families, the mechanism of action is clearly different between zygotic and somatic embryos.