絶滅が危惧される菌従属栄養植物ハルザキヤツシロランとクロヤツシロランの生態的特質とリゾームの野外での生存への給水効果

概要

論文の詳細を見る
Investigated was the in situ conservation of Gastrodia nipponica and G. pubilabiata, the endangered myco-heterotrophic orchids by logging, changes of land use, or forest succession. The two orchids inhabit the bamboo forests or the evergreen broad-leaved forests in southwest of Japan. They closely resemble each other in morphology and ecol-ogy. However, G. nipponica blooms from April to May and disperses seeds until early June but G. pubilabiata blooms from October to November and disperses seeds until mid-December. An attempt to conserve G. nipponica and G. pubilabiata in situ was carried out through the water supply to their naturally occurring rhizomes using the superabsorbent polymer well absorbing water. The examination period was from mid-July, just after the end of the rainy season to October, the mid dry season. Some following ecological characteristics of the two orchids also were examined, the underground distribution of the rhizomes and its mycobionts and the symbiotic ability of some litter decomposing fungi in G. nipponica and the seasonal growth events in the two orchids. The decrease ratio in the rhizome number of G. nipponica and G. pubilabiata was low from 10 to 37% when supplied with water compared to that without water supply, respectively. The rhizomes of the two orchids inhabited the litter layer and the roots developed horizontally sticking to the litters. The mycobionts of G. nipponica formed small colonies spread-ing patchily on the soil and colonized between from the litter layer to the upper of A layer, at least 4cm in the depth. Some fungi induced germination of the seeds of G. nipponica on the agar medium containing no nutrients. The two orchids showed the similar growth stage in each season except for the fruiting. The obtained results indicate (1) the water supply after the rainy season will contribute greatly to the in situ conservation of G. nipponica and G. pubilabiata, (2) the two orchids and their mycobionts have the epiphytic life style to the litter throughout their lives, (3) the two orchids may be regulated closely by the East Asian monsoon climate, and (4) the dryness after the rainy season may be the fatal factor in the rhizome survival. Present investigation showed that G. nipponica and G. pubilabiata had the close association with the litter layer as the habitat and the litter decomposing fungi as the symbiont partners. The rhizomes and the litter were sewed together through the symbiont mycelia threads to form an ecological system. We designate such orchids as "litter layer inhabiting plant".菌従属栄養植物のハルザキヤツシロランとアキザキヤツシロランの発生地での保存について研究した｡日本版レッド
2010-03-01

絶滅が危惧される菌従属栄養植物ハルザキヤツシロランとクロヤツシロランの生態的特質とリゾームの野外での生存への給水効果

スポンサーリンク

概要

著者

関連論文

スポンサーリンク