Delayed Growth in Mycoheterotrophic Gametophytes of Seedless Vascular Plants

Dean P. Whittier

《The American Fern Journal》 105卷1期 (2015/01) Pp. 1-10

並列摘要

Growth of the mycoheterotrophic gametophytes of Sceptridium dissectum and Ophioglossum crotolophoroides stalls at a few cells after germination on a nutrient medium lacking sugar. Resumption of growth when the cultures are supplied with glucose reveals that they are still alive. The stalled gametophytes of S. dissectum and O. crotalophoroides on media without sugar contain lipid droplets from the spores and a few starch grains that form during germination. The starch and lipid do not support the further growth of the stalled gametophytes because the size of the gametophytes does not change over time. These storage products slowly disappear from the stalled gametophytes. It appears that the storage materials are used to keep the stalled gametophytes alive. About 9% of the stalled gametophytes of O. crotalophoroides remain alive for ten months and about 5% of those of S. dissectum remain alive for 34 months. Delayed gametophyte growth is also exhibited by younggametophytes of Botrypus virginianus, Lycopodium obscurum, and Psilotum nudum. Delayed growth of mycoheterotrophic gametophytes under natural conditions would increase the time available for colonization by appropriate mycorrhizal fungi.

並列關鍵字

Ophioglossales ； Lycopodiales ； Psilotales ； mycorrhiza ； sugar-free medium