Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba 305-0005, Japan.
Am J Bot. 2008 Dec;95(12):1645-51. doi: 10.3732/ajb.0800122. Epub 2008 Oct 31.
Trichomanes intricatum, the sporophyte-less filmy fern of the eastern United States, has been considered to be a species whose sporophyte generation has become extinct or is possibly still present among the many species of Trichomanes s.l. in the new world tropics but unable to grow in a temperate climate. A close relationship to Asian species has heretofore not been considered. Comparison of rbcL and rps4-trnS sequences to species of Trichomanes s.l. reveals that T. intricatum shares its chloroplast genome with Crepidomanes schmidtianum of eastern Asia. Because C. schmidtianum is a sterile triploid and the ploidy level of T. intricatum is unknown, several scenarios leading to their sharing of these maternally inherited genes must be explored.
美国东部缺少孢子体的绵毛蹄盖蕨，一直被认为是一种孢子体已经灭绝，或者可能仍然存在于新世界热带地区的许多蹄盖蕨属物种中，但无法在温带气候中生长的物种。迄今尚未考虑与亚洲物种的密切关系。将 rbcL 和 rps4-trnS 序列与蹄盖蕨属的物种进行比较表明，绵毛蹄盖蕨与东亚的短肠蕨共享其叶绿体基因组。由于短肠蕨是一种不育的三倍体，而绵毛蹄盖蕨的倍性水平尚不清楚，因此必须探讨导致它们共享这些母系遗传基因的几种情况。
