Abstract

Well differentiated gametophytes of Philonotis thwaitesii Mitt., an acrocarpous moss and Brachythecium plumosum (Hedw.) B.S.G., a pleurocarpous moss have been raised in vitro by inoculating their spores into a range of concentrations of inorganic media. Half-strength Knop’s macronutrients + Nitsch’s trace elements with 10 ppm ferric citrate was found the most suitable for growth and multiplication of these species in continuous light of 4,000-5,500 lux and at 21 ± 2ºC temperature. Protonemal buds developed on caulonema in P. thwaitesii while on chloronema in B. plumosum. Sucrose stimulated caulonemal differentiation, abundant rhizoid production and a few but much robust gametophyte development. Emergence of hyaline rhizoids like filaments has been observed in P. thwaitesii upon contact of gametophores with solid substratum while true rhizoids all along the length of gametophytes of B. plumosum emerges upon placing them horizontally on culture medium. Variable growth forms (weft-like branched as well as erect unbranched habit) have been observed in both species in culture conditions. Sub-culturing of P. thwaitesii gave rise to new population via passing through chloronemal and caulonemal stage while B. plumosum directly regenerated into new gametophytes by-passing protonemal stage. In vitro raised plants were acclimatized and transferred to soil in order to their further proliferation.

中文摘要

本文提出一種頂生蒴苔Philonotis thwaitesii Mitt. 和另一種側生蒴苔Brachythecium plumosum (Hedw.). B.S.G. 此二種苔類植物的組織培養繁殖方式；這兩種苔類能以其孢子接種到一定濃度範圍的無機培養基中，誘導產生發育良好的配子體。實驗發現在添加有Nitsch’s trace elements 以及 10 ppm ferric citrate之1/2強度Knop’s macronutrients培養基中，以21 ± 2°C溫度及4000 – 5500 lux 連續光下培養，最適合這二個物種的生長與複製。P. thwaitesii之原絲體的芽可發育自軸絲體；而B. plumosum之原絲體的芽則發育自綠絲體。蔗糖能刺激軸絲體的分化且使豐富的假根產生，卻造成少數但較強韌的配子體發育。培養P. thwaitesii時，當其配子枝與固體基質接觸後，則發現有透明假根狀的絲狀體出現；然而培養B. plumosum時，其真正假根的出現則在其被水平放置於培養基後，假根沿著配子體長軸生長出來。在不同培養條件下，這兩個物種均能觀察到多變的生長形態（緯線狀的分枝和直立不分枝的習性）。P. thwaitesii透過綠絲體和軸絲體的繼代培養，可以促使新的群體發生；而B. plumosum則可直接藉由原絲體再生新的配子體。此兩種物種以組織栽培所培育的植物體可以被馴化，並移植到土壤中更進一步的繁殖。

Keyword: Acrocarpous moss, growth forms, in vitro propagation, pleurocarpous moss, spores.