From spore germination to gametophyte development: the culture, propagation and anatomical protonemal structure of Takakia lepidozioides (Bryophyta) in Tibet Plateau

Run-Jie ZHANG, Wen-Jie PENG, Wei-Zhong LIU, Xue-Dong LI & Yi-Kun HE

en Cryptogamie, Bryologie 37 (4) - Pages 383-397

Published on 28 October 2016

Takakia lepidozioides is a rare and potentially relictual species of a genus that diverged early in the evolution history of mosses. Plants of Takakia grow very slowly in the wild and are almost too small (only ~ 5 mm high) to be genetically manipulated. We collected Takakia plants with mature spore-bearing capsules from the Nyingchi region at about 4,000 meters elevation in the Tibetan Plateau. We analyzed the pH and inorganic elements of the soil below the population to then optimize the composition of the Beneck medium that is generally suitable for moss culture. We explored the effects of several factors on spore germination and gametophyte growth and established the conditions for efficient spore germination and rapid gametophyte propagation. The characterization of spore germination and early gametophyte development revealed that the sporeling of Takakia is thalloid as in Sphagnum and Andreaea. These results provide the foundation to facilitate genetic, physiological and biochemical research with T. lepidozioides and also developmental studies, which may contribute to our understanding of the morphological transformations in the early diversification of mosses.

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