Abstract:
Taxus chinensis var. mairei is a rare and endangered medicinal plant species distributed
in China. In order to promote fast propagation and preserve the natural resources,
conditions for in vitro germination and seedling development of embryos of T. chinensis
var. mairei from Anhui or Zhejiang were investigated. Results showed that in vitro
germination rate of excised embryos cultured under 14 hours photoperiod was higher
than that in darkness. But, nearly all embryos germinated under 14 hours photoperiod
failed to develop into seedlings. Comparatively, 23.3 and 36.3% of embryos from Anhui
and Zhejiang, respectively, which germinated in darkness, developed into full seedlings.
Addition of plant growth regulators [gibberellic acid (GA3
), indole-3-acetic acid (IAA), 6-
benzylaminopurine (BA)] and organic additives (casein hydrolysate and yeast extract) in
mediums promoted germination and seedling development. (Woody plant medium) WPM
medium supplemented with 0.5 mg L-1 GA3
, 0.5 mg L-1 IAA, 0.5 mg L-1 BA and 1 g L-1
activated charcoal was optimal for the culture of embryos from Anhui, while WPM
medium supplemented with 0.5 mg L-1 GA3
, 500 mg L-1 casein hydrolysate and 1 g L-1
activated charcoal was optimum for embryos from Zhejiang. Moreover, the germination
and seedling survival rate of embryos of T. chinensis var. mairei decreased with increasing
maturity of the seeds. In conclusion, darkness during germination is necessary for
subsequent seedling development and immature seeds are optimal for embryo culture of
this species.
Keywords: Embryo culture, Germination, In vitro culture, Seedling development, Taxus.