Understanding seed dormancy and germination aids conservation of rainforest species from tropical montane cloud forest: a case study confirming morphophysiological dormancy in the genus Tasmannia
Journal Publication ResearchOnline@JCUAbstract
Context: Seed dormancy is one issue hindering implementation of conservation actions for rainforest species. Aims: We studied dormancy and germination in Tasmannia sp. Mt Bellenden Ker and Tasmannia membranea, two tropical montane rainforest species threatened by climate change, to develop a better understanding of dormancy in the species and the genus. Methods: Dormancy was classified for T. sp. Mt Bellenden Ker on the basis of an imbibition test, analysis of embryo to seed length (E:S) ratios and germination in response to the following four dormancy-breaking treatments: (I) scarification of the seedcoat near the micropylar end; (2) removal of the seedcoat; (3) application of 100 mg L(-1)or (4) 500 mg L-1 gibberellic acid. The most effective treatment was then tested on T. membranea. The requirement for light for germination was also assessed. Key results: Both scarified and intact seeds imbibed water. Initial E:S ratios were <0.22 for both species and increased up to 0.74 after 40 days, just before radicle emergence, for T. sp. Mt Bellenden Ker. Germination proportions were significantly higher in Treatments 1 and 2 than the remaining treatments for T. sp. Mt Bellenden Ker; T. membranea responded similarly well to Treatment 1. Germination under alternating light/dark conditions was slightly, but not significantly, greater than germination in the dark alone. Conclusions: Both species have morphophysiological dormancy and treatments that remove seedcoat resistance to embryo growth facilitate germination. These treatments may improve germination in other species from the genus Tasmannia. Implications: This knowledge will aid the germination of seeds to implement conservation strategies for Tasmannia spp.
Journal
Australian Journal of Botany
Publication Name
N/A
Volume
70
ISBN/ISSN
1444-9862
Edition
N/A
Issue
6
Pages Count
10
Location
N/A
Publisher
CSIRO Publishing
Publisher Url
N/A
Publisher Location
N/A
Publish Date
N/A
Url
N/A
Date
N/A
EISSN
N/A
DOI
10.1071/BT22011