Heptacodium miconiodes is an endangered, monotypic genus in the Caprifoliaceae endemic to China. Species within the Caprifoliaceae have been shown to have morphological or morphophysiological dormancy. Heptacodium seeds had an underdeveloped embryo at the time of fruit dispersal with an embryo that occupied approximately 12% of the seed length. Cold (8 weeks at 5°C) and warm (8 weeks at 20°C) stratification was effective for dormancy release, but embryo growth prior to germination only occurred at warm temperatures (20°C). Gibberellic acid treatment partially substituted for cold stratification. Final seed germination percentage was not different after warm or cold stratification; however, seeds initially exposed to cold stratification germinated faster and more uniformly. Cold stratified seeds reached 50% final germination approximately 55 days sooner than warm stratified seeds. Prior to radicle emergence, embryos grew to fill approximately 60% of the seed through an endosperm channel that occupied the centre portion of the endosperm. Cells in the endosperm channel had thinner cell walls and fewer storage vesicles compared with other endosperm cells. Channel cells formed a dissolution zone ahead of embryo elongation assumed to be involved with enzymatic hydrolysis of storage reserves. Based on these results, it was concluded that Heptacodium displays the characteristics of seeds with non-deep simple morphophysiological dormancy.
|Number of pages||5|
|Journal||Seed Science Research|
|State||Published - Sep 1 2018|
Bibliographical noteFunding Information:
This is publication no. 17-11-057 of the Kentucky Agricultural Experiment Station and is published with the approval of the Director. This project was supported by the USDA National Institute of Food and Agriculture, hatch project number KY011042.
© Cambridge University Press 2018.
- endosperm channel cells
- seven son's tree
- under-developed embryo
ASJC Scopus subject areas
- Plant Science