Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-27T09:47:03.306Z Has data issue: false hasContentIssue false

Morphophysiological seed dormancy in Heptacodium

Published online by Cambridge University Press:  26 February 2018

Robert L. Geneve*
Affiliation:
Department of Horticulture, University of Kentucky, Lexington, KY 40546, USA
Sharon T. Kester
Affiliation:
Department of Horticulture, University of Kentucky, Lexington, KY 40546, USA
*
Author for correspondence: Robert L. Geneve, Email: RGeneve@uky.edu

Abstract

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.

Type
Research Paper
Copyright
Copyright © Cambridge University Press 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baskin, JM and Baskin, CC (2004) A classification system for seed dormancy. Seed Science Research 14, 116.Google Scholar
Baskin, JM, Hidayati, SN, Baskin, CC, Walck, JL, Huang, Z and Chien, C (2006) Evolutionary considerations of the presence of both morphophysiological and physiological seed dormancy in the highly advanced euasterids II order Dipsacales. Seed Science Research 16, 233242.Google Scholar
DeMason, DA, Stillman, JI and Ellmore, GS (1989) Acid phosphatase localization in seedling tissues of the palms, Phoenix dactylifera and Washingtonia filifera, and its relevance to controls of germination. Canadian Journal of Botany 67, 11031110.Google Scholar
Dirr, MA and Heuser, CW (2006) The Reference Manual of Woody Plant Propagation. From Seed to Tissue Culture, 2nd edn. North Carolina: Varsity Press.Google Scholar
Finneseth, CH, Layne, DR and Geneve, RL (1998) Morphological development of the North American pawpaw during germination and seedling emergence. HortScience 33, 802805.Google Scholar
Hidayati, SN, Baskin, JM and Baskin, CC (2000a) Dormancy-breaking and germination requirements for seeds of Diervilla lonicera (Caprifoliaceae), a species with underdeveloped linear embryos. Canadian Journal of Botany 78, 11991205.Google Scholar
Hidayati, SN, Baskin, JM and Baskin, CC (2000b) Dormancy-breaking and germination requirements of seeds of four Lonicera species (Caprifoliaceae) with underdeveloped spatulate embryos. Seed Science Research 10, 459469.Google Scholar
Hidayati, SN, Baskin, JM and Baskin, CC (2001). Dormancy-breaking and germination requirements for seeds of Symphoricarpos orbiculatus (Caprifoliaceae). American Journal of Botany 88, 14441451.Google Scholar
Jacobs, B, Lens, F and Smets, E (2009) Evolution of fruit and seed characters in the Diervilla and Lonicera clades (Caprifoliaceae, Dipsacales). Annals of Botany 104, 253276.Google Scholar
Jacobsen, JV and Pressman, E (1979) A structural study of germination in celery (Apium graveolens L.) seed with emphasis on endosperm breakdown. Planta 144, 241248.Google Scholar
Jin, Z and Li, J (2007) Genetic differentiation in endangered Heptacodium miconoides Rehd. based on ISSR polymorphism and implications for its conservation. Forest Ecology and Management 245, 130136.Google Scholar
Koller, GL (1986) Seven-son flower from Zhejiang: introducing the versatile ornamental shrub Heptacodium jasminoides Airy Shaw. Arnoldia 46, 214.Google Scholar
Lee, CC and Bilderback, TE (1990) Propagation of Heptacodium jasminoides Airy-Shaw by softwood and semi-hardwood cuttings. Journal of Environmental Horticulture 8, 121123.Google Scholar
Pinheiro, CUB (2001) Germination strategies of palms: the case of Schippia concolor Burret in Belize. Brittonia 53, 519527.Google Scholar
Rosner, LS, Harrington, JT, Dreesen, DR and Murray, L (2002) Effect of gibberellic acid and standard seed treatments on mountain snowberry germination. Native Plants Journal 3, 155162.Google Scholar
Scheiber, SM and Robacker, CD (2003) Effect of pericarp removal, gibberellic acid treatment, and stratification on seed germination of Abelia x grandiflora. Journal of Environmental Horticulture 21, 3437.Google Scholar