Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-08T04:51:05.009Z Has data issue: false hasContentIssue false

Germination of drupelets in multi-seeded drupes of the shrub Leptecophylla tameiameiae (Ericaceae) from Hawaii: a case for deep physiological dormancy broken by high temperatures

Published online by Cambridge University Press:  22 February 2007

Carol C. Baskin*
Affiliation:
Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA Department of Plant and Soil Science, University of Kentucky, Lexington, KY 40546-0312, USA
Jerry M. Baskin
Affiliation:
Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA
Alvin Yoshinaga
Affiliation:
Center for Conservation Research and Training, 3050 Maile Way, Gilmore, 409, Honolulu, HI 96822-2279, USA
Ken Thompson
Affiliation:
Department of Animal and Plant Sciences, The University, Sheffield, S10 2TN, UK
*
*Correspondence: Fax: +1 859 257 1717 Email: [email protected]

Abstract

This study addressed the difficulty of germinating drupelets (hereafter seeds) in the multi-seeded stony dispersal units (drupes) of Leptecophylla tameiameiae (Ericaceae). Embryos in fresh seeds were 77% the length of the endosperm, and seeds inside the intact drupes imbibed water. We monitored germination at 15/6, 20/10 and 25/15°C for 162 weeks, after which each drupe was cut open and ungerminated seeds counted. Drupes contained 1–6 seeds, and the total number of seeds in all treatments and controls was 1977, with 20, 29, 25, 18, 7 and <1% of them occurring in one-, two-, three-, four-, five- and six-seeded drupes, respectively. The percentage of seeds germinating in one-, two-, three-, four-, five- and six-seeded drupes was 74, 66, 65, 72, 56 and 0, respectively. Neither warm nor cold stratification for 6 or 12 weeks significantly increased germination percentages, compared to controls incubated continuously at 25/15°C for 162 weeks, where 72% of the seeds in the drupes germinated. At 25/15°C, 24–49 weeks were required for 20% of the seeds to germinate. Warm followed by cold stratification did not promote germination, and there was no widening of the temperature range for germination. Like seeds of other species known to have deep physiological dormancy (PD), those of L. tameiameiae required extended periods of time (16 to ≥162 weeks) to come out of dormancy and germinate, gibberellic acid (GA3) did not promote germination and excised embryos failed to grow. Thus, we conclude that seeds of L. tameiameiae have deep PD. However, unlike seeds of other species with deep PD, those of L. tameiameiae required an extensive period of warm rather than of cold stratification to come out of dormancy. It is suggested that a subtype a (seeds require a long period of cold stratification to come out of dormancy) and a subtype b (seeds require a long period of exposure to warm stratification to come out of dormancy) of deep PD be recognized in the Nikolaeva formula system for classifying seed dormancy.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2005

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

Angiosperm Phylogeny Group (2003) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II. Botanical Journal of the Linnean Society 141, 399436.CrossRefGoogle Scholar
Baskin, C.C. and Baskin, J.M. (1998) Seeds: Ecology, biogeography, and evolution of seed dormancy and germination. San Diego, Academic Press.Google Scholar
Baskin, C.C., Zackrisson, O. and Baskin, J.M. (2002) Role of warm stratification in promoting germination of seeds of Empetrum hermaphroditum (Empetraceae), a circumboreal species with a stony endocarp. American Journal of Botany 89, 486493.CrossRefGoogle ScholarPubMed
Baskin, J.M. and Baskin, C.C. (2004) A classification system for seed dormancy. Seed Science Research 14, 116.CrossRefGoogle Scholar
Carlquist, S. (1974) Island biology. New York, Columbia University Press.CrossRefGoogle Scholar
Criley, R.A. (1999) Aloha Hawai'i. American Nurseryman 190, 5061.Google Scholar
Ng, F.S.P. (1991) Manual of forest fruits, seeds and seedlingsVolume one. Malayan Forest Record No. 34.Kuala Lumpur,Malaysia Forest Research Institute Malaysia..Google Scholar
Ng, F.S.P. (1992) Manual of forest fruits, seeds and seedlingsVolume one. Malayan Forest Record No. 34.Kuala Lumpur,Malaysia Forest Research Institute Malaysia.Google Scholar
Nikolaeva, M.G. (1969) Physiology of deep dormancy in seeds. Leningrad, Russia, Izdatel'stvo ‘Nauka’. [Translated from Russian by Z., Shapiro, National Science Foundation, Washington, DC.)Google Scholar
Nikolaeva, M.G. (2001) Ekologo-fiziologicheskie osobennosti pokoya i prorastaniya semyan (itogiissledovantii zaistekshee stoletie) [Ecological and physiological aspects of seed dormancy and germination (review of investigations for the last century)]. Botanicheskii Zhurnal 86, 114. (for English translation, see) http://www.seedscisoc.org.Google Scholar
Ooi, M.K.J., Auld, T.D. and Whelan, R.J. (2004) Delayed post-fire seedling emergence linked to season: a case study with Leucopogon species (Epacridaceae). Plant Ecology 174, 183196.CrossRefGoogle Scholar
Quinn, C.J., Crayn, D.M., Heslewood, M.M., Brown, E.A. and Gadek, P.A. (2003) A molecular estimate of the phylogeny of Styphelieae (Ericaceae). Australian Systematic Botany 16, 581594.Google Scholar
Stratton, L., Hudson, L., Suenaga, N. and Morgan, B. (1998) Overview of Hawaiian dry forest propagation techniques. Newsletter of the Hawaiian Botanical Society 37 2 13 1527.Google Scholar
Wagner, W.L., Herbst, D.R. and Sohmer, S.H. (1999) Manual of the flowering plants of Hawaii (revised edition). Volume 1. Honolulu, University of Hawaii Press and Bishop Museum Press.Google Scholar