Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-24T16:24:18.640Z Has data issue: false hasContentIssue false

Seed dormancy in four Tibetan Plateau Vicia species and characterization of physiological changes in response of seeds to environmental factors

Published online by Cambridge University Press:  01 February 2013

Xiaowen Hu*
Affiliation:
State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730020, China
Tingshan Li
Affiliation:
State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730020, China
Juan Wang
Affiliation:
State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730020, China
Yanrong Wang
Affiliation:
State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730020, China
Carol C. Baskin
Affiliation:
Department of Biology, University of Kentucky, Lexington, Kentucky 40506-0225, USA Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546-0312, USA
Jerry M. Baskin
Affiliation:
Department of Biology, University of Kentucky, Lexington, Kentucky 40506-0225, USA
*
*Correspondence. Fax: 86-0931-8914043. E-mail: [email protected]

Abstract

Although seed dormancy of temperate legumes is well understood, less is known about it in species that grow in subalpine/alpine areas. This study investigated dormancy and germination of four Vicia species from the Tibetan Plateau. Fresh seeds of V. sativa were permeable to water, whereas those of V. angustifolia, V. amoena and V. unijuga had physical dormancy (PY). One year of dry storage increased the proportion of impermeable seeds in V. angustifolia, but showed no effect on seed coat permeability in V. amoena or V. unijuga. Seeds of all four species also had non-deep physiological dormancy (PD), which was especially apparent in the two annuals at a high germination temperature (20°C). After 1 year of storage, PD had been lost. The hydrotime model showed that fresh seeds obtained a significantly higher median water potential [Ψb(50)] than stored seeds, implying that PD prevents germination in winter for seeds dispersed without PY when water availability is limited. After 6 months on the soil surface in the field, a high proportion of permeable seeds remained ungerminated, further suggesting that PD plays a key role in preventing germination after dispersal. Addition of fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, evened-out the differences in germination between fresh and stored seeds, which points to the key role of ABA biosynthesis in maintaining dormancy. Further, fresh seeds were more sensitive to exogenous ABA than stored seeds, indicating that storage decreased embryo sensitivity to ABA. On the other hand, the gibberellic acid GA3 increased germination rate, which implies that embryo sensitivity to GA is also involved in seed dormancy regulation. This study showed that PY, PD or their combination (PY+PD) plays a key role in timing germination after dispersal, and that different intensities of dormancy occur among these four Vicia species from the Tibetan Plateau.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 2013 

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

Alvarado, V. and Bradford, K.J. (2002) A hydrothermal time model explains the cardinal temperatures for seed germination. Plant, Cell and Environment 25, 10611069.CrossRefGoogle Scholar
Amen, R.D. (1966) Extent and role of seed dormancy in alpine plants. Quarterly Review of Biology 41, 271281.CrossRefGoogle Scholar
Baskin, C.C. and Baskin, J.M. (1998) Seeds: ecology, biogeography and evolution of dormancy and germination. San Diego, Academic Press.Google Scholar
Baskin, J.M. and Baskin, C.C. (2004) A classification system for seed dormancy. Seed Science Research 14, 116.CrossRefGoogle Scholar
Bolingue, W., Ly Vu, B., Leprince, O. and Buitink, J. (2010) Characterization of dormancy behaviour in seeds of the model legume. Seed Science Research 20, 97107.CrossRefGoogle Scholar
Bradford, K.J. (1990) A water relations analysis of seed germination rates. Plant Physiology 94, 840849.CrossRefGoogle ScholarPubMed
Bradford, K.J. (1995) Water relations in seed germination. pp. 351396in Kigel, J.; Galili, G. (Eds) Seed development and germination. New York, Marcel Dekker.Google Scholar
Cheng, Z. and Bradford, K.J. (1999) Hydrothermal time analysis of tomato seed germination responses to priming treatment. Journal of Experimental Botany 50, 8999.CrossRefGoogle Scholar
da Silva, E.A.A., Toorop, P.E., Nijsse, J., Bewley, J.D. and Hilhorst, H.W.M. (2005) Exogenous gibberellins inhibit coffee (Coffea arabica cv. Rubi) seed germination and cause cell death in the embryo. Journal of Experimental Botany 56, 10291038.CrossRefGoogle ScholarPubMed
Ellis, R.H., Covell, S., Roberts, E.H. and Summerfield, R.J. (1986) The influence of temperature on seed germination rate in grain legumes. II. Intraspecific variation in chickpea (Cicer arietinum L.) at constant temperature. Journal of Experimental Botany 37, 15031515.CrossRefGoogle Scholar
Finch-Savage, W.E. and Leubner-Metzger, G. (2006) Seed dormancy and the control of germination. New Phytologist 171, 501523.CrossRefGoogle ScholarPubMed
Gummerson, R.J. (1986) The effect of constant temperatures and osmotic potential on the germination of sugarbeet. Journal of Experimental Botany 37, 729741.CrossRefGoogle Scholar
Hu, X.W., Wu, Y.P. and Wang, Y.R. (2009) Different requirements for physical dormancy release in two populations of Sophora alopecuroides relation to burial depth. Ecological Research 24, 10511056.CrossRefGoogle Scholar
Hu, X.W., Wang, J. and Wang, Y.R. (2012) Thermal time model analysis for seed germination of four Vicia species. Chinese Journal of Plant Ecology 36, 841848(in Chinese with English abstract).CrossRefGoogle Scholar
Kigel, J. (1995) Seed germination in arid and semi–arid regions. pp. 645700in Kigel, J.; Galili, G. (Eds) Seed development and germination. New York, Marcel Dekker.Google Scholar
Körner, C. (2003) Alpine plant life: functional plant ecology of high mountain ecosystems (2nd edition). Berlin–Heidelberg, Springer.CrossRefGoogle Scholar
Michel, B.E. and Kaufmann, M.R. (1973) The osmotic potential of polyethylene glycol 6000. Plant Physiology 51, 914916.CrossRefGoogle ScholarPubMed
Nie, B. (2011) Characters of hard seed formation and release, methods for hard seed breaking in Vicia unijuga. Masters thesis, Lanzhou University (in Chinese with English abstract).Google Scholar
Norman, H.C., Cocks, P.S., Smith, F.P. and Nutt, B.J. (1998) Reproductive strategies in Mediterranean annual clovers: germination and hardseededness. Australian Journal of Agricultural Research 49, 973982.CrossRefGoogle Scholar
Qu, X., Baskin, J.M. and Baskin, C.C. (2010) Whole-seed development in Sicyos angulatus (Cucurbitaceae, Sicyeae) and a comparison with the development of water-impermeable seeds in five other families. Plant Species Biology 258, 185192.CrossRefGoogle Scholar
Thomson, J.R. (1965) Breaking dormancy in germination tests of Trifolium spp. Proceedings of the International Seed Testing Association 30, 905909.Google Scholar
Tran, V.N. and Cavanagh, A.K. (1984) Structural aspects of dormancy. pp. 144in Murray, D.R. (Ed.) Germination and reserve mobilization. Sydney, Academic Press.Google Scholar
Trudgill, D.L., Squire, G.R. and Thompson, K. (2000) A thermal time basis for comparing the germination requirements of some British herbaceous plants. New Phytologist 145, 107114.CrossRefGoogle Scholar
Van Assche, J.A. and Vandelook, F. (2010) Combinational dormancy in winter annual Fabaceae. Seed Science Research 20, 237242.CrossRefGoogle Scholar
Wang, M.Y., Liu, W., Liu, K. and Bu, H.Y. (2011) The base temperature and the thermal time requirement for seed germination of 10 grass species on the eastern Qinghai-Tibet plateau. Pratacultural Science 28, 983987(in Chinese with English abstract).Google Scholar
Wang, Y.R., Nan, Z.B., Nie, B., Zhang, J.Q. and Zhang, J.Y. (2005) Distinct comparison of morphological characteristics for several new cold resistant Vicia sativa lines. Acta Prataculture Sinica 14, 2832(in Chinese with English abstract).Google Scholar