GERMINATION OF THREE ANNUAL MEDICS (MEDICAGO ROMAN.) AS AFFECTED BY SEED-COAT DORMANCY BREAKING TECHNIQUES

Article Id: ARCC517 | Page : 112-118
Citation :- GERMINATION OF THREE ANNUAL MEDICS (MEDICAGO ROMAN.) AS AFFECTED BY SEED-COAT DORMANCY BREAKING TECHNIQUES.Legume Research-An International Journal.2012.(35):112-118
Hossein Sadeghi and Nazila khaef sadeghih@shirazu.ac.ir
Address : College of Agriculture, Shiraz University, Shiraz, Iran

Abstract

Medicago scutellata, Medicago rigidula and Medicago polymorpha are all lucern species. These are annual forage legumes of specific interest to agriculture in Mediterranean pasture. As with other legumes these have a state of seed dormancy, which delays and reduces germination. This research studied germination of these plants in response to mechanical, physical and chemical scarification to break dormancy. The rapid germination in almost all the seeds in the test was achieved from hand scarification with sandpaper, and this demonstrated that dormancy was exclusively imposed by the seed coat (hardseededness). Soaking in hot water partially removed coat-imposed dormancy in these species, but in M. scutellata even after 2 min at 100°C 97.9% of seeds still remained hard. Low temperature by keeping in refrigerator was also effective in stimulating final germination and a good rate of germination in seeds of M. scutellata and M. polymorpha. After 10 days freezing the germination rate increased by 90%. There was also a good result from keeping seeds on surface run off, after 7 days there was 90% germination rate in seeds of M. scutellata. Chemical scarification with sodium hypochlorite was also used effectively to reduce hardseededness at the lowest concentration (2%) and the shortest time (2 min) in seeds of
M. rigidula.

Keywords

Medicago scutellata Medicago rigidula Medicago polymorpha Dormancy Seed germination.

References

  1. Argel, P.J., Paton, C.J., (1999). Overcoming legume hardseededness. In: Loch, D.S., Ferguson, J.E. (Eds.), Forage Seed Production: Tropical and Subtropical Species, vol. 2. CAB International, Wallingford, pp. 247-265.
  2. Beale, P.E., Lahlou, A., Bounejmate, M., (1991). Distribution of wild annual legume species in Morocco and relationship with soil and climatic factors. Aust. J. Agric. Res. 42:1217-1230.
  3. Bewley, J.D., Black, M., (1978). Physiology and biochemistry of seeds in relation to germination. Vol. II: viability, dormancy and environmental control. Springer, Berlin.
  4. Brant, R.E., McKee, G.W., Cleveland, R.W., (1971). Effect of chemical and physical treatment on hard seed of Penngift crownvetch. Crop Sci. 11:1-6.
  5. Chebouti, A., Abdelguerfi, A., (1999). Study on the behaviour of 48 Medicago orbicularis (L.) Bart populations in two agroecological areas: interaction with the site of origin. In: Etienne, M. (Ed.), Dynamics and Sustainability of Mediterranean Pastoral Systems. CIHEAM-IAMZ, Zaragoza, pp. 103-105.
  6. Conway, N.J., Brandon, N.J., Clem, R.L., Jones, R.M., Robertson, B.A., Willcocks, J.R., (2001). Growth and
  7. persistence of 17 annual medics (Medicago spp.) accession on clay soils in central Queensland. Tropical Grassland 35:226-234.
  8. Derkaoui, M., Caddel, J.L., Rommann, L.L., (1993). Forage quality in annual Medicago spp. Agricoltura Mediterranea 123;86-91.
  9. Ehrman, T., Cocks, P.S., (1990). Ecogeography of annual legumes in Syria: distribution patterns. J. App. Ecol.
  10. 27:578-591.
  11. Hardegree, S.P., Emmerich, W.E., (1991). Variability in germination rate among seed lots of Lehmann lovegrass. J. Range Management. 44:323-326.
  12. Iban ez, A.N., Passera, C.B., (1997). Factors affecting the germination of albaida (Antyllis cytisoides L.), a forage legume of the Mediterranean coast. J. Arid Environ. 35:225-231.
  13. ISTA, 1999. International rules for seed testing. Seed Science & Technology 27 (Suppl.), 1-333.
  14. Jha, S.S., Pal, A., 1992. Seed structure in Medicago L. Flora. 187:209-218.
  15. Krugman, A., Howieson, J.G., Nutt, B.J., Carr, S.J., (1974). A second generation of annual pastures legumes and their potential for inclusion in Mediterranean-type farming systems. Aust. J. Exp. Agric., 45:289-299.
  16. Lodge, G.M., 1996. Seedling emergence and survival of annual pasture legumes in northern New South Wales. Australian Journal Agricultural Research 47:559-574.
  17. Lodge, G.M., Whalley, R.D.B., 2002. Fate of annual pasture legume seeds on a two-way thermogradient plate.
  18. Rangeland J. 24:227-241.
  19. Meloni, M.C., Piluzza, G., Bullitta, S., 2000. The potential role of alternative legumes from Asinara Island for multiple uses in difficult environments. In: Sulas, L. (Ed.), Legumes for Mediterranean Forage Crops, Pastures and Alternative Uses. Ciheam-Iamz, Zaragoza, pp. 427-430.
  20. Patane , C., Bradford, K.J., 1993. Seed dormancy in two Medicago species typical of natural pastures of Ragusa Plateau. Rivista di Agronomia. 4:412-418.
  21. Pritchard, H.W., Manger, K.R., Prendergast, F.G., (1988). Changes in Trifolium arvense seed quality following alternating temperature treatment using liquid nitrogen. Annals of Botany 62:1.
  22. Scott, S.J., Jones, R.A., Williams, W.A., (1984). Review of data analysis methods for seed germination. Crop Sci. 24:1192-1198.
  23. Snedecor, G.W., Cochran, W.G., (1989). Statistical Methods, eighth ed. Iowa State University Press, Ames, IA.
  24. Sy, A., Grouzis, M., Danthus, P., (2001). Seed germination of seven Sahelian legume species. J. Arid Environ.
  25. 49:875-882.
  26. Taiz, L., Zeiger, E., (2002). Plant Physiology, Chapter 23. Abscisic Acid: A seed maturation and antistress signal, 3rd ed. Sinauer Association, Inc., Sunderland, MA, pp. 538-558.
  27. Uzun, F., Aydin, I., (2004). Improving germination rate of Medicago and Trifolium species. Asian J. Plant Sci.
  28. 3:714-717.
  29. Van Assche, J.A., Debucquoy, K.L.A., Rommens, W.A.F., (2003). Seasonal cycles in the germination capacity of buried seeds of some Leguminosae (Fabaceae). New Phytologist 158:315-323.
  30. Zhu, Y., Sheaffer, C.C., Barnes, D.K., 1996. Forage yield and quality of six annual Medicago species in the north-central USA. Agron. J. 88:955-960.

Global Footprints