TOHUMDA DORMANSİ VE ÇİMLENME

Öz

Embriyonik radikülün tohum kabuğundan çıkmasıyla sağlanan çimlenme, dormansi sayesinde yılın en uygun döneminde gerçekleştirilir. Böylece yeni nesil genç bireylerin uygun olmayan mevsimsel şartlarda ortaya çıkması önlenerek, türün varlığını sürdürmesi ve popülasyonun yeni habitatlarına yerleşmesi de sağlanır. Tohumların yeni biyomlarına yayılma süreçlerinde ortaya çıkan anatomik, morfolojik ve fizyolojik adaptasyonlar, aynı zamanda farklı dormansi çeşitlerinin de oluşmasını sağlamıştır. Buna göre tohumlu bitkilerde görülen tüm dormansi çeşitlerini, kendi içinde seviye ve tiplerine ayrılacak şekilde beş ana sınıf altında tanımlamak mümkündür. Bunlar: Fiziksel dormansi (PY), Morfolojik dormansi (MD), Morfofizyolojik dormansi (MPD), Fizyolojik dormansi (PD) ve Kombinasyonel dormansi (PY + PD) dir.

Anahtar Kelimeler

• Tohum
• Dormansi
• Çimlenme

Dormancy and Germination in Seeds

Öz

Germination occur the emergence of the embryonic radicle from the seed testa and this is carried out in the most suitable period of the year thanks to dormancy. Thus, it is ensured that the new generation of young individuals cannot emerge in unsuitable seasonal conditions and that the species continues to exist and that the population can settle in the new habitats. The anatomical, morphological and physiological adaptations that occur in the distribution processes of the seeds to the new biomes have also resulted in the formation of dormancy kinds. Accordingly, it is possible to define all types of dormancy in seed plants under five main classes in such a way that they are divided into levels and types. These include: Physical dormancy (PY), Morphological dormancy (MD), Morphophysiological dormancy (MPD), Physiological dormancy (PD) and Combinational dormancy (PY + PD).

Anahtar Kelimeler

• Seed
• Dormancy
• Germination

Kaynakça

1. Ashikawa I, Abe F, Nakamura S. 2010. Ectopic expression of wheat and barley DOG1-like genes promotes seed dormancy in Arabidopsis. Plant Sci, 179: 536-542.
2. Ashikawa I, Abe F, Nakamura S. 2013. DOG1-like genes in cereals: investigation of their function by means of ectopic expression in Arabidopsis. Plant Sci, 208: 1-9.
3. Attucci S, Carde J. P, Raymond P, Saint-Ges V, Spiteri A, Pradet A. 1991. Oxidative phosphorylation by mitochondria extracted from dry sunflower seeds. Plant Physiol, 95: 390-398.
4. Baroux C, Grossniklaus U. 2019. Seeds-An evolutionary innovation underlying reproductive success in flowering plants. İn Grossniklaus U. Editor. Current topics in developmental biology. 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States; 131, 605-642.
5. Baskin CC, Baskin JM. 1998. Seeds. Ecology, biogeography, and, evolution of dormancy and germination. San Diego: Academic Press.
6. Baskin JM, Baskin CC. 2003. Classification, biogeography, and phylogenetic relationships of seed dormancy., In: Smith RD, Dickie JB, Linnington SH, Pritchard HW, Probert RJ, Editors. Seed conservation: Turning science into practice. Kew: Royal Botanic Gardens; p. 517-544.
7. Baskin JM, Baskin CC. 2004. A classification system for seed dormancy. Seed Sci Res, 14: 1-16.
8. Baskin JM, Baskin CC. 2005. Underdeveloped embryos in dwarf seeds and implications for assignment to dormancy class. Seed Sci Res, 15: 357-360.

9. Bentsink L, Hanson J, Hanhart CJ, Blankestijn-de Vries H, Coltrane C, Keizer P, El-Lithy M, Alonso-Blanco C, de Andrés MT, Reymond M et al. 2010. Natural variation for seed dormancy in Arabidopsis is regulated by additive genetic and molecular pathways. Proc Natl Acad Sci U S A, 107: 4264–4269.
10. Bewley JD. 1997a. Seed germination and dormancy. Plant cell, 9: 1055-1066.
11. Bewley JD. 1997b. Breaking down the walls—a role for endo-β-mannanase in release from seed dormancy?. Trends Plant Sci, 2: 464-469.
12. Bewley JD, Marcus A. 1990. Gene expression in seed development and germination. In: Chon WE, Moldave K, Editors. Progress in nucleic acid research and molecular biology, Vol 38. San Diego: Academic Press, p. 165-193.
13. Boussardon C, Martin-Magniette ML, Godin B, Benamar A, Vittrant B, Citerne S, Mary-Huard T, Macherel D, Rajjou L ve Budar F. 2019. Novel cytonuclear combinations modify Arabidopsis thaliana seed physiology and vigor. Front Plant Sci, 10.32 doi: 10.3389/fpls.2019.00032.
14. Casal JJ, Sánchez RA. 1998. Phytochromes and seed germination. Seed Sci Res, 8: 317–329.
15. Cadman CSC, Toorop PE, Hilhorst HWM, Finch-Savage WE. 2006. Gene expression profiles of Arabidopsis Cvi seed during cycling through dormant and non-dormant states indicate a common underlying dormancy control mechanism. Plant J, 46: 805–822.
16. Chiang GCK, Barua D, Dittmar E, Kramer EM, de Casas RR, Donohue K. 2013. Pleiotropy in the wild: the dormancy gene DOG1 exerts cascading control on life cycles. Evol, 67: 883–893.
17. Comai L, Harada JJ. 1990. Transcriptional activities in dry seed nuclei indicate the timing of the transition from embryogeny to germination. Proc Natl Acad Sci USA, 87: 2671-2674.
18. Cosgrove DJ. 1997. Relaxation in a high-stress environment: the molecular bases of extensible cell walls and cell enlargement. Plant Cell, 9: 1031-1041.
19. Dommes J, Van de Walle C. 1990. Polysome formation and incorporation of new ribosomes into polysomes during germination of the embryonic axis of maize. Physiol Plant: 79: 289-296.
20. Donohue K. 2005. Seeds and seasons: interpreting germination timing in the field. Seed Sci Res, 15: 175–187.
21. Ehrenshaft M, Brambl R. 1990. Respiration and mitochondrial biogenesis in germinating embryos of maize. Plant Physiol, 93: 295-304.
22. Ellner S. 1985. ESS germination strategies in randomly varying environments. II. Reciprocal yield-law models. Theor Popul Biol, 28: 80-116.
23. Fenner M, Thompson K. 2005. The ecology of seeds. Cambridge: Cambridge University Press.
24. Fernández-Pascual E, Jiménez-Alfaro B, Caujapé-Castells J, Jaén-Molina R, Díaz TE. 2013. A local dormancy cline is related to the seed maturation environment, population genetic composition and climate. Ann Bot, 112: 937–945.
25. Finch‐Savage WE, Leubner‐Metzger G. 2006. Seed dormancy and the control of germination. New Phytol, 171: 501-523.
26. Finch‐Savage WE, Footitt S. 2017. Seed dormancy cycling and the regulation of dormancy mechanisms to time germination in variable field environments. J Exp Bot, 68: 843–856.
27. Forbis TA, Floyd SK, Queiroz AD 2002. The evolution of embryo size in angiosperms and other seed plants: implications for the evolution of seed dormancy. Evol, 56: 2112-2125.
28. Graeber K, Linkies A, Müller K, Wunchova A, Rott A, Leubner-Metzger G. 2010. Cross-species approaches to seed dormancy and germination: conservation and biodiversity of ABA-regulated mechanisms and the Brassicaceae DOG1 genes. Plant Mol Biol, 73: 67-87.
29. Graeber KAI, Nakabayashi K, Miatton E, Leubner‐Metzger G, Soppe WJ. 2012. Molecular mechanisms of seed dormancy. Plant Cell Envir, 35: 1769-1786.
30. Hilhorst HW 1995. A critical update on seed dormancy. I. Primary dormancy. Seed Sci Res, 5: 61-73.
31. Hilhorst HW. 1998. The regulation of secondary dormancy. The membrane hypothesis revisite. Seed Sci Res, 8: 77-90.
32. Kochánková J, Mandák B. 2009. How do population genetic parameters affect germination of the heterocarpic species Atriplex tatarica (Amaranthaceae)? Ann Bot, 103: 1303–1313.
33. Koornneef M, Bentsink L, Hilhorst H. 2002. Seed dormancy and germination. Curr Opin Plant Biol. 5: 33–36.
34. Kucera B, Cohn MA, Leubner-Metzger G. 2005. Plant hormone interactions during seed dormancy release and germination. Seed Sci Res, 15: 281-307.
35. Lane BG. 1991. Cellular desiccation and hydration: developmentally regulated proteins, and the maturation and germination of seed embryos. The FASEB Journal, 5: 2893-2901.
36. Leubner-Metzger G. 2003. Functions and regulation of β-1, 3-glucanases during seed germination, dormancy release and after-ripening. Seed Sci Res, 13: 17-34.
37. Li B, Foley ME. 1997. Genetic and molecular control of seed dormancy. Trends Plant Sci, 2: 384-389.
38. Linkies A, Graeber K, Knight C, Leubner‐Metzger G. 2010. The evolution of seeds. New Phytol, 186: 817-831.
39. Loddo D, Bozic, D, Calha IM, Dorado J, Izquierdo J, Šćepanović M, Baric K, Carlesı S, Leskovsek R, Peterson D, Vasileiadis VP, Veres A, Vrbničanin S, Masin R. 2019. Variability in seedling emergence for European and North American populations of Abutilon theophrasti. Weed Res, 59: 15-27, doi: 10.1111/wre.12343.
40. Martin AC. 1946. The comparative internal morphology of seeds. Am Midl Nat, 36: 513-660.
41. Mathews S, Sharrock RA. 1997. Phytochrome gene diversity. Plant Cell Environ, 20: 666–671.
42. Mathews S. 2006. Phytochrome-mediated development in land plants: red light sensing evolves to meet the challenges of changing light environments. Mol Ecol 15: 3483–3503.
43. McQueen-Mason SJ, Cosgrove DJ. 1995. Expansin mode of action on cell walls (analysis of wall hydrolysis, stress relaxation, and binding). Plant Physiol, 107: 87-100.
44. Morohashi Y, Bewley JD. 1980. Development of mitochondrial activities in pea cotyledons during and following germination of the axis. Plant Physiol, 66: 70-73.
45. Morohashi Y. 1986. Patterns of mitochondrial development in reserve tissues of germinated seeds: a survey. Physiol Plant, 66: 653-658.
46. Nikolaeva MG. 1999. Patterns of seed dormancy and germination as related to plant phylogeny and ecological and geographical conditions of their habitats. Russ J Plant Physiol, 46: 369-373.
47. Osborne DJ, Boubriak II. 1994. DNA and desiccation tolerance. Seed Sci Res, 4: 175-185.
48. Schopfer P, Plachy C. 1985. Control of seed germination by abscisic acid: III. Effect on embryo growth potential (minimum turgor pressure) and growth coefficient (cell wall extensibility) in Brassica napus L. Plant Physiol, 77: 676-686.
49. URL 1: https://t24.com.tr/haber/30-bin-yillik-cicek,197647 (erişim tarihi:15.02.2019).
50. Venable DL. 1989. Modeling the evolutionary ecology of seed banks. Ecol of Soil Seed Banks, 67: 60-384.
51. Vleeshouwers LM, Bouwmeester HJ, Karssen CM. 1995. Redefining seed dormancy: an attempt to integrate physiology and ecology. J Ecol, 83: 1031-1037.
52. Watkins JT, Cantliffe DJ. 1983. Mechanical resistance of the seed coat and endosperm during germination of Capsicum annuum at low temperature. Plant Physiol, 72: 146-150.
53. Welbaum GE, Muthui W, Wilson JH, Grayson RL, Fell RD. 1995. Weakening of muskmelon perisperm envelope tissue 4. J Exp Bot, 46: 391-400.
54. Willis CG, Baskin CC, Baskin JM, Auld JR, Venable DL, Cavender‐Bares J, NESCent Germination Working Group. 2014. The evolution of seed dormancy: environmental cues, evolutionary hubs, and diversification of the seed plants. New Phytol, 203: 300-309.
55. Zlatanova JS, Ivanov PV, Stoilov LM, Chimshirova KV, Stanchev BS. 1987. DNA repair precedes replicative synthesis during early germination in maize. Plant Mol Biol, 10: 139-144.