tailieunhanh - Effects of water stress on germination in six provenances of pinus brutia seeds from different bioclimatic zones in Turkey

The effects of water potential on germination were studied in six provenances of Pinus brutia from different bioclimatic zones in Turkey. Water potentials between 0 and –8 bars were obtained using polyethylene glycol 6000 (PEG-6000) solutions. | Turk J Agric For 27 (2003) 91-97 © TÜB‹TAK Effects of Water Stress on Germination in Six Provenances of Pinus brutia Seeds from Different Bioclimatic Zones in Turkey Melih BOYDAK, Hüseyin D‹R‹K, Fahrettin T‹LK‹, Mehmet ÇALIKO⁄LU ‹stanbul University, Faculty of Forestry, Department of Silviculture, 80895, Bahçeköy, ‹stanbul - TURKEY Received: Abstract: The effects of water potential on germination were studied in six provenances of Pinus brutia from different bioclimatic zones in Turkey. Water potentials between 0 and –8 bars were obtained using polyethylene glycol 6000 (PEG-6000) solutions. Seeds were kept for 28 d in light (12 h photoperiod at 1000 lux) and at 20 ± °C. A decrease in water potential produced a marked reduction in germination percentage, germination speed and germination value. Significant variations between the provenances were found. The provenances of humid regions were the most susceptible to high moisture stress, and their germination value and germination percentage showed significant reductions at –6 bars. These differences in germination ability of provenances might be attributed to intraspecific variations resulting from the effects of natural selection. Key Words: Pinus brutia, germination, polyethylene glycol, water potential Türkiye’nin Farkl› Biyoklimatik Zonlar›ndan Alt› K›z›lçam (Pinus brutia) Orijinine Ait Tohumlar›n Çimlenmesi Üzerine Su Stresinin Etkileri Özet: Bu çal›flmada, Türkiye’nin farkl› biyo-iklim bölgelerine ait alt› Pinus brutia orijininin çimlenmesi üzerine ozmotik stresin etkisi belirlenmeye çal›fl›lm›flt›r. PEG-6000 eriyi¤i kullan›larak 0 ile -8 bar aras›nda stres düzeyleri oluflturulmufltur. Tohumlar›n çimlendirilmesi 20 ± °C s›cakl›kta 12 saat ›fl›k (1000 lüks) alt›nda 28 gün esas al›narak yap›lm›flt›r. Ozmotik potansiyelin azalmas› ile çimlenme yüzdesi, çimlenme h›z› ve çimlenme de¤eri bütün orijinlerde önemli oranda azalmakla birlikte orijinlerin tutumu aras›nda önemli farkl›l›klar .