Paclobutrazol Dozlarının Kanola (Brassica napus L.) Fidelerinin Gelişimi Üzerindeki Fizyolojik ve Morfolojik Etkileri

Öz

Bu çalışmada, paclobutrazolün (PBZ) farklı dozlarının kolza tohumunun (Brassica napus L.) erken fide gelişimi üzerindeki etkilerini bazı fizyolojik ve morfolojik parametreler ölçülerek incelenmiştir. Gibberellin biyosentezini inhibe etme yeteneğiyle bilinen bir bitki büyüme düzenleyicisi olan PBZ’ün, kolza fidelerinin büyüme parametreleri, klorofil içeriği, bağıl su içeriği (RWC), yaprak alanı, sürgün ve kök özellikleri, elektrolit sızıntısı ve yaprak özütü özellikleri (pH ve elektriksel iletkenlik) üzerindeki etkisini değerlendirmek için beş farklı konsantrasyonda (0, 150, 300, 450, 900 ppm) bitkinin yaprak ve gövde yüzeylerine püskürtülerek uygulanmıştır. Sonuçlar, PBZ'nin kolza tohumu fideleri üzerinde doza bağlı farklı etkilerinin olduğunu, yüksek dozlarda yaprak alanı ve hacminde önemli azalmalara neden olduğunu göstermiştir. PBZ klorofil içeriğini önemli ölçüde değiştirmezken, RWC'de 300 ppm'de su tutulumunun iyileştiği görülmüştür. Ayrıca, 150–300 ppm PBZ dozlarının daha düşük elektrolit sızıntısı ile stabil bir membrana neden olduğu belirlendi. Daha yüksek dozlar ise yaprak kalınlaşması ve deformasyonu gibi morfolojik anormalliklere yol açtı. 300 ppm ve alt dozları uygun dozlar olsa da fide döneminde PBZ uygulamasının bitki gelişimi açısından önemli bir katkısı görülmemiştir. Ancak, sonraki büyüme dönemlerindeki uygulamaların kuraklık ve sıcaklık stresi üzerine etkileri araştırmalıdır.

Anahtar Kelimeler

• Paclobutrazol
• Kolza
• Kanola
• Brassica napus L
• Fide gelişimi
• Bitki büyüme düzenleyicisi

Physiological and Morphological Effects of Paclobutrazol Doses on Early Development of Canola (Brassica napus L.) Seedlings

Abstract

In this study, the effects of different doses of paclobutrazol (PBZ) on early seedling development of rapeseed (Brassica napus L.) were investigated by measuring some physiological and morphological parameters. PBZ, a plant growth regulator known for its ability to inhibit gibberellin biosynthesis, was applied by spraying on the leaf and stem surfaces of plants at five different concentrations (0, 150, 300, 450, 900 ppm) to evaluate the effects on growth parameters, chlorophyll content, relative water content (RWC), leaf area, shoot and root properties, electrolyte leakage and leaf extract properties (pH and electrical conductivity) of rapeseed seedlings. The results showed that PBZ had different dose-dependent effects on rapeseed seedlings, causing significant reductions in leaf area and volume at high doses. Although PBZ had no significant effect on chlorophyll content, an improvement in water retention (RWC) was observed at 300 ppm. Furthermore, PBZ doses of 150–300 ppm enhanced membrane stability, as indicated by reduced electrolyte leakage. In contrast, higher doses caused morphological abnormalities such as leaf thickening and deformation. While doses of 300 ppm and below were found to be appropriate, PBZ application during the seedling stage had minimal impact on overall plant development.However, the effects of PBZ applications during later growth stages on drought and heat stress should be further investigated.

Keywords

• Paclobutrazol
• Rapeseed
• Canola
• Brassica napus L
• Seedling development
• Plant growth regulator

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