Effect of Some Heavy Metals on Seed Germination and Seedling Growth in Fodder Turnip (Brassica rapa L. var. rapa)

Abstract

In this study, effect of some heavy metals (Pb, Cu, Cd ve Mn) in the form of nitrate salt at different

concentrations (0.5, 1, 3, 5 ve 7.0 mM) on seed germination and root-shoot growth in Brassica rapa L. var. rapa

(fodder turnip) were investigated. After surface sterilization, the seeds were allowed to inflate in 5 ml solutions at

the determined concentrations of heavy metals, while the control group was inflated in distilled water for 6 hours.

At the end of this period, the seeds taken from the swelling medium were sown on the double layer rough filter

papers, which were soaked in 5 ml of swelling medium liquid in 9 cm plastic petri-dishes, with 25 seeds on each

dishes. Immediately after sowing, the petri-dishes were covered and kept into plant growth cabinet to germinate in

the dark at 23 ± 1 ºC for 72h. The germination rates of seeds were determined at the end of 72 hours on the basis of

radicula formation. At the end of the period, root and shoot lengths of the germinated seeds in each group were also

measured and recorded. It has been determined that seed germination and root-shoot growth decrease in parallel with

the increase in applied heavy metal concentrations. Detection of the highest germination percentage of fodder turnip

(known as Pb-tolerant) in Pb treatment after Mn proves that the toxicity threshold value of this species is high.

Keywords

• Heavy metal,Brassica rapa L. var. rapa,germination,root-shoot growth

Bazı Ağır Metallerin Yem Şalgamı’nda (Brassica rapa L. var. rapa) Tohum Çimlenmesi ve Fide Büyümesi Üzerine Etkisi

Abstract

Bu çalışmada, Brassicaceae familyasına ait olan yem şalgamının (Brassica rapa L. var. rapa) tohumlarına

farklı konsantrasyonlarda (0.5, 1, 3, 5 ve 7.0 mM) nitrat tuzu şeklinde uygulanan bazı ağır metallerin (Pb, Cu, Cd

ve Mn) tohum çimlenmesi ve kök-gövde gelişimi üzerindeki etkileri incelenmiştir. Tohumlar yüzey sterilizasyonu

sonrası, ağır metallerin belirlenen konsantrasyonlardaki 5 ml’lik çözeltilerinde, kontrol grubu ise distile su içerisinde

6 saat şişirilmeye bırakılmıştır. Bu süre sonunda şişme ortamından alınan tohumlardan, 9 cm’lik plastik petriler

içerisindeki 5 ml şişme ortamı sıvısıyla ıslatılmış çift katlı kaba filtre kağıtlarının üzerine, her bir petriye 25’er

tohum gelecek şekilde ekim yapılmıştır. Ekimden hemen sonra kapağı kapatılan petriler bitki büyüme kabinine

kaldırılmış ve 72 sa süreyle 23±1 ºC’de karanlık ortamda çimlenmeye bırakılmıştır. Radikula belirimi esasına göre

tohumların çimlenme oranları 72 saat sonunda tespit edilmiştir. Ayrıca süre sonunda her bir gruptaki tohumların kök

ve gövde uzunlukları da ölçülerek kaydedilmiştir. Tohum çimlenmesi ile kök ve gövde büyümesinin, uygulanan

ağır metal konsantrasyonlarındaki artışa paralel olarak azaldığı belirlenmiştir. Pb’ye toleranslı olduğu bilinen yem

şalgamının tohumlarında Mn’dan sonra en yüksek çimlenme yüzdesinin Pb uygulamasında görülmesi, bu türün

toksisite eşik değerinin yüksek olduğunu kanıtlamaktadır.

Keywords

• Ağır metal,Brassica rapa L. var. rapa,çimlenme,kök-gövde gelişimi

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