Seeds pre-treated with plant growth regulators were used to test their effects on the alleviation of juglone stress. It was observed that seed germination in tomato and wheat was inhibited by juglone and that the plant growth regulators alleviated it significantly. | Research Article Turk J Bot 34 (2010) 67-72 © TÜBİTAK doi: The effects of gibberellic acid and kinetin on overcoming the effects of juglone stress on seed germination and seedling growth İrfan TERZİ1,*, İsmail KOCAÇALIŞKAN2 1 Department of Biology, Faculty of Education, Dumlupınar University, Kütahya - TURKEY 2Department of Biology, Faculty of Science and Arts, Dumlupınar University, Kütahya - TURKEY Received: Accepted: Abstract: Juglone (5-hydroxy-1,4-naphthoquinone) is an allelochemical responsible for walnut allelopathy. The effects of gibberellic acid (GA3) and kinetin (KIN) on overcoming the effects of juglone stress on seed germination and seedling growth were investigated in barley, wheat, cucumber, alfalfa, and tomato. Seeds pre-treated with plant growth regulators were used to test their effects on the alleviation of juglone stress. It was observed that seed germination in tomato and wheat was inhibited by juglone and that the plant growth regulators alleviated it significantly. Elongation and dry weight of the seedlings of all the species used in the study were reduced significantly by juglone, and the plant growth regulators alleviated them. The most effective treatment was the GA3+KIN combination, which was best on seedling growth in tomato and wheat. Key words: Juglone stress, alleviation, gibberellic acid, kinetin, seed germination, seedling growth Tohum çimlenmesi ve fide büyümesi üzerindeki juglon stresi etkisinin yenilmesinde giberellik asit ve kinetin etkisi Özet: Juglon (5-hidroksi–1,4-naftokinon) ceviz allelopatisinden sorumlu bir allelokimyasaldır. Giberellik asit (GA3) ve kinetin (KIN)’in tohum çimlenmesi ve fide büyümesi üzerindeki juglon stresi etkisinin yenilmesindeki etkinlikleri arpa, buğday, hıyar, yonca ve domateste araştırıldı. Bitki büyüme düzenleyicileri ile ön muamele gören tohumlar juglon stresi sonrasında, etkisini büyüme düzenleyicilerinin ne kadar hafiflettiklerini test etmek için .
