Bor Elementi ve Niasinin Nantes Havuç (Daucus carota L.) Çeşidinin Büyümesi Üzerine Etkileri

Abstract

The effects of boron and niacin deficiency and excess on the growth of carrot (Daucus carota L. cv. nantes) individually and together was investigated. The seeds of plant sowed directly to lacking boron, and 6 mg/l boron (0) and 0,5 mg/l nicotinic acid (control, K), and 31 mg/l (5B) boron, and also lacking niasin (nicotinic acid)(0N), 2,5 mg/l (5N), and finally 31 mg/l boron and 2,5 mg/l niacin together (5B/5N) containing Murashige-Skoog nutrient medium. Root-shoot length and IAA hormone and pigment (chlorophyll and carotenoid) content were determined in the germinated seeds eight weeks old plantlets. According to the results, either boron or niacin lacking or excess boron or excess niacin in the medium, did not effect germination rate. On the other hand, boron deficiency caused an increase in root length and IAA content and an increase in pigment content; while the excess boron and excess niacin caused a decrease in root length and IAA content but an increase in shoot length and a decrease in pigment content, at the end of eight week. In contrary, niacin deficiency caused a decrease in root length and shoot length and pigment content, but an excess increse in IAA content. We obtained roots and shoots of carrot plant in an approximately equal length when we grew them in the medium which added excess boron (five times more) and excess niacin (five times more) together, and this medium also caused an increase with the highest value in IAA content and pigment and carotenoid content of carrot plant in comparison to the other mediums. So we can propose to be used niacin towards the toxic effects of boron.