Efeect of Boron on Mitotic Index and Seed Germination of Sunflower

This work establishes the role of boron in cell division and in germination of seeds as well as the rate of growth in seedling. For this seeds of sunflower (Helianthus annus L. var. sungold) were germinated in distilled water and in nutrient solution containing varied concentrations of boron. The effect of boron on the mitotic index and mitotic phase frequencies in sunflower root meristematic cells were investigated after 48 hours of soaking in solutions. The maximum frequency of all phases as well as highest mitotic index was found to be at 0.33 mM boron treatment. Treatment of 33 mM boron was found to be toxic and had inhibitory effect on cell division. Germination percentage as well as length of radical and plumules were highest at 0.33 mM boron.