Influence of Calcium Content of Tissue on Hyperhydricity and Shoot-Tip Necrosis of in vitro Regenerated Shoots of Lavandula angustifolia Mill

In the present study, the effects of two CaCl2 center dot 2H(2)O levels (440 and 1320 mg L-1) and two subcultures were evaluated on in vitro shoots of Lavandula angustifolia cv. Provence Blue. Ca2+ content of the apical, middle and basal portion of shoots was determined. Increasing CaCl2 center dot 2H(2)O level in the culture medium increased tissue Ca2+ content and decreased hyperhydricity. Shoot-tip necrosis also decreased with 1320 mg L-1 CaCl2 center dot 2H(2)O, but it did not occur in the second subculture. The middle and basal portion had higher Ca2+ content than apical portion. In nonhyperhydric tissues, there were smaller and more juxtaposed cells. Scanning electron microscopy of the leaves demonstrated that trichomes from in vitro leaf surface occurred in smaller quantities.