Furocoumarin production by callus tissues of Heracleum sphondylium L

cal callo callus chemical composition composition chimique coumarine coumarins cultivo in vitro culture in vitro culture media cumarinas explant explantes explants fitotoxinas fleur flores flowers heracleum sphondylium in vitro culture inflorescence inflorescences inflorescencias medio de cultivo methoxsalen milieu de culture phytotoxine phytotoxins plant growth substances sustancias de crecimiento vegetal