Cytogenetical Studies on the Impact of Gamma Rays to Induce Variation in Vitro in Paulownia (Paulownia Tomentosa)

Abstract

aulownia (Paulownia tomentosa L) is the one useful trees in China. All parts of paulownia tree (leaves, flowers, wood, bark, roots and seeds) have been used for many medicinal and industrial purposes. Buds were cultured on ¾ Murashige and Skoog (MS) solid medium supplemented with 0.2 mg/l benzyl adenine and 0.1 mg/l kinetin. The survival percentage and mean shoot length of irradiated plantlets with gamma radiation doses of 10, 20, 30, 40 and 50 Gy were calculated after eight weeks. The results showed a decrease in the survival percentage and mean shoot length by increasing gamma radiation doses. The lethal dose was 50 Gy and the optimal dose for explant survival was 10 Gy. Anatomical and ultrastructure of un-irradiated and irradiated paulownia were examined based on photonic and electron microscopy for plantlets leaves after 16 days from culturing. Anatomical studied of leaf surface showed variations in epidermal cells, trichomes, stomata and mesophyll cells. The ultrastructure sections showed formation of plastoglobule and starch granules which indicates a reduced carbon metabolism at sublethal dose of 40 Gy.