^(60)Co-γ射线辐照对桂花枝条生长和生理指标的影响及耐辐照性评价

Effect of ^(60)Co-γ Radiation on the Growth,Physiological Indexes and Radiotolerance of Osmanthus fragrans Branches

为研究不同桂花扦插枝条的辐照诱变作用及其耐辐照性,以^(60)Co-γ射线对柳叶苏桂(金桂)、波叶银桂(银桂)和满条红桂(丹桂)的扦插枝条进行辐照,辐照剂量分别为15、25、35、45 Gy,计算生根数量和新根长度,检测新生叶的可溶性糖、可溶性蛋白质含量和遗传物质DNA,并计算桂花枝条半致死剂量(LD_(50))和综合评价值D。结果表明,3个桂花品种的根形态特征、新生叶的可溶性糖和可溶性蛋白质含量与辐照剂量均呈负相关;辐照引起新生叶遗传物质DNA的改变;柳叶苏桂、波叶银桂和满条红桂的综合评价值D分别为0.696、0.636和0.011,LD_(50)分别为39.77、32.19和27.96 Gy,表明金桂耐辐照性最强,银桂其次,丹桂最弱。本研究结果为桂花辐照育种适宜剂量的选择提供了依据,也为桂花不同品种群的辐照育种奠定了基础。

To systematically study the change of growth, physiological indexes and radiotolerance of Osmanthus fragrans Branches, three species of osmanthus were subjected to （60）Co-γ radiation. Four different radiation dose （15,25,35,45 Gy） were conducted to study the influences of （60）Co-γ radiation on the morphology of radicle and spear of three O. fragrans （i. e. , O. fragrans jingui, O. fragrans yingui, O. fragrans dangui） and DNA, ascertain the medial lethal dose （LD50） , the branches without irradiation treatment were taken as control. The results showed that the number and length of roots, soluble sugar and soluble protein content in the buds of three species of O. fragrans were negatively correlated with radiation dose. LD50 dose for branches of O. fragrans jingui, O. fragrans yingui and O. fragrans dangui were 39.77,32.19, 27.96 Gy respectively, indicating the radiotoleranee of O. fragrans jingui is the highest, followed by O. fragrans yingui, and O. fragrans dangui is the lowest. This research can provide evidence for the selection of suitable radiation dose for Osmanthus fragrans mutation breeding and also provide for a basis for irradiation breeding in O. fragrans.