^(60)Co-γ辐射对桂花幼苗生长及生理指标的影响

Effect of ^(60)Co-γ Rays Irradiation on Seedling Growth and Physiological Indexes of Osmanthus fragrans

为了研究核辐射技术在桂花诱变育种上的应用,以^(60)Co-γ射线辐照‘潢川金桂’与‘籽银桂’种子,测定不同剂量对2个桂花品种M_1代的影响,确定桂花种子的适宜诱变剂量,为开展桂花诱变育种工作奠定理论基础。结果表明:随着辐射剂量的增加,幼苗出苗率、苗高、地径、干质量显著下降;叶绿素质量分数、可溶性蛋白质量分数减少;SOD活性及POD活性都呈先升后降的趋势,在50Gy时达到峰值。^(60)Co-γ射线对‘籽银桂’的影响程度大于‘潢川金桂’,表明‘籽银桂’的辐射敏感性大。通过对桂花种子出苗率的回归分析知:低剂量率^(60)Co-γ射线辐照‘潢川金桂’的半致死剂量和临界致死剂量分别为135.94Gy和170.12Gy,‘籽银桂’半致死剂量与临界致死剂量分别为86.27Gy和114.68Gy。综合上述各指标,低剂量率条件下(2Gy/min)‘潢川金桂’的种子以135~155Gy的诱变剂量较适宜,而‘籽银桂’以80~100Gy较适宜。

Irradiation mutagenesis is an effective method to improve varieties characters and create new germplasm resources. At present, the use of radiation technology in mutagenesis study of grape seeds of fragrans is seldom . ＇ Huangehuan Jingui＇ and ＇ Zi Yingui ~ were irradiated by different doses of ^60Co-γ ray in this experiment, and the effect of irradiation on the M1 generation was studied. The re- sults showed that with the gradual enhancement of irradiation dosage, the growth of the fragrans were distinctly suppressed, the rate of seedling emergence, height, diameter, dry mass were dramatically reduced ; and the mass fraction of chlorophyll and the maximum values of soluble protein decreased at the seeding stage, the activities of superoxide dismutase （SOD） and peroxidase （POD） increased at first,and then declined, the largest value was presented at the 50 Gy irradiation. The effect of ^60Co-γ ray on ＇Zi Yingui＇ was obviously larger than that of the ＇ Huangchuan Jingui＇, the radio sensitivity emergence rate and the ^60Co-γ ray irradiation with low rate on ＇Huangehuan Jingui＇ showed that the half lethal dosage（LD50） and the critical dosage（LD40） were 135.94 Gy and 170.12 Gy respectively, while,the ＇Zi Yingui＇ were 86.27 Gy and 114.68 Gy . Based on above results,the appropriate dosage of ^60Co-γ ray for ＇Huangchuan Jingui＇ seeds was 135-155 Gy, 80-100 Gy for ＇Zi Yingui＇.