Abstract:

【Objective】 To explore the influence of ⁶⁰Co-γ radiation on the mortality rate, antioxidant enzyme activity and other related physical and chemical indexes of annual cuttings of different fig varieties, and determine the best mutagenic dosage.This study has provided a scientific theoretical basis for the future use of ⁶⁰Co-γ radiation mutagenesis to improve the genetic diversity of fig, create new germplasm and cultivate new excellent varieties.【Methods】 The annual dormant branches of Brunswick and Zhonghuaziguo were used as test materials, and ⁶⁰Co-γ radiation as the irradiation source, different dosages(0, 30, 45, 60, 75 Gy)for radiation treatment were set to observe the changes in the death rate and enzyme activity of branches and leaves caused by irradiation.【Results】 With the increase of radiation dosage, the survival rate of cutting seedlings of the two varieties showed a downward trend, and the indexes of plant height, stem diameter, internode length, leaf length, leaf width and branch number showed a downward trend, while the difference of leaf length-width ratio was not significant. The activities of SOD, POD, CAT and other enzymes of Zhonghuaziguo varieties showed a trend of increasing first and then decreasing, reaching the peak at the dosage of 45 and 60 Gy, respectively, MDA content showed a trend of increasing all the time, and H₂O₂ content showed a trend of increasing first and then decreasing. The activities of SOD, POD and CAT enzymes of Brunswick varieties decreased first and then increased with the increase of radiation dose. The content of MDA and H₂O₂ basically kept rising. 【Conclusion】 Radiation leads to slow growth of fig cutting seedlings, dwarf plant height, coarse and thin stem and leaves, smaller leaves and fewer branches. It is preliminarily determined that the appropriate half lethal dose of Zhonghuaziguo is 56 Gy, and that of Brunswick is 70 Gy. The radiation tolerance of Brunswick is higher than that of Zhonghuaziguo.

Key words: ⁶⁰Co-γ radiation; fig; irradiation effect; enzyme activity

摘要：

【目的】研究⁶⁰Co-γ射线对不同无花果品种一年生枝条死亡率、抗氧化酶活性等相关理化指标的影响,确定最佳辐射诱变剂量,为利用⁶⁰Co-γ射线辐射诱变技术提高无花果遗传多样性、创造新种质、培育优良新品种提供科学依据。【方法】以无花果品种布兰瑞克和中华紫果一年生休眠枝为试材,采用⁶⁰Co-γ射线为辐照源,设置不同剂量0、30、45、60、75 Gy的辐射处理,分析辐照引起枝叶死亡率、酶活性等变化。【结果】随着辐射剂量的增加,2个无花果品种扦插苗成活率呈下降趋势,株高、茎粗、节间长度、叶片长度、叶片宽度和分枝数指标呈下降趋势,叶片长宽比差异不显著。中华紫果品种的SOD、POD、CAT等酶活性均呈现先增后减的趋势,分别在45、60 Gy剂量时达到峰值,MDA含量呈现一直上升趋势,H₂O₂含量呈现先增后降趋势。布兰瑞克品种的SOD、POD、CAT酶活性,随着辐射剂量的增加均呈现先降后增趋势。MDA、H₂O₂含量基本保持上升趋势。【结论】辐射导致无花果扦插苗幼苗生长缓慢、株高矮化、茎粗变细、叶片变小、分枝减少。中华紫果的半致死辐射剂量为56 Gy,布兰瑞克为70 Gy,布兰瑞克对辐射的耐受性高于中华紫果。

关键词: ⁶⁰Co-γ射线, 无花果, 辐射效应, 酶活性