快中子辐照对蝴蝶兰离体茎段生理特性的影响

Effect of Fast Neutron Irradiation on Physiological Characteristics of the Tissue-cultured Stem Segments of Phalaenopsis

为了探究蝴蝶兰对快中子辐照注量的耐受性,利用快中子脉冲堆对蝴蝶兰Phalaenopsis Taisuco Firebird和Phalaenopsis Neyshanguniang的组培苗茎段进行辐照处理,研究了不同辐照注量对植株抗氧化酶活性、渗透调节物质和膜脂过氧化作用的影响。结果表明,茎段形成的叶片组织内过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化歧化酶(SOD)活性,随着辐照注量的增加均呈现先升高后降低的趋势。较低注量(300×10~8n·cm^(-2))辐照促进抗氧化酶活性增强,提高蝴蝶兰茎段的抗辐射能力;高注量(>2 500×10~8n·cm^(-2))辐照显著抑制抗氧化酶活性,造成蝴蝶兰茎段损伤。快中子辐照注量与可溶性蛋白质含量呈极显著负相关(r=-0.734,r=-0.669,P<0.01),低注量辐照促进可溶性蛋白质合成代谢,与丙二醛(MDA)含量呈极显著正相关(r=0.929,r=0.926,P<0.01),高注量辐照会加剧膜脂过氧化作用。Taisuco Firebird茎段比Neyshanguniang茎段更易受快中子辐照的影响。本研究结果为花卉快中子辐照诱变育种研究提供了一定的理论依据和技术参考。

To explore the tolerance of phalaenopsis to fast neutron irradiation,the shoots of the tissue culture seedlings of Phalaenopsis Taisuco Firebird and Phalaenopsis Neyshanguniang were irradiated with fast neutron pulse reactor,and the effects of different effects of irradiation fluids on antioxidant enzyme activities,osmotic adjustment substances and membrane lipid peroxidation in plants were studied. The results showed that the activities of catalase（ CAT）,peroxidase（ POD） and superoxide dismutase（ SOD） in the leaf tissue of stem segments increased first and then decreased with the increase of irradiation trend. The lower dose（ 300 × 10^8n·cm（-2）） irradiation promoted the activity of antioxidase and improved the anti-irradiation ability of Phalaenopsis. The higher dose（ 2 500 × 10^8n·cm（-2）） irradiation inhibited the activity of antioxidase resulting in phloem injury of Phalaenopsis. Soluble protein content had significant negative correlation with fast neutron irradiation dose（ r =-0. 734,r =-0. 669,p 0. 01）,while MDA content had significant positive correlation with fast neutron irradiation dose（ r = 0. 929,r = 0. 926,p 0. 01）. In other words,low-dose irradiation promoted soluble protein anabolism and high-dose irradiation would exacerbate membrane lipid peroxidation. To sum up,Taisuco Firebird stems were more vulnerable to fast neutron irradiation than Neyshanguniang.The study provides a theoretical basis and technical reference for fast neutron irradiation on mutation breeding of flowers.