_60_Co_辐照对三七叶片叶绿体和线粒体超微结构的影响

中国农学通报2015,31(16):127-133Chinese Agricultural Science Bulletin60Co-γ辐照对三七叶片叶绿体和线粒体超微结构的影响张兴芬1，何忠俊1，梁社往2，滕娟1（1云南农业大学资源与环境学院，昆明650201；2云南农业大学农学与生物技术学院，昆明650201）摘要：应用透射电子显微镜观察了经不同剂量60Co-γ射线辐照的三七叶片叶绿体和线粒体超微结构，研究了60Co-γ辐照对三七叶片叶绿体和线粒体超微结构的影响，旨在为三七辐照育种提供理论依据。

结果表明：（1）未受辐照情况下，三七叶片细胞形态规则，细胞内叶绿体数量多，基粒片层、基质片层多且有序，光合作用能力强；线粒体形态饱满，双层膜完整，管状内嵴清晰可见，基质浓厚。

（2）当辐照剂量为10Gy时，叶绿体和线粒体超微结构发生变化，但受影响程度较轻。

叶绿体被膜轻微破坏，内部基粒片层和基质片层结构基本不受影响，淀粉粒增大增多；多数线粒体结构完整，数量略微增加，可以看出，线粒体对60Co-γ射线辐照的耐受性比叶绿体强。

（3）随着辐照剂量的增加，叶绿体和线粒体超微结构受损伤程度随之增强。

当辐照剂量达到40Gy时，叶绿体大量解体，空泡大量出现，并连成大的空洞，结果必然影响叶绿素含量和光反应的正常进行，从而显著减弱光合作用强度；部分线粒体内部降解严重甚至已完全空泡化，线粒体数目明显减少，线粒体结构和功能遭到不可逆的严重损伤，细胞衰老严重。

上述结果表明，60Co-γ射线辐照对三七叶片叶绿体和线粒体超微结构产生不同程度的损伤，但适当的辐照可增加线粒体数量。

以上结论可以为不同目的的三七育种提供理论依据，并为选择最适辐照诱变育种剂量提供理论参考。

关键词：三七；60Co-γ辐照；叶绿体；线粒体；超微结构中图分类号：S331文献标志码：A论文编号：casb15010060Effect of60Co-γIrradiation on the Ultrastructure of Chloroplast andMitochondrion of Panax notoginseng LeavesZhang Xingfen1,He Zhongjun1,Liang Shewang2,Teng Juan1(1College of Resource and Environment,Yunnan Agricultural University,Kunming650201;2College of Agronomy and Biotechnology,Yunnan Agricultural University,Kunming650201) Abstract:The ultrastructure of60Co-γirradiation with different doses on chloroplast and mitochondrion of Panax notoginseng was observed by transmission electron microscop(TEM)and the effects of60Co-γirradiation on the ultrastructure were studied,aimed at providing theoretical basis for notoginseg irradition breeding.The results showed that:(1)without irradiation,the notoginseng leaf cells’shapes were normal and had many chloroplasts,there were many orderly grana lamellas and stroma lamellas,which led to strong photosynthesis capacity;mitochondria with complete double membrances were full of strong matrix and tubular cristae could be clearly observed;(2)when the irradiaion dose was10Gy,the ultrastructure of chloroplast and mitochondria changed,while they were affected to a lesser degree;the chloroplast membranes were damaged slightly,the structures of internal grana lamellas and stroma lamellas were not affected basically and there had基金项目：云南省社会发展科技计划项目“同位素指纹图谱在三七产地溯源中的应用研究与示范”(2010CA027)。

第一作者简介：张兴芬，女，1988年出生，山东潍坊人，在读研究生，主要从事药用植物栽培方面研究。

通信地址：650201云南省昆明市盘龙区北郊黑龙潭云南农业大学，E-mail：2860486990@。

通讯作者：何忠俊，男，1962年出生，陕西城固人，博士后，教授，主要从事药用植物栽培、同位素生态、土壤地理方面研究。

通信地址：650201云南省昆明市盘龙区北郊黑龙潭云南农业大学，E-mail：hezhongjun@。

收稿日期：2015-01-10，修回日期：2015-03-10。

中国农学通报more and bigger starch grains;the structures of most mitochondria were integrity and the number had slightly increased,which showed that the mitochondria had better tolerance to60Co-γirradiation than chloroplasts;(3) the study also indicated that the damage degree of the ultrastructure of chloroplast and mitochondria became more serious with the increase of irradiation dose.When the irradiation dose was40Gy,a large number of chloroplasts disintegrated,vacuoles appeared in great numbers and were connected into a big holes,the results inevitably affected chlorophyll content and light reaction,thereby significantly weakened the intensity of photosynthesis;internal degradations of some mitochondria were serious and some even had completely vacuolization,mitochondrial number was significantly reduced,meanwhile,the structure and function of mitochondria were severely damaged irreversibly with serious cell senescence.It might be concluded that there were different damages in the ultrastructure of chloroplast and mitochondrion of Panax notoginseng leaves by 60Co-γirradiation,but proper radiation could increase the number of mitochondria.The above conclusions could provide theoretical basis for notoginseng breeding of different purposes and theoretical reference for choosing the most appropriate irradiation dose of mutation breeding.Key words:Panax notoginseng;60Co-γirradiation;chloroplast;mitochondria;ultrastructure0引言三七(Panax notoginseng)，又名田七、山漆和金不换等，为五加科人参属的一种多年生阴生草本植物，是驰名中外的名贵中药材，主产于云南和广西，具有显著的散瘀止血、消肿定痛的功效[1-4]，广泛应用于跌打损伤、冠心病、心绞痛、脑血管后遗症、高血压等疾病的治疗中，是许多中成药的主要成分[5]。

然而，三七生态适应性差、地理分布窄、生长环境要求特殊，生长周期长（2~3年结果）、繁殖系数低、种子寿命短、连作障碍日趋严重，加上中国三七科研工作起步较晚，三七的良种选育和快速栽培成为亟待解决的问题。

近年来，学者多集中于三七的系统育种、杂交育种和组织培养体系的研究，利用辐照诱变改善三七种质、培育三七新品种仍然是研究较少的领域[6]。

叶绿体和线粒体在植物细胞能量代谢上极具重要性。

叶绿体是植物细胞进行光合作用的场所，它把光能转换成化学能贮存在有机物中，其进行的光合作用是地球上一切生命活动的初级能源。

线粒体是细胞进行呼吸和产能的主要场所，是真核细胞中糖类、脂类和蛋白质最终氧化放能的场所，是将有机物高效转换成为细胞生命活动直接能源ATP的细胞器，为植物的生长和代谢提供能量来源。

它们的形态结构、大小、数目和分布常因植物所处的不同环境条件而发生相应的变化，目前，有关二者在高温干旱[7-8]、水分[9]、盐胁迫[10]及镉[11-12]、铁[13]等微量元素影响下的研究较多，而有关60Co-γ射线辐照对植物叶片叶绿体和线粒体超微结构影响的研究报道较少[14]。