镉胁迫对青菜幼苗某些生理特性以及基因组多态性的影响  

Effects of cadmium stresses on physiological characteristics and genomic DNA polymorphism of Brassica chinensis L. seedlings

作　　者：张云芳[1] 陈楚[1] 陈晨[1] 束良佐[1] 

机构地区：[1]淮北师范大学生命科学学院,安徽省资源植物生物学重点实验室,安徽淮北235000

出　　处：《农业环境科学学报》2016年第3期432-439,共8页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(31572202);安徽省高校省级自然科学研究项目(KJ2011Z335);淮北师范大学青年科研项目(700569);安徽省省级大学生创新创业训练计划项目(201410373051)

摘　　要：以青菜品种"苏州青"为试材,采用生理生化方法和随机扩增多态性DNA(RAPD)技术,研究了镉(Cd)胁迫对青菜幼苗相关生理特性以及基因组多态性的影响。结果表明:不同浓度(1、5、10、20、40 mg·L-1)的Cd处理20 d后,青菜幼苗的鲜重、根伸长受到显著抑制,叶片的叶绿素以及蛋白质含量下降,丙二醛含量和细胞膜透性增加。选用8条寡核苷酸引物(10 bp)对青菜幼苗基因组DNA进行RAPD扩增,对照组的RAPD图谱中可分辨出55条谱带,Cd胁迫后的RAPD图谱发生改变,呈现谱带的增加、缺失和荧光强度的改变,并且与Cd浓度剂量-效应相关。随着Cd浓度的增加,幼苗叶片基因组的模板稳定性逐步下降,并且RAPD多态性与青菜幼苗的生理指标具有显著的相关性。以上结果表明,利用RAPD技术获得的DNA多态性变化谱带可作为检测Cd对青菜毒性效应的生物标记物。Cadmium（Cd）is a toxic trace pollutant that can easily be taken up by vegetable crops. The effects of Cd stresses on some physiological characteristics and genomic DNA polymorphism in Brassica chinensis cultivar ＂Suzhouqing＂ seedlings were studied by random amplified polymorphic DNA（RAPD）technique and physiological tests. Results showed that treating plants with 1, 5, 10, 20 and 40 mg·L^-1Cd for 20 days inhibited fresh weight and root elongation of seedlings, decreased chlorophyll content and total soluble protein content, but in-creased malondialdehyde content and electrolyte leakage. Using 8 oligonucleotide primers（10 bp） to amplify the genomic DNA of the seedlings by polymerase chain reaction, 55 clear RAPD bands were detected in normal seedlings. Compared with the control, the RAPD profiles of Cd-exposed seedlings showed new bands, lost normal bands, altered band intensities. In addition, DNA polymorphism was dosedependent. The genomic DNA template stability decreased with increasing Cd concentrations, and the genomic DNA polymorphism of Brassica chinensis was positively correlated with some physiological characteristics under Cd stresses. In conclusion, the DNA polymorphisms detected by RAPD technique could be used as a biomarker for detecting the genotoxic effects of Cd on Brassica chinensis.

关 键 词：青菜 镉胁迫 生理特性 RAPD DNA多态性 

分 类 号：X503.231[环境科学与工程—环境工程]