四种常见杂草根系及根边缘细胞对铝胁迫的响应  

Response to aluminum toxicity of four common weeds roots and border cells

作　　者：周楠[1] 刘鹏[1] 徐根娣[1] 汪晔[1] 孙芳华[1] 陈文荣[1] 

机构地区：[1]浙江师范大学植物学实验室,金华321004

出　　处：《生态学报》2009年第12期6512-6518,共7页Acta Ecologica Sinica

基　　金：浙江省重点科技攻关计划资助项目(2005C24011);浙江省自然科学基金资助项目(405135;303461);浙江省分析测试基金资助项目(03091)

摘　　要：以2种禾本科杂草(升马唐、稗草)和2种菊科杂草(旱莲草、野茼蒿)为实验材料,通过砂培法研究不同科属杂草根部对铝胁迫的响应。结果表明:4种杂草根边缘细胞活性均随着铝胁迫浓度和时间呈显著下降的趋势,但禾本科杂草根系边缘细胞的活性高于菊科杂草,且活性的降低幅度较小;4种杂草根相对伸长率均随铝浓度和处理时间的增加呈递减趋势,但铝对旱莲草和野茼蒿根生长的抑制程度要明显高于升马唐和稗草;根系的铝含量、游离脯氨酸含量、MDA含量和质膜透性均随铝处理浓度和处理时间的增加而增大,且在高铝浓度(1000mg·L-1)时达到最大值,但升马唐和稗草根系的铝含量、游离脯氨酸含量、MDA含量和质膜透性均显著低于旱莲草和野茼蒿,且随着铝浓度的增加,禾本科杂草根系的游离脯氨酸含量及MDA含量的变化没有达到显著水平(P>0.05)。由此说明,铝毒对杂草造成的伤害随着浓度增加和时间延长而加重;升马唐和稗草的根系通过较高的根边缘细胞活性和根相对伸长率及较低的铝含量、游离脯氨酸含量、MDA含量和质膜透性来增加其对铝的耐性;2种禾本科杂草(升马唐、稗草)的耐铝性高于2种菊科杂草(旱莲草、野茼蒿)。Four herbaceous plants,gramineae weeds （Digitaria ciliaris,Echinochloa crusgali） and composite weeds （Eclipta prostrata,Crassocephalum crepidioides） distributed in the red soils of the South China,were used to examine activity of root border cells,root relative elongation,levels of aluminum,proline,malondialdehyde （MDA）,and membrane permeability （MP） in the Al-treated roots. It was found that activity of root border cells was significantly decreased with increasing Al3＋ concentrations or treatment time in these four weeds. The decreasing magnitude was higher in composite weeds than in gramineae weeds,while the contents of aluminum,proline and MDA,and membrane permeability were increased in the roots. Further analysis showed that root growth was more markedly inhibited by Al in Eclipta prostrata and Crassocephalum crepidioides than in Digitaria ciliaris and Echinochloa crusgali under the same conditions. The contents of aluminum,proline and MDA,and membrane permeability in these four weeds roots reached a maximum at 1000 mg·L^-1 Al3＋ concentrations,while the increase in Digitaria ciliaris and Echinochloa crusgali were less than in Eclipta prostrata and Crassocephalum crepidioides. No significant increase was observed on contents of proline and MDA in gramineae weeds roots among the different exterior Al3＋ levels （P〉0.05）. These findings suggested that the damage levels of aluminum to these four weeds were enhanced with increasing Al concentrations and exposure time; However,the relatively higher activity of the root border cells,longer root relative elongation,lower levels of aluminum,proline,MDA and MP improved the tolerance to Al stress in Digitaria ciliaris and Echinochloa crusgali. Gramineae weeds（Digitaria ciliaris,Echinochloa crusgali） were more resistant to Al toxicity than composite weeds（Eclipta prostrata,Crassocephalum crepidioides）.

关 键 词：铝胁迫 杂草 根系 边缘细胞 耐性 

分 类 号：S451[农业科学—植物保护]