重金属对蚕豆种子萌发及体细胞分裂的影响

Effects of heavy metals on seed germination and somatic cell division of broad bean

采用醋酸铅胁迫处理蚕豆种子及其侧根,研究其不同浓度对蚕豆种子侧根萌发情况、侧根根系活力、侧根根尖细胞微核率、侧根形态和颜色及蚕豆幼苗叶片中叶绿素含量等的影响.结果显示,同一处理浓度下,随着醋酸铅胁迫处理时间的延长,蚕豆侧根根系活力减弱,根尖细胞微核率上升,侧根根长增加幅度和侧根发生率升高幅度减小,幼苗叶片内叶绿素含量下降,而侧根弯曲度未发生变化;同一处理时间下,醋酸铅处理浓度与侧根根系活力、幼苗叶片内叶绿素含量成反比,与侧根根尖细胞微核率成正比.另外,随着醋酸铅胁迫处理时间的延长和处理浓度的增大,蚕豆幼苗侧根的颜色发生明显变化甚至出现烂根现象.与对照相比,不同浓度的醋酸铅胁迫对蚕豆种子侧根萌发、侧根根尖细胞微核率、侧根根系活力、侧根形态和颜色及蚕豆幼苗叶片内叶绿素含量均有不同程度的影响.

Seeds and lateral roots of broad bean were treated with lead acetate stress to study the influence of different concentrations of lead acetate on lateral root germination, lateral root vigor, root tip cell micronucleus rate, lateral root mor- phology and color of broad bean seed and the chlorophyll content of broad bean seedling leaves and so on. The results showed that under the same concentration of lead acetate, with the extension of treatment time, the lateral root vigor of broad bean was reduced, the root tip cell micronucleus rate was increased, length increased range and incidence rate ascending range of lateral root were decreased, chlorophyll content in leaves was decreased, however the lateral root curvature was unchanged; Under the same treatment time, concentration of lead acetate was inversely proportional to lateral root vigor and chlorophyll content in leaves, conversely, treatment concentration of lead acetate in direct proportion to root tip cell micronucleus rate of lateral root. In addition, with extension of treatment time and increase of treatment concentration of lead acetate, the color of lateral root of broad bean seedling altered obviously and even appeared root rot. The above showed that different concentrations of lead acetate had varying effects on lateral root germination of broad bean seeds, root tip cell micronucleus rate, lat-eral root vigor, lateral root morphology and color and chlorophyll content of broad bean seedling leaves compared with the control.