锰对西藏不同地域野生赖草萌发的影响及评价

Effects and Evaluations on Germination Period of Wild Leymus secalinus in Different Regions of Tibet under the MnCl_2 Stress

以采自西藏4个不同地域的野生赖草种子为材料,采用发芽盒滤纸水培法,研究不同浓度锰处理(0、20、50、100、200、300、400和500 mg/L)对4个不同地域的野生赖草种子发芽参数(发芽率、发芽势、发芽指数和活力指数)及幼苗生长指标(胚芽长、胚根长、胚根伸长率、胚芽鲜重和胚根鲜重)和丙二醛(MDA)含量的影响。以期为赖草在西藏重金属污染地治理中的运用和西藏赖草种子资源的评价与利用提供科学参考依据。结果表明;低浓度锰处理时,种子发芽参数和幼苗生长指标均有所增加,使得种子萌发时间集中。当锰浓度超过一定值后,锰对种子发芽参数和幼苗生长指标均有抑制作用。不同赖草种子发芽参数和幼苗生长指标对锰胁迫的响应有所不同。锰胁迫下,赖草中MDA含量整体上随着锰浓度的增大而升高。试验表明,低浓度锰处理对赖草的萌发和幼苗生长均有促进作用,高浓度抑制其萌发和生长,但此过程中氯化锰对赖草会产生毒害作用。试验最后用隶属函数对其抗锰性进行评价,结果表明,采自达孜的赖草对锰胁迫具有较强的抗性。

In order to study the impact of different concentrations of Mn^（2＋）（0,20,50,100,200,300,400 and 500 mg/L）on germination parameters such as germination rate,germination potential,germination index and vigor index of wild Leymus secalinus seeds in different regions and its seedling growth index such as germ length,radicle length,radicle elongation,plumule fresh weight and root fresh weight and the malondialdehyde（MDA） content,wild Leymus secalinus seeds collected from 4 different regions of Tibet were taken as meterials and the box germination method was applied,for the purpose to provide scientific reference for the utilization of Leymus secalinus in the remediation of heavy metals polluted sites in Tibet as well as the evaluation of seed resource of Leymus secalinus. The results showed that both germination parameters and seeding growth index increased with low concentration of manganese,which made germination time at the same time roughly. When the manganese concentration exceeded a certain value,it can inhibit the germination parameters and seedling growth parameters. The germination parameters and seedling growth parameters of different Leymus secalinus seeds reacted to manganese stress differently. Under manganese stress,MDA content in Leymus secalinus increased with the increasing of manganese concentration as a whole. The study showed that the low concentration of manganese can promote the germination and seedling,while high concentration can inhibit them and manganese chloride will result in pernicious effect on Leymus secalinus in the process. Membership function was applied to evaluate Leymus secalinus＇ Mn-resistance and the results showed that the Leymus secalinus Dagze had stronger resistance to manganese stress.