玉米种子萌发特性对不同浓度PEG-6000的响应

Response of Maize Seed Germination Characteristics to Different Concentrations PEG-6000

【目的】分析不同浓度聚乙二醇6000(PEG-6000)对玉米萌发特性的影响,为广西抗旱玉米新品种选育提供参考依据。【方法】以玉米品种桂单162为试验材料进行PEG-6000模拟干旱胁迫,测定分析其在不同浓度[0(对照,CK)、5%、10%、15%、20%、25%和30%]PEG-6000溶液处理下的发芽势、发芽率、萌发指数、胚根长、胚芽长、幼苗全长、胚根干重、胚芽干重和贮藏物质运转率等萌发指标。【结果】随着PEG-6000浓度的提高,玉米种子的发芽势、发芽率、萌发指数、胚根长、胚芽长、幼苗全长、胚根干重、胚芽干重和贮藏物质运转率均呈逐渐下降趋势。当PEG-6000浓度为25%时,上述各指标较CK分别极显著下降77.03%、68.24%、75.52%、73.04%、83.86%、77.51%、89.67%、92.64%和91.68%(P<0.01,下同),与PEG-6000浓度为30%时的相应指标相比均无显著差异(P>0.05),但与PEG-6000浓度为20%时相比除胚芽长外均显著(P<0.05)或极显著低于其他相应的指标。相关分析结果表明,PEG-6000浓度与种子发芽势、发芽率、萌发指数、胚根长、胚芽长、幼苗全长、胚根干重、胚芽干重和贮藏物质运转率均呈极显著负相关,相关系数分别为-0.985、-0.886、-0.971、-0.975、-0.980、-0.990、-0.978、-0.978和-0.979。【结论】不同浓度PEG-6000干旱胁迫对玉米种子发芽势、发芽率、萌发指数、胚根长、胚芽长、幼苗全长、胚芽干重、胚根干重和贮藏物质转运率等具有明显的抑制作用,提高PEG-6000浓度会延缓玉米种子发芽时间,降低发芽能力,限制其胚根和胚芽的生长发育,使种子的贮藏物质运转率降低。在玉米干旱胁迫研究中建议选用的PEG-6000浓度为15%或20%。

【Objective】The effects of different concentrations of polyethylene glycol 6000(PEG-6000)on maize germination characteristics were analyzed to provide a reference basis for the breeding of drought resistant new maize varieties in Guangxi.【Method】Using maize variety Guidan 162 as experimental material,PEG-6000 simulated drought stress was carried out,analyzed maize in different concentrations of[0(control,CK),5%,10%,15%,20%,25%and 30%]PEG-6000 solution under the process of germination potential,germination rate,germination index,radicle length,plumule length,seedling length,radicle dry weight of radicle,dry weight of plumule and storage material transfer rate.【Result】With the increase of PEG-6000 concentration,the germination potential,germination rate,germination index,radicle length,plumule length,seedling length,dry weight of radicle,dry weight of plumule and storage material transfer rate of maize decreased gradually.When the concentration of PEG-6000 was 25%,the above indexes extremely significantly(P<0.01,the same as below)decreased by 77.03%,68.24%,75.52%,73.00%,83.86%,77.51%,89.67%,92.64%and 91.68%respectively compared with CK.There was no significant difference compared with the corresponding indexes when the concentration of PEG-6000 was 30%(P>0.05),but compared with the concentration of PEG-6000 was 20%,they were significantly(P<0.05)or extremely significant lower than other corresponding indexes except length of plumule.The results of correlation analysis showed that PEG-6000 concentration had extremely significant negative correlation with germination potential,germination rate,germination index,radicle length,plumule length,seedling length,dry weight of radicle,dry weight of plumule and storage material transfer rate,and the correlation coefficients were-0.985,-0.886,-0.971,-0.975,-0.980,-0.990,-0.978,-0.978 and-0.979,respectively.【Conclusion】Drought stress with different concentrations of PEG-6000 had obvious inhibitory effects on maize seed germination potential,germination rate,germination index,radicle length,plumule length,seedling length,dry weight of radicle,dry weight of plumule and storage material transfer rate.Increasing PEG-6000 concentration will delay maize seed germination time,reduce germination ability,limit the growth and development of radicle and plumule and reduce the storage material transfer rate of seeds.It was suggested that the concentration of PEG-6000 was 15%or 20%in the study of maize drought stress.