PEG-6000模拟干旱胁迫对芒果种子萌发的影响

Effects of PEG-6000 simulation drought stress on seed germination of mango (Mangiferca indica L.)

【目的】了解干旱胁迫对芒果种子的萌发及幼苗生长的影响,为进一步研究芒果萌发期抗旱性机理提供理论参考,为芒果抗旱品种选育打下基础。【方法】以三年芒和马切苏为材料,采用不同浓度的聚乙二醇(PEG-6000)[0(对照)、5%、10%、20%]模拟干旱胁迫,研究干旱处理对芒果种子萌发和幼苗生长的影响。【结果】三年芒和马切苏的种子发芽率、发芽势、发芽指数、活力指数、胚根鲜重、胚根长、胚芽鲜重和胚芽长均随PEG-6000浓度的升高呈下降趋势,萌发进程推迟,发芽时间延长。当PEG-6000浓度为20%时,2个芒果品种的种子均未能正常发芽。总体来看,2个芒果品种种子萌发及幼苗生长均受到不同程度的抑制,且随PEG-6000浓度的升高其抑制作用越明显。在相同PEG-6000浓度处理下,马切苏受抑制程度小于三年芒。发芽率、发芽势、发芽指数、胚根鲜重、胚根长、胚芽鲜重和胚芽长均与PEG-6000浓度呈极显著负相关(P<0.01,下同),各指标间呈极显著正相关。【结论】干旱胁迫会抑制芒果种子的萌发及幼苗生长,马切苏较三年芒耐旱性强。

【Objective】The purpose of the study was to understand the effects of the seed germination and seedling growth of mango under drought stress,which provided a theoretical reference for further study on drought tolerance mechanism of mango during germination,and laid a foundation for breeding drought tolerant varieties of mango.【Method】Effects of drought stress on the seed germination and seedling growth of Sannianmang and Machisu varieties were studied under polyethylene glylol 6000 PEG-6000 simulation drought stress with various concentrations:0(control),5%,10% and 20%.【Result】With the concentration of PEG-6000 solution increased,the germination rate,germination energy,germination index,vitality index,radicle fresh weight,radical length,germ fresh weight and germ length of Sannianmang and Machisu showed a decrease trend,the germination process postponed,and the germination duration prolonged.In addition,both mango varieties failed to germinate under 20% PEG-6000 treatment.Conclusively,the seed germination and seedling growth of the two mango varieties were restrained to varying degrees under PEG-6000 stress,and the inhibitory effect was more obvious with the increasing of PEG-6000 concentration.Under the same PEG-6000 concentration,the extent of inhibition of Machisu was less than Sannianmang.Germination rate,germination energy,germination index,radicle fresh weight,radicle length,germ fresh weight and germ length were extremely negatively related with PEG-6000 concentration(P<0.01,the same below),and extremely significant positive correlation between all the indicators was observed.【Conclusion】The seed germination and seedling growth of mango are inhibited under drought stress.Machisu have a better drought resistance than Sannianmang.