GA3处理对盐胁迫下5种牧草种子萌发及幼苗生长的影响

Effect of gibberellin on seed germination and seedling growth of five species of forage seeds

盐胁迫是限制种子萌发和幼苗生长的关键因子,适宜浓度的赤霉素(GA3)可有效缓解盐胁迫对种子造成的不利影响。为了解GA3对盐胁迫下牧草种子萌发和生长的缓解效应,筛选出促进盐胁迫下5种牧草种子萌发和幼苗生长的最佳GA3浓度,本研究以100 mmol·L^(-1)的NaCl溶液模拟盐胁迫,以黑麦草(Lolium perenne)、‘朝牧1号’稗谷(Echinochloa crusgalli‘Chaomu1’)、羊草(Leymus chinensis)、紫花苜蓿(Medicago sativa)、白三叶(Trifolium repens)5种牧草种子为试材,选取不同浓度GA3进行浸种处理,测定其发芽率、发芽指数、根长、苗高、鲜重等指标。结果表明:GA3浸种可有效缓解盐胁迫对5种牧草种子萌发和幼苗生长造成的抑制作用,且不同浓度间作用差异显著(P<0.05)。150 mg·L^(-1)的GA3能有效促进黑麦草、羊草、紫花苜蓿和白三叶种子的萌发和幼苗生长;100 mg·L^(-1)的GA3能有效促进‘朝牧1号’稗谷的种子萌发,50 mg·L^(-1)的GA3能显著促进其种苗的生长。本研究结果对盐胁迫逆境下的牧草种植及土壤改良具有参考价值。

Salt stress is a key factor in limiting seed germination and seedling growth.An appropriate concentration of gibberellin(GA3)can alleviate the adverse effects of salt stress on forage seeds.This study investigated the alleviating effect of GA3 on seed germination and growth and determined the best GA3 concentration to promote seed germination and seedling growth of five species of forage seeds under salt stress.Salt stress was simulated using 100 mmol·L^(-1) NaCl.The test materials were seeds of Lolium perenne,Echinochloa crusgalli‘Chaomu1’,Leymus chinensis,Medicago sativa,and Trifolium repens.Seeds were soaked in different concentrations of GA3.The germination rate,germination index,root length,seedling height,fresh weight,and other indices were measured.Soaking seeds in GA3 could effectively alleviate the inhibitory effects of salt stress on seed germination and seedling growth of the five forage species.The effects significantly differed among the different GA3 concentrations(P<0.05).The GA3 concentration of 150 mg·L^(-1) could effectively promote seed germination and seedling growth of L.perenne,L.chinensis,M.sativa,and T.repens.The GA3 concentration of 100 mg·L^(-1) effectively promoted seed germination of E.crusgalli,and 50 mg·L^(-1) GA3 significantly promoted seedling growth.The study findings will be valuable reference data for forage planting and soil reclamation under salt stress.