五氨基乙酰丙酸对逆境下草地早熟禾萌发及生长的影响

通过发芽试验,探讨不同浓度五氨基乙酰丙酸(5-ALA)对Cd胁迫、盐胁迫及干旱胁迫下草地早熟禾(Poa pratensis)种子萌发及幼苗生长的影响。本试验以草地早熟禾‘午夜’(Poa pratensis‘Midnight’)品种为材料,在Cd(2mg·L~(-1)),NaCl(50 mmol·L~(-1)),PEG(15%)3种处理下分别施加不同浓度的5-ALA(0,5,25,50,100mg·L~(-1)),分析了不同处理下种子发芽势、发芽率、可溶性蛋白等指标。结果表明:不同胁迫下较低浓度(5,25mg·L~(-1))5-ALA均能提高种子的发芽势、发芽率、芽长、根长等指标,而较高浓度(50,100mg·L~(-1))的5-ALA起抑制作用。综合比较4种不同浓度的5-ALA发现,25mg·L~(-1)对胁迫的缓解效应最优,其Cd胁迫下发芽势、发芽率分别比对照增加了21%,33.67%;NaCl胁迫下发芽势、发芽率分别增加了22.67%,23.67%;PEG模拟干旱胁迫下发芽势、发芽率分别增加了15.33%,10.67%。25mg·L~(-1) 5-ALA对NaCl,PEG胁迫下可溶性蛋白含量提高显著,分别提高了6.5和3.8μg·g-1,对于Cd胁迫,可溶性蛋白含量虽有提升但不显著。

Effects of 5-ALA on Seed Germination and Growth of Poa pratensis under Abiotic Stress

This trial was aimed to investigate the effects of different concentrations of 5-aminolevulinic acid (5-ALA) on seed germination and seedling growth of Poa pratensis under Cd stress,salt stress and drought stress with germination test.Poa pratensis 'Midnight' was used as the plant material,and five different concentrations of 5-ALA (0,5,25,50,100 mg · L-1) were applied to the treatment of Cd (2 mg · L-1),NaC1 (50 mmol · L-1) and PEG (15％).Germination energy,germination rate,soluble protein and other indexes were analyzed.The results showed that the germination energy,germination rates,bud length and root length increased with the lower concentrations (5,25 mg · L-1) of 5-ALA,and they were inhibited at the higher concentrations (5,100 mg · L-1).The best concentration was 25 mg · L-1 after a general comparison among five concentrations of 5-ALA.Under this concentration,germination energy and germination rates were increased by 21％ and 33.67％ respectively compared with the control under Cd stress.Under salt stress,germination energy and germination rates were increased by 22.67％ and 23.67％ respectively,and the two indexes were increased by 15.33％ and 10.67％ respectively under drought stress.In addition,soluble protein content was significantly increased by 6.5 μg · g-1,3.8μg ·g-1when the seedling was under salt or drought stress.As for Cd stress,soluble protein content was improved,but the influence was not significant.