盐碱、温度及其互作对丹参种子萌发及幼苗生长的影响

Effects of salinity,alkalinity,temperature,and their interactions on seed germination and seedling growth of Salvia miltiorrhiza

丹参(Salvia miltiorrhiza)是我国传统药用植物,本研究以丹参种子为试验材料,研究了两种变温(18℃/28℃和28℃/38℃)条件下,4种浓度(6.25、12.5、25、50 mmol·L^(−1))盐溶液和4种浓度(3.125、6.25、12.5、25 mmol·L^(−1))碱溶液对丹参种子萌发及幼苗生长的影响。结果表明:盐碱、温度及其互作对丹参种子萌发及幼苗生长均有显著影响(P<0.05)。18℃/28℃处理下的丹参种子萌发和幼苗生长状况均显著优于28℃/38℃处理(P<0.05)。在18℃/28℃条件下,6.25 mmol·L^(−1)盐溶液对丹参种子萌发有促进作用,其发芽率和发芽指数显著高于清水对照(P<0.05),相对盐害率显著低于清水对照(P<0.05),12.5 mmol·L^(−1)盐溶液和3.125 mmol·L^(−1)碱溶液对丹参种子发芽率、发芽指数和相对盐害率无显著影响(P>0.05),25和50 mmol·L^(−1)盐溶液以及6.25、12.5和25 mmol·L^(−1)碱溶液胁迫处理均显著降低丹参种子发芽率和发芽指数(P<0.05),增加相对盐害率(P<0.05);28℃/38℃条件下,6.25和12.5 mmol·L^(−1)盐溶液以及3.125和6.25 mmol·L^(−1)碱溶液胁迫对丹参种子发芽率、发芽势和相对盐害率无显著影响(P>0.05),25、50 mmol·L^(−1)盐溶液和12.5、25.0 mmol·L^(−1)碱溶液均显著降低丹参种子发芽率和发芽指数(P<0.05),增加相对盐害率(P<0.05)。盐胁迫和碱胁迫处理均显著抑制丹参苗长生长(P<0.05);两种变温条件下,6.25、12.5 mmol·L^(−1)盐溶液和3.125 mmol·L^(−1)碱溶液对丹参幼苗叶长生长无显著影响(P>0.05),25、50 mmol·L^(−1)盐溶液以及6.25、12.5和25 mmol·L^(−1)碱溶液均显著抑制叶长生长(P<0.05);18℃/28℃下6.25 mmol·L^(−1)盐溶液对幼苗叶宽生长有促进作用,除28℃/38℃下6.25 mmol·L^(−1)盐溶液和3.125 mmol·L^(−1)碱溶液对叶宽生长无显著影响(P>0.05)外,其余盐碱胁迫处理均显著抑制叶宽生长(P<0.05)。综上,盐碱、温度及其交互作用显著影响丹参种子萌发和幼苗生长,低温条件下盐碱对丹参种子的影响相对较小;丹参种子萌发和幼苗生长对碱胁迫更为敏感;建议丹参种子盐碱育苗时应选择盐碱度较低的土地,适宜在18℃/28℃较低温度时进行育苗。

Salviae miltiorrhizae is a traditional Chinese medicinal plant.The effects of four concentrations(6.25,12.5,25,and 50 mmol·L^(−1))of salt solution and four concentrations(3.125,6.25,12.5,and 25 mmol·L^(−1))of alkali solution on seed germination and seedling growth of S.miltiorrhiza seeds were studied under two varying temperatures(18℃/28℃and 28℃/38℃).Salinity,alkalinity,temperature,and their interactions had significant effects on the seed germination and seedling growth of S.miltiorrhiza(P<0.05).Seed germination and seedling growth were significantly higher under 18℃/28℃than 28℃/38℃(P<0.05).Under 18℃/28℃and 6.25 mmol·L^(−1) salt solution,germination of S.miltiorrhiza was stimulated,with a significantly higher germination percentage and germination index than under water control(P<0.05).Additionally,the relative salt damage rate was significantly lower than under water control(P<0.05).There was no significant effect of 12.5 mmol·L^(−1) salt solution and 3.125 mmol·L^(−1) alkali solution on S.miltiorrhiza seed germination rate,germination index,and relative salt damage rate(P>0.05).The germination rate and germination index of S.miltiorrhiza were decreased significantly under salt solution at 25 and 50 mmol·L^(−1)and alkali solution at 6.25,12.5 and 25 mmol·L^(−1)(P<0.05),and the salt damage rate increased.Under 28℃/38℃,salt solution at 6.25 and 12.5 mmol·L^(−1) and alkali solution at 3.125 and 6.25 mmol·L^(−1) had no significant influence on the germination rate,germination potential,and relative salt damage rate of S.miltiorrhiza(P>0.05).Salt solution at 25 and 50 mmol·L^(−1) as well as alkali solution at 12.5 and 25 mmol·L^(−1) significantly reduced the germination rate and germination index of S.miltiorrhiza(P<0.05)and increased the relative salt damage rate.Salt and alkali stress inhibited root growth of S.miltiorrhiza seedlings significantly(P<0.05).Under the two different temperature conditions,salt solution at 6.25 and 12.5 mmol·L^(−1) and alkali solution at 3.125 mmol·L^(−1) had no significant effect on leaf length growth of S.miltiorrhiza seedlings(P>0.05),whereas 25 and 50 mmol·L^(−1) salt solution and 6.25,12.5 and 25 mmol·L^(−1) alkali solution stress significantly inhibited leaf length growth(P<0.05).Salt solution at 6.25 mmol·L^(−1) under 18℃/28℃promoted leaf width growth of seedlings,whereas salt solution at 6.25 mmol·L^(−1) and alkali solution at 3.125 mmol·L^(−1) under 28℃/38℃had no significant effect on leaf width growth(P>0.05).High salt and alkali stress significantly inhibited leaf width growth(P<0.05).In conclusion,salinity,alkalinity,temperature,and their interactions had a significant effect on seed germination and seedling growth of S.miltiorrhiza.Salinity and alkalinity had relatively little impact on S.miltiorrhiza seeds under low temperature.Seed germination and seedling growth of S.miltiorrhiza were more sensitive to alkali stress.It is suggested that saline-alkali breeding of S.miltiorrhiza seeds should be carried out on land with low salinity and alkalinity and at a temperature of 18℃/28℃.