盐碱及变温条件对花苜蓿种子发芽的影响

用3个变温处理(10/20℃,15/25℃,20/30℃)、6个浓度盐处理(盐为NaCl,浓度为0、50mmol/L、100mmol/L、150mmol/L、200mmol/L、250mmol/L)和碱处理(碱为Na2CO3,浓度为0、5mmol/L、10mmol/L、15mmol/L、20mmol/L、25mmol/L)研究盐、碱以及盐碱与温度的交互作用对两种不同来源花苜蓿种子萌发的影响。结果表明:随着盐、碱浓度的升高,种子发芽率、发芽速度均显著降低。低浓度盐、碱条件下,温度对花苜蓿种子发芽影响不显著;但在较高浓度的盐、碱条件下,不同温度处理对种子发芽率和发芽速度的影响差异显著;最适发芽温度为15/25℃。随着盐浓度升高,花苜蓿种子胚根长度逐渐减小,但胚轴长度没有明显变化;在一定浓度Na2CO3胁迫下花苜蓿能正常发芽,当Na2CO3浓度为15mmol/L(pH=10.95)时,两种花苜蓿发芽率均高于60%。两种花苜蓿相比较,林下花苜蓿抗盐碱性高于草甸花苜蓿。

Effect of Salinity,Alkalinity and Temperature on Germination of Medicago ruthenica Seeds

The effects of salinity, alkalinity and temperature on germination of two accessions of Medicago ruthenica under different treatments of temperature (10/20℃,15/25℃,20/30℃), NaCl (0, 50mmol/L, 100mmol/L, 150mmol/L, 200mmol/L, 250mmol/L) and Na_2CO_3 (0,5mmol/L,10mmol/L,15mmol/L,20mmol/L,25mmol/L) were studied. The results showed that the germination percentage and the germination rate were not significantly affected by low salt concentrations and their interactions with temperature, but at higher level of salt concentrations, there were significant effects on germination percentage and the germination rate. The optimum temperature for seed germination was 15/25℃. Radicles of M. ruthenica were significantly affected by low salt concentrations, but not for hypocotyl. M. ruthenica germinated well in some Na_2CO_3 concentrations lower than 20mmol/L, germination percentage of two accessions of M. ruthenica were higher than 60% at 15mmol/L Na2CO3 (pH=10.95). The tolerance of Linxia was higher than Caodian.