外源钙调节对蓖麻种子萌发吸水和萌发的影响

目的]为了提高盐碱地种植蓖麻出苗率和成苗率。方法]通过设置不同盐分和外源钙浓度的培养液,研究了盐分胁迫下蓖麻种子的吸水过程和外源钙的调节效应。结果]对照蓖麻种子吸水率达到20.7%时吸水趋于稳定,需耗时36 h,吸水24 h后即萌发。在50 mmol/L盐分条件下,未经外源钙处理的蓖麻种子吸水趋于稳定时的吸水率比对照显著增加,各处理都在36 h吸水速率趋于稳定;培养液中加入Ca(NO3)2没有增加吸水趋于稳定时的最大吸水率,但可以缓解盐分胁迫对种子萌发速度造成的抑制作用,提早种子的萌发。在100 mmol/L盐分条件下,未经外源钙处理的蓖麻种子吸水趋于稳定时的吸水率降低;除100 mmol/L NaCl、15 mmol/L Ca(NO3)2处理在培养60 h时吸水速率趋于稳定外,其余各处理都在36 h吸水速率趋于稳定;加入外源钙离子后,蓖麻种子吸水趋于稳定时的最大吸水率没有增加,随着外源钙浓度的增加,种子萌发时间推迟。钙离子在盐分条件下使得蓖麻种子在吸水较少的情况下提前萌发。结论]外源钙对蓖麻种子的吸水和萌发具有一定的影响,但因盐分浓度而异。

Water Uptake and Germination of Castor Seeds as Influenced by Salinity and Foreign Calcium Amendment

Objective]The research aimed to improve emergence rate and seedling rate of castro bean.Method] An experiment was done in water solutions to investigate the effects of different levels of salinity(50 and 100 mmol/L and foreign calcium amendment(0,5,10,and 15 mmol/L) on seed water uptake and germination.Result] The water uptake of castor bean in the control became stable at an uptake percentage of 20.7% after 36 h of the beginning of treatment.Seed germination was observed at 24 h after the beginning of treatment.At the salinity level of 50 mmol/L,the water uptake rates became stable at 36 h after the beginning of treatment.The percentage of water uptake of non-calcium treatment was significantly higher than that of the control.The amendment of foreign calcium didn't increase the uptake percentage,but lessened the negative effects of saline stress on seed germination and made seed germinate at an early time.At the salinity level of 100 mmol/L,the percentage of water uptake of the non-calcium treatment was significantly lower than that of the control.The rate of water uptake of 15 mmol/L calcium became stable at 60 h after the beginning of treatment,and the rates of water uptake of other treatments became stable at 36 h after the beginning of treatment.The foreign calcium amendment didn't increase the percentage of water uptake.With the increase of calcium concentration,seed germination was postponed.Under saline conditions,seed germination was promoted due to the lower percentage of water uptake caused by amendment of foreign calcium promoted.Conclusion] Foreign calcium may play different roles in regulating water uptake and germination of castor seeds cultured in solutions at different salinity levels.