海藻糖浸种对盐胁迫下扬麦19生理特性的影响

Effects of soaking seeds in trehalose on physiological characteristics of wheat Yangmai-19 under salt stress

以扬麦19为材料,研究4个海藻糖溶液浓度(0、2、20、40 mmol·L^(-1))浸种对其种子萌发的影响。选择对种子萌发没有明显抑制效应的最适海藻糖溶液浓度(2 mmol·L-1),研究其对盐胁迫下(3 g·L^(-1)NaCl)扬麦19幼苗生长及生理特性的影响。结果表明,2 mmol·L^(-1)海藻糖溶液浸种处理对扬麦19种子发芽率和幼苗株高无显著影响,但对幼苗单株干质量有显著促进作用。在盐胁迫下,2 mmol·L^(-1)海藻糖浸种处理可显著提高扬麦19幼苗相对生长率、单株生物量、叶绿素相对含量和N含量,比水浸种处理分别提高200%、6.50%、15.07%和9.25%;幼苗脯氨酸积累速度明显加快,K^+含量及K^+/Na^+显著增加,Na^+含量显著下降(P<0.05)。双因素方差分析表明,影响幼苗K^+含量的程度依次为海藻糖>NaCl>海藻糖×NaCl。海藻糖浸种处理可以使扬麦19更快更早地积累脯氨酸,增强对K^+的吸收,以适应盐胁迫环境。

To investigate the effect of trehalose pretreatment with different concentrations of 0 , 2 , 20 and 40 mmol·L^-1 on seed germination,Yangmai-19,a high-yielding winter wheat cultivar,was selected as the experimental mate-rial. Furthermore,the optimal concentration of trehalose （2 mmol·L^-1 ） was screened out to study its effect on growth and physiological characteristics of Yangmai-19 under salt stress （3 g·L^-1 NaCl）. The results showed that the seed germination and plant height were not significantly affected in the pretreatment with 2 mmol·L^-1 trehalose, but the dry weight per plant was significantly increased. Under salt stress,compared with the non-treated seeds,the relative growth rate,biomass per plant,relative chlorophyll content and N content in the pretreatment of 2 mmol·L^-1 trehalose were significantly improved by 200% ,6. 5 0% ,15. 07% and 9. 2 5% ,respectively. Proline accumulation rate was found to be significantly increased in the seedlings pretreated with 2 mmol·L^-1 trehalose than the non-treated seeds,as well as the total K＋ content and K ＋ /Na＋ ratio, while N a＋ content was significantly decreased （ P 〈 0. 05）. Two-factor variance analysis showed that the factor orders of impacting K ＋ content was trehalose 〉 NaCl 〉 trehalose x NaCl. Trehalose pretreatment could improve the seedlings adaption to salt stress earlier, by increasing their proline accumulation and also increasing their K＋ absorption.