盐胁迫对菊花‘紫燕翻飞’生长及生理特性的影响

Effects of Growth and Physiological Characteristics of Chrysanthemum‘Ziyanfanfei’Under Salt Stress

为探究盐胁迫对大菊生长及生理特性的影响,明确其对盐胁迫响应的生理机制,本试验以传统大菊品种‘紫燕翻飞’为材料,设置不同浓度盐(0、50、100、150、200 mmol/L NaCl)胁迫处理,研究其对‘紫燕翻飞’株高、叶长、叶宽、植株地上部和地下部干重、根冠比以及叶片丙二醛(MDA)含量、脯氨酸含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、相对电导率(REC)、叶绿素含量、相对含水量的影响。结果表明,与对照(0 mmol/L NaCl)相比,随着NaCl浓度升高,株高呈下降趋势,叶长、叶宽无显著变化,地上部干重、地下部干重整体呈下降趋势,根冠比则呈上升趋势;50 mmol/L NaCl处理下,各生长指标与对照相比无显著差异,当NaCl浓度增至100、150、200 mmol/L时,株高、地上部干重、地下部干重较对照均显著降低(100 mmol/L NaCl处理的株高除外),根冠比均显著增大。随着盐浓度升高及胁迫时间延长,菊花‘紫燕翻飞’叶片MDA含量、相对电导率及脯氨酸含量均呈逐渐上升趋势;低浓度盐(50、100 mmol/L NaCl)胁迫下,叶片SOD、POD活性呈升高趋势,高浓度盐(150、200 mmol/L NaCl)胁迫下,SOD和POD活性均呈现先升后降的变化趋势,且均显著高于对照;叶片叶绿素含量、相对含水量则均呈逐渐下降趋势。可见,盐胁迫处理下菊花‘紫燕翻飞’幼苗生长受到一定程度的抑制,植株可通过提高脯氨酸含量、增强SOD和POD活性来减缓盐胁迫对其造成的伤害,因此该品种菊花具备一定的耐盐能力。

To identify the effects of salt stress on the growth and physiological characteristics of chrysanthemum‘Ziyanfanfei’,and to explore the physiological mechanism of its response to salt stress.The chrysanthemum‘Ziyanfanfei’was used as the test material,and plants were treated with 0,50,100,150,200 mmol/L NaCl soulution.Then the plant height,leaf length,leaf width,shoot dry weight,root dry weight,root/shoot ratio,malondialdehyde(MDA)concentration,leaf relative electrical conductivity(REC),proline concentration,superoxide dismutase(SOD)and peroxidase(POD)activities,chlorophyll concentration,leaf relative water content and so on were measured.The results showed that with the increase of salt stress,the plant height tended to decrease,leaf length and leaf width had no change,the shoot dry weight and root dry weight tended to decrease,and the root-shoot ratio showed an increasing trend compared with the control(0 mmol/L NaCl).Under 50 mmol/L NaCl treatment,there were no remarkable differences in growth indexes in comparison with the control.Under 100,150,200 mmol/L NaCl treatment,the plant height,shoot dry weight and root dry weight significantly decreased compared with the control(except the plant height treated with 100 mmol/L NaCl),while root/shoot ratio increased remarkably.MDA,REC,and proline contents in the leaves of‘Ziyanfanfei’gradually increased with the rise of NaCl in concentration and the prolongation in treating time.The SOD and POD activities showed an obvious decrease under the conditions of 50 and 100 mmol/L NaCl,and the SOD and POD activities were high than those of the control group under the conditions of 150 and 200 mmol/L NaCl,and the SOD and POD activities decreased after the first increase.The chlorophyll content and leaf relative water content of leaves showed a decreasing trend.The comprehensive analysis showed that the growth of chrysanthemum‘Ziyanfanfei’was inhibited under salt stress,and the plant could reduce the damage caused by salt stress by increasing the content of proline,enhancing the activities of SOD and POD,and had a certain ability of salt tolerance.