地被菊‘火焰’对干旱胁迫的响应研究

Responses to Drought Stress in Ground-covering Chrysanthemum cv'Huoyan'

为探讨地被菊‘火焰’在干旱胁迫下的响应机制,采用盆栽控水法,研究不同干旱胁迫强度下地被菊‘火焰’生长、生理生化和光合生理的变化。结果表明:(1)干旱胁迫抑制‘火焰’生长发育,其中,中度和重度胁迫对植株生长影响较大。(2)随着干旱胁迫强度加剧,叶片相对含水量(LRWC)降低,叶片脯氨酸(Pro)、可溶性糖(Ss)和可溶性蛋白(Sp)含量增加,丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和叶绿素(Chl)含量升高。(3)光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)随干旱胁迫程度加大而降低,胞间CO2浓度(Ci)呈先降后升趋势。结果表明土壤含水量为(13.33±0.2)%时对‘火焰’生长影响较小;土壤含水量为(10±0.2)%时,植株生长缓慢;土壤含水量为(6.66±0.2)%时‘火焰’生长明显受到抑制。

To provide optimized cultivation procedures for ground-covering chrysanthemum,this study investigated the growth and physiological responses of the chrysanthemum plant to drought stress.Using ground-covering chrysanthemum cultivar＇Huoyan＇as material and pot-cultivation experiment with controlled irrigation,parameters of growth,stress physiology and biochemistry and photosynthetic physiology of＇Huoyan＇plants under varied degree of drought stress were measured.The results showed that：drought stress inhibited plant growth,especially under moderate and severe drought stress conditions.Under increased degree of drought stress leaf relative water content（LRWC）was decreased,proline（Pro）,contents of soluble sugar（Ss）and soluble protein（Sp）were increased,malonic aldehyde（MDA）content,the activity of superoxide dismutase（SOD）and chlorophyll content（Chl）were increased.Under drought stress,photosynthetic rate（Pn）,stomatal conductance（Gs）and transpiration rate（Tr）were significantly decreased while intercellular CO2concentration（Ci）was first increased and then decreased.When soil moisture content was 13.33%±0.2%little impact on plant growth was observed.When soil moisture dropped to 10%±0.2%,the plants grew slowly.When soil moisture reached 6.66%±0.2%plant growth was suppressed considerably.