逆境条件下镉对臭牡丹幼苗生理变化的影响

Effect of cadmium on the physiological changes of Clerodendrum bungei Steud.

为探究镉胁迫对臭牡丹幼苗生理变化的影响,进行土培试验,设0、0.1、0.3、0.6、0.9 mmol/L 5种镉胁迫浓度处理,测定其对臭牡丹叶片叶绿素荧光参数、丙二醛、脯氨酸、可溶性糖、可溶性蛋白含量的影响。结果表明:随着镉处理浓度升高,叶片PSⅡ潜在活性(Fv/Fo)和光化学淬灭系数(q P)逐渐减小,最高抑制率分别为43.10%和37.82%,而非光化学淬灭系数(q N)逐渐增加,最大增幅达48.13%;低浓度镉胁迫使臭牡丹幼苗可溶性糖和可溶性蛋白含量分别提高39.01%和73.07%,而高浓度镉则对植株可溶性糖和可溶性蛋白含量产生抑制作用。叶片MDA、脯氨酸含量随镉浓度的增加而上升,其中丙二醛含量在胁迫前期增长平缓,后期增长趋势显著,最高增长率达45.29%。可见臭牡丹对镉胁迫具有一定的适应性,可以通过调节自身光合特性和累积渗透调节物质缓解胁迫伤害。

In order to determine the effect of cadmium on the physiological changes of Clerodendrum bungei seedlings,field experiment was conducted with 5 Cd concentrations as 0,0.1,0.3,0.6,0.9 mmol/L. Based on chlorophyll fluorescence parameters,malondialdehyde（MDA） content,proline content,soluble sugar content and soluble protein content measarements. The results showed that potential photochemical efficiency（Fv/Fo） and chemical quenching coefficient（q P） declined with Cd2＋ concentration increased,the highest rate of inhibition was 43.10% and 37.82%,while non-photochemical quenching coefficient （q N） gradually increased by 48.13%. Low concentration Cd2＋ had promotion effect on the contents of soluble sugar and soluble protein,but high concentration of Cd2＋ had an significant inhibitory effect. With the Cd2＋ stress concentration increased,the contents of MDA and proline in leaves of Clerodendrum bungei increased by 39.01%,73.07%. MDA content changed significantly at high concentration,which increased up to 45.29%. There results suggested that the plant might somewhat adapt to cadmium stress,by adjusting its own the photosynthetic characteristics and osmatic adjustment substance.