干旱胁迫对伊犁绢蒿幼苗生长及叶片解剖结构的影响

Effects of Drought Stress on Growth and Leaf Anatomical Structure of Seriphidium transiliense seedlings

为探究干旱胁迫对伊犁绢蒿(Seriphidium transiliense)幼苗生长及叶片解剖结构的影响,本研究采用控水实验,对培养45 d后的幼苗进行持续干旱胁迫处理,测定幼苗的株高、根长、地上、地下生物量以及叶片解剖结构。结果表明:随着干旱胁迫程度的加剧,幼苗地上部分生长逐渐减缓,地下部分生长和根冠比则持续增加。当土壤相对含水量降至6.38%时,株高和地上生物量较对照分别降低了73.83%和73.05%(P<0.01),而根长、地下生物量和根冠比较对照分别增加了6.09%,67.92%和527.49%(P<0.01)。随着干旱胁迫程度的加剧,叶片厚度、上下表皮细胞厚度、维管束直径均呈先增后降趋势,而上下角质层厚度则表现出逐渐增加的趋势,栅栏组织呈逐渐下降趋势。综上所述,伊犁绢蒿幼苗通过调节地上部分和地下部分的生长以及叶片解剖结构的变化来应对干旱胁迫。

In order to explore the effects of drought stress on growth and leaf anatomical structure of Seriphidium transiliense seedlings,the 45 d old seedlings were treated with persistent drought stress using the potting method.The plant height,root length,aboveground and underground biomass and leaf anatomical structure were measured.The results showed that with the increased of drought stress,the aboveground growth of seedlings gradually slowed down,while underground growth and the root to shoot ratio continuously increased.When the relative soil water content decreased to 6.38%,plant height and above ground biomass decreased by 73.83%and 73.05%,respectively,compared with control(P<0.01),while root length,underground biomass,and the root to shoot ratio increased by 6.09%,67.92%,and 527.49%,respectively,compared with control(P<0.01).With the increased drought stress,leaf thickness,upper and lower epidermis cell thickness and vascular bundle diameter first increased and then decreased,upper and lower cuticle thickness increased continuously,and the palisade tissue decreased continuously.In summary,S.transiliense seedlings responded to drought stress by regulating the relative growth of aboveground and underground as well as changing leaf anatomical structure.