不同生育阶段燕麦对干旱胁迫的响应

Response of Oat to Drought Stress at Different Growth Stages

设中度干旱(MD,土壤田间最大持水量的55±5%)、重度干旱(SD,土壤田间最大持水量的35±5%)两个处理,研究干旱胁迫对温室盆栽燕麦不同生育阶段(苗期、分蘖期、拔节期)的生长性状、叶绿素荧光参数以及根系形态的影响。结果表明,与正常供水(CK)相比,干旱胁迫处理均显著(P<0.05)降低了燕麦苗期、分蘖期、拔节期3个生育阶段地上部生物量、株高以及叶片光合荧光参数Fv/Fm、Fv/Fo。干旱胁迫下,燕麦根系表现出明显的形态可塑性,苗期通过增加根长、分支数和细根数(直径≤0.48mm)来响应干旱胁迫,分蘖期主要通过减少根长、分支数来响应干旱胁迫,拔节期主要通过减缓各级根系的生长并增加根的分级数来响应干旱胁迫。

In this study,oats were cultured in pots in the greenhouse under two treatments of moderate drought stress(MD,55±5%of soil field maximum water holding capacity)and severe drought stress(SD,35±5%of soil field maximum water holding capacity)during three growth periods(the emergence stage,the tiller stage,the jointing stage).The objective of this research was to study the effects of drought stress on growth traits,chlorophyll fluorescence parameters and root morphological at different growth stages.The results showed that compared with the control(CK),MD and SD treatments both significantly(P<0.05)reduced the aboveground biomass,plant height and leaf photosynthetic fluorescence parameters(Fv/Fm,Fv/Fo)at seedling,tillering and jointing stages of oat.Under drought stress,oat roots showed obvious morphological plasticity.Oats responded to drought stress by increasing root length,number of branches and number of fine roots(diameter≤0.48mm)at seedling stage.At tillering stage,oat mainly responded to drought stress by reducing root length and branch number,slowing down the overall growth of root system and reducing root consumption in response to drought stress.At the jointing stage,oat responded to drought stress mainly by slowing down the growth of all levels of roots and increasing the number of roots.