盐碱胁迫对虎尾草生长的影响

The Growth Effect of Saline-alkali Stress on Chloris virgata

以天然抗盐碱植物虎尾草为材料,用中性盐NaCl、Na2SO4和碱性盐NaHCO3、Na2CO3按不同比例混合,模拟出12种盐碱强度各不相同的天然盐碱生态条件,并以此对虎尾草幼苗进行胁迫处理.通过测定丙二醛的含量以及植物的干鲜重,来分析盐碱胁迫对虎尾草生长的影响.结果表明:随着盐浓度的增加,盐胁迫组的含水量先上升而后下降,而碱胁迫组的含水量则一直下降,说明低浓度的盐胁迫对虎尾草的生长反而具有一定的促进作用,但碱胁迫对其生长的抑制作用大于盐胁迫.随着盐胁迫强度的增大,盐胁迫和碱胁迫均造成虎尾草MDA含量逐渐升高.其中在盐胁迫状况下,MDA含量增张幅度不大且平缓,而碱胁迫下特别是当碱胁迫强度达到160mmol.L-1以上时,MDA含量由相对平缓转而急剧上升,且明显超过盐胁迫.实验结果证明:盐胁迫和碱胁迫是两种不同性质的胁迫,碱胁迫对生长的抑制作用大于盐胁迫.在本实验条件下.以上可以说明虎尾草具有较高的抗盐碱性.

Natural saline-alkali resistance plant Chloris virgata was used as material in this Experiment, Two neutral salts （NaCI and Na2SO4） and two alkaline salts （NaHCO3 and Na2CO3） were mixed in various proportionsn,simulated 12 mixed salt and alkaline intensities with different nature saline-alkali ecological conditions , above discussed treatment was used for seedling of Chloris virgata. Then analysed the growth effect of saline-alkali stress on Chloris virgata by determining malondialdehyde, fresh and dry weight of plant. Result showed that salt stress treatment group＇s water content rised firstly and decreased later with increasing salinity, but the water content of alkati stress treatment group was decreased all the time. Tnis result indicated that certain low salinity has promoting effect on growth of Chloris virgata, but the inhibition effect of alkali stress was greater than that of salt stress. MDA content was rised gradually under saline and alkali stress with increasing stress intensity. And the rang of increased MDA content was relatively small and mild under salt stress,but under alkali stress , （especially alkali stress intensity above 160 mmol·L^-1） ,MDA content was converted from relatively mild to remarkable increasing and evidently exceeded that of salt stress. The experiment indicated that alkali salt stress and neutral salt stress are actually two distinct kinds of stresses, and the inhibition effect of alkali stress was greater than that of salt stress. In this experiment, cell membrane of seeding was not hurt under salt stress and low intensity alkalic stress, but injury degrees increased shaply under high intensity alkalic stress. Aboved results demonstrated that has relative higher saline-alkali resistance.