水分和践踏胁迫对结缕草生长及生理生化指标的影响

为探讨草坪耐践踏性与草坪草含水量的关系，研究在不同水分和践踏胁迫下的生长和生理指标的变化，以大田结缕草（Zoysia grass “JD-1”）草坪（2年生）为对象，采用大田裂区设计（践踏胁迫为主区，水分胁迫为副区）布设试验样地，通过模拟践踏和称重控水处理，测定草坪草密度、株高、地上生物量等生长指标和叶片相对电导率、游离脯氨酸含量、丙二醛含量和可溶性糖含量等生理指标。结果表明，水分和践踏胁迫对结缕草生长和生理指标产生明显影响，并且在重度水分胁迫和重度践踏胁迫下的影响有叠加效应；水分胁迫能够使草坪密度下降、株高变矮，地上生物量减少，且随水分胁迫程度增加呈递减变化，各水分处理之间差异显著（P<0.05）；在轻度水分胁迫下，结缕草密度、地上生物量和叶片相对电导率、MDA含量、游离脯氨酸含量和可溶性糖含量在不同的践踏胁迫下的差异不显著（P>0.05）；在无水分胁迫和重度水分胁迫下各指标的差异显著性有所不同。至30 d恢复生长，各指标的变化与处理期变化趋势一致:践踏胁迫后的密度增加，株高生长量和地上生物量的明显增加，与CK相比差异不显著（P>0.05）；而水分胁迫后的密度、株高和地上生物量的差异显著（P<0.05）；叶片相对电导率、MDA含量、游离脯氨酸含量和可溶性糖含量等生理指标与CK相比差异不显著（P>0.05），且都能恢复正常生长水平。表明在一定程度上轻度水分胁迫有助于提高结缕草的耐践踏性。

Effect of Water and Trample Stresses on the Growth Traits and Physiological&Biochemical Indices of Zoysia Grass

Taking the biennial Zoysia japonica(Zoysia grass“JD-1”)growing in the field as the research object,the relationship between the trample resistance of the turf grass and water content was investigated.Changes in the growth and physiological indices under different water and trample stress levels were examined.The experimental sample plots were arranged by Split-Plot Design,in which the trample stress(simulated by trampler)was taken as the main plots,and the water stress(implemented by water control method)as the subplots.Relative indices were measured,including growth indices(turf grass density,height,and the aboveground biomass)and physiological indices(relative conductivity,contents of free proline,malondialdehyde MDA,and soluble sugar).The results showed that water and traffic stresses had significant impacts on the growth traits and physiological indices.Under both heavy trample and water stresses,additive effect was observed.Water stress made the turf density,plant height,and aboveground biomass decreased,the amplitude of the decrease declined with the increase of the intensity of water stresses;significant differences were found among different water treatments(P<0.05).However,under light water stress,the turf density,aboveground biomass,relative conductivity,and the contents of proline,MDA,and soluble sugar had no significant difference among different levels of trample stress(P>0.05),however,under no and heavy water stress,differences in significance of all the indexes were different.Thirty days after the growth recovery,the indexes presented the same change trend with the stress period,i.e.,the density increase,the significant increases of height and the aboveground biomass caused by heavy trample stress were not significantly different with those of the control(P>0.05);while the changes of the density,height and the aboveground biomass resulted from water stress were significantly different with the control(P<0.05);the changes of relative conductivity and the contents of proline,MDA,and soluble sugar resulted from trample stress were not significantly different(P>0.05)with the control,which would recover to normal growth status after the stress was removed.It was concluded that light water stress could increase trample resistance of Zoysia grass.