Effects of saline alkali stress and nitrogen supply on germination and seedling growth of Suaeda salsa
WANG Qian;XIAO Liang;TANG Xiang-Yu;XU Qing;YI Hua-Peng;TIAN Hai-Feng;Institute of Mountain Hazards and Environment,Chinese Academy of Sciences;College of Resources and Environment,University of Chinese Academy of Sciences;School of Geography and Planning,Ludong University;
The effects of different substrates;distilled water,pearlite and saline-alkali soil and saline-alkali stress on seed germination and seedling growth of Suaeda salsa was investigated.Increasing levels of saline alkali stress significantly decreased seed germination of S.salsa.Salt content ranging from 0.00%-3.60% resulted in germination %falling from 89%to 0%linearly.The seed germination rate in the soil was lower than those in water and perlite by 8.00% when salt content was below 1.20%.Above 1.20% salt germination in different substrates were not different.The effect of substrate on seed germination is more important than salinity at salt contents below 1.20%,but salinity controls seed germination at salt contents above 1.20%.Seedling emergence increased to a peak value(70%)with the increase of salt content up to 1.00%and then declined gradually to 0%at salt concentrations above 1.00%.It appears that an optimal level of salinity is necessary for S.salsaseedlings to achieve a high survival rate.Salinity plays a dominant role for S.salsaduring the growth period from bud to seedling stage and determines the formation of S.salsacommunity.Higher or lower salinity than optimum may result in the replacement of S.salsaby other plant species and consequently changes to zonal vegetation communities.When soil salinity is at an optimal level,nitrogen can effectively promote the growth of S.salsa.Elevated salt supply may hamper nitrogen uptake by S.salsa.The nitrogen required to maintain optimum growth of S.salsa may vary with salinity.Therefore,both salinity and nitrogen should be considered when utilising S.salsa as the pioneer species to restore the severely degraded saline soil in the Yellow River Delta.
【Fund】： “十二五”国家科技支撑计划项目课题子专题(2011BAC09B05);; 中国科学院“百人计划”和四川省“百人计划”资助
【CateGory Index】： S647
【CateGory Index】： S647