Abstract:

Using pot culture 1-year-old Rhus typhina seedlings as experiment materials and adopting the method of weighing the soil to control the water content,four different levels of water stresses were applied to examine the effect of water stress on the growth and eco-physiology of R.typhina seedlings. The water stresses were the control(CK)、mild water stress(T1)、moderate water stress(T2) and severe water stress(T3).The results showed that height, root collar diameter, biomass accumulation (expressed as total biomass and weight of needles, stem and shoots and roots), taproot length, number of first-order lateral roots of R.typhina seedlings in group of CK were obviously higher than those of group T2 and T3,In group T1 of R.typhina seedlings did not effect Stem weight and total biomass,but seriously decreased shoots and root weight;R.typhina seedlings under extremely low water supply exhibited notably reduced net photosynthetic rate and transpiration rate,which restricted their biomass accumulation and root growth of R.typhina seedlings,while R.typhina seedlings could acclimate to the water regimes by adjusting their water use efficiency. In the whole water treatment period,in group of T1、T2 and T3 had higher content of proline than that of group CK,which had a important function in infiltration modulation. Content of chlorophyll of R.typhina seedlings increased at the beginning of water treatment,it enhanced the compliant ability of water regimes. Because of R.typhina seedlings kept fighting a drought at the beginning of water treatment,after 30 days of water stress,in group of T1、T2 and T3 had lower content of MDA than that of group CK. At the later period of water stress,in group of T1、T2 and T3 of R.typhina seedlings, content of chlorophyll decreased,and content of MDA was a bit higher than that of group CK,which indicated that R.typhina seedlings had less damage.

Key words: Rhus typhina, water stress, growth, eco-physiology