Effects of precipitation pattern change on non-structural carbohydrates in different organs of Cunninghamia lanceolata seedlings
[Objective]Frequent droughts caused by global temperature rise and precipitation pattern change have significant impacts on forest ecosystems,so information of plant water utilization and adaptation during and after droughts is crucial.[Method]The seedlings of Cunninghamia lanceolata were used as test material.A two-factor controlled experiment with 4 precipitation amount and 2 precipitation intervals gradients was set to investigate the response of non-structural carbohydrates(NSC)and related fractions content in different organs that suffer different precipitation amount and intervals.[Result]With the decrease of precipitation,NSC content of the seedlings showed an overall trend of firstly increasing and then decreasing in absorbing roots,transport roots,branches and leaves,and continuous decreasing in branches and trunks.C.lanceolata seedlings increased NSC content in transport roots,absorbing roots,leaves and branches,while hydrolyzed and converted the starch from the absorbing roots to soluble sugars to regulate intracellular water potentials;soluble sugars content showed an overall trend of continuous decreasing in transport roots and trunks,and an overall trend of firstly increasing and then decreasing in absorbing roots,leaves and branches;starch content of all organs showed an overall trend of firstly increasing and then decreasing.When precipitation was too low,C.lanceolata seedlings would consume NSC to preferentially meet the survival needs of absorbing roots,which led to a significant decrease of NSC content in transport roots,branches and twigs(P＜0.05).When precipitation intervals increased,NSC content in leaves and transport roots of the seedlings increased significantly(P＜0.05);soluble sugar content of leaves decreased significantly(P＜0.05),and soluble sugar content of transported roots increased significantly(P＜0.05).[Conclusion]To improve the survival of C.lanceolata plantation forests under changes in precipitation patterns,soil water content should be maintained at more than 50％of the average monthly precipitation in the local multi-year dry season,and watering intervals can be extended in areas with higher precipitation.[Ch,3 fig.1 tab.51 ref.]
万方数据
维普
