The combined effects of water deficit and heat stress on physiological characteristics of endangered Nouelia insignis

摘要: Dry-hot valley is characterized by water deficit and heat stress which often occur simultaneously in the field. Nouelia insignis has become endangered natural regeneration of species dry-hot limited. Seedlings subjected to each treatment (achievement withholding irrigation for 0, 3 6 days, respectively) were randomly divided into three groups transferred climate chambers set at 25, 40 50 °C 1 h, respectively. Leaf relative content, photosynthetic activity maximum quantum yield photosystem II (Fv/Fm) determined after day recovery decreased significantly, but pigment content catalase (CAT) increased significantly under severe or extreme heat. Soluble sugar moderate stress. Significant interactive effects between found leaf Fv/Fm, non-photochemical quenching coefficient (NPQ), CAT soluble content. Fv/Fm seedlings treated combination did not recover original level recovery. In conclusion, both could lead loss leaves adversely affect plant metabolic activities N. insignis. Particularly, aggravated when occurred simultaneously. Water heat, particularly their combination, might be key factors limited valley.