干旱区生态环境知识资源中心

Caragana korshinskii Kom. a dominant member of desert flora in north-western China, is often subjected to aboveground shoot destruction but is very successful in its rapid recovery. We investigated the physiological basis for resprouting by comparing shoot elongation, leaf-nutrient content, pre-dawn leaf-water potential (LWP), root non-structural carbohydrate (TNC), and photosynthetic rate of first-year resprouts with those of adjacent undamaged individuals. C. korshinskii resprouts had a significantly higher rate of shoot elongation. Plant responses associated with enhanced shoot elongation included (1) improved water status, (2) drawing upon more TNC from roots to support aboveground shoot regrowth, (3) enhanced photosynthetic rate owing to improved water status and increased nutrient content in leaves, and (4) allocating more photosynthate to vegetative production without reproduction costs. Maintaining an active root system after shoot removal may be the foundation which engenders these mechanisms underlying rapid regrowth of C. korshinskii in the disturbed environment.