关键词: Incarvillea delavayi , Photosynthetic rate , Leaf traits , Water availability

Abstract: Photosynthesis and leaf traits of Incarvill delavayi subjected to water stress were compared in Shangri-La and Kunming to develop effective strategy for domestication and cultivation. The results showed that photosynthetic rate ( P_n ) decreased with the decreasing water availability at both study sites. After transplanted from Shangri-La to Kunming, the photosynthetic rate (P_n ) decreased under the same water availability condition, and the content of chlorophyll and Chl a/b ratio had no significant difference, but the leaf N content per unit area increased. The decrease in stomatal conductance,
mesophyll conductance and lower nitrogen partitioning coefficients in photosynthetic apparatus contributed to the lower photosynthetic rate in Kunming. Furthermore, the response of photosynthetic performances and leaf traits of I. delavayi subjected to water availability in Kunming was not as sensitive as that in Shangri-La. Interestingly, the growth of I. delavayi in
Kunming had a water availability threshold ( 40% soil field capacity) ; if soil water availability lower than this threshold, the relative growth rate became negative. The results showed that this species could be introduced to cultivate successfully at lower altitude .

Key words: Incarvillea delavayi