%0 Journal Article %A GAO Yu-Bao* %A GAO Zeng-Lu %A ZHANG Xiao-Chun %A ZHENG Zhi-Rong %T A Comparative Study of Photosynthetic Characteristics of Caragana davazamcii Between Plants of Different Ages in Huangfuchuan Basin of Ordos Plateau %D 2009 %R 10.7525/j.issn.1673-5102.2009.02.010 %J Bulletin of Botanical Research %P 182-186 %V 29 %N 2 %X The photosynthetic characteristics of Caragana davazamcii plants of different ages were investigated. The net Photosynthetic rate(Pn) and transpiration rate(Tr) of mid-aged plants(5 years old) were higher than those of senile plants(24 years old). The decrease of Pn in senile plants between 12:00-14:00 was caused by non-stomatal factors that impaired photosystem â…¡and photosynthetic capacity of the leaves, while that in mid-aged plants was a consequence of both stomatal and non-stomatal inhibition. The determination of photosynthetic pigment contents showed that the contents of chlorophyll and carotenoid in mid-aged plants were significantly higher than those in senile plants, so that the mid-aged plants had higher Pn, LUE and capcity of intensive radiation adaptation. In addition, the mid-aged plants had higher WUE, which made them more tolerant to drought, so the mid-aged plants were able to adapt to the local envioronments with high temperature and severe drought. %U https://bbr.nefu.edu.cn/EN/10.7525/j.issn.1673-5102.2009.02.010