Leaf orientation, incident sunlight, and photosynthesis in the alpine species Suassurea superba and Gentiana straminea on the Qinghai-Tibet Plateau

NWIPB OpenIR

	Leaf orientation, incident sunlight, and photosynthesis in the alpine species Suassurea superba and Gentiana straminea on the Qinghai-Tibet Plateau
	Cui, XY ; Tang, YH ; Gu, S ; Shi, SB ; Nishimura, S ; Zhao, XQ
	2004-05-01
发表期刊	ARCTIC ANTARCTIC AND ALPINE RESEARCH ; Cui XY, Tang YH, Gu S, Shi SB, Nishimura S, Zhao XQ. Leaf orientation, incident sunlight, and photosynthesis in the alpine species Suassurea superba and Gentiana straminea on the Qinghai-Tibet Plateau.ARCTIC ANTARCTIC AND ALPINE RESEARCH,2004,36(2):219-228
摘要	The extremely high level of solar radiation on the Qinghai-Tibet Plateau may induce photoinhibition and thus limit leaf carbon gain. To assess the effect of high light, we examined gas exchange and chlorophyll fluorescence for two species differing in light interception: the prostrate Saussurea superba and the erect-leaved Gentiana straminea. In controlled conditions with favorable water and temperature, neither species showed apparent photoinhibition in gas exchange measurements. In natural environment, however, their photosynthetic rate decreased remarkably at high light. Photosynthesis depression was aggravated under high leaf temperature or soil water stress. Relative stomatal limitation was much higher in S. superba than in G. straminea and it remarkably increased in the later species at midday when soil was dry. F-v/F-m as an indicator for photoinhibition was generally higher in S. superba than in the other species. F-v/F-m decreased significantly under high light at midday in both species, even when soil moisture was high. F-0 linearly elevated with the increment of leaf temperature in G. straminea, but remained almost constant in S. superba. Electron transport rate (ETR) increased with photosynthetically active photon flux density (PPFD) in S. superba, but declined when PPFD was high than about 1000 mumol m(-2) s(-1) in G. straminea. Compared to favorable environment, the estimated daily leaf carbon gain at PPFD above 800 mumol m(-2) s(-1) was reduced by 32% in S. superba and by 17% in G. straminea when soil was moist, and by 43% and 53%, respectively, when soil was dry. Our results suggest that the high radiation induces photoinhibition and significantly limits photosynthetic carbon gain, and the limitation may further increase at higher temperature and in dry soil.; The extremely high level of solar radiation on the Qinghai-Tibet Plateau may induce photoinhibition and thus limit leaf carbon gain. To assess the effect of high light, we examined gas exchange and chlorophyll fluorescence for two species differing in light interception: the prostrate Saussurea superba and the erect-leaved Gentiana straminea. In controlled conditions with favorable water and temperature, neither species showed apparent photoinhibition in gas exchange measurements. In natural environment, however, their photosynthetic rate decreased remarkably at high light. Photosynthesis depression was aggravated under high leaf temperature or soil water stress. Relative stomatal limitation was much higher in S. superba than in G. straminea and it remarkably increased in the later species at midday when soil was dry. F-v/F-m as an indicator for photoinhibition was generally higher in S. superba than in the other species. F-v/F-m decreased significantly under high light at midday in both species, even when soil moisture was high. F-0 linearly elevated with the increment of leaf temperature in G. straminea, but remained almost constant in S. superba. Electron transport rate (ETR) increased with photosynthetically active photon flux density (PPFD) in S. superba, but declined when PPFD was high than about 1000 mumol m(-2) s(-1) in G. straminea. Compared to favorable environment, the estimated daily leaf carbon gain at PPFD above 800 mumol m(-2) s(-1) was reduced by 32% in S. superba and by 17% in G. straminea when soil was moist, and by 43% and 53%, respectively, when soil was dry. Our results suggest that the high radiation induces photoinhibition and significantly limits photosynthetic carbon gain, and the limitation may further increase at higher temperature and in dry soil.
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/35603
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Cui, XY,Tang, YH,Gu, S,et al. Leaf orientation, incident sunlight, and photosynthesis in the alpine species Suassurea superba and Gentiana straminea on the Qinghai-Tibet Plateau[J]. ARCTIC ANTARCTIC AND ALPINE RESEARCH, Cui XY, Tang YH, Gu S, Shi SB, Nishimura S, Zhao XQ. Leaf orientation, incident sunlight, and photosynthesis in the alpine species Suassurea superba and Gentiana straminea on the Qinghai-Tibet Plateau.ARCTIC ANTARCTIC AND ALPINE RESEARCH,2004,36(2):219-228,2004.
APA	Cui, XY,Tang, YH,Gu, S,Shi, SB,Nishimura, S,&Zhao, XQ.(2004).Leaf orientation, incident sunlight, and photosynthesis in the alpine species Suassurea superba and Gentiana straminea on the Qinghai-Tibet Plateau.ARCTIC ANTARCTIC AND ALPINE RESEARCH.
MLA	Cui, XY,et al."Leaf orientation, incident sunlight, and photosynthesis in the alpine species Suassurea superba and Gentiana straminea on the Qinghai-Tibet Plateau".ARCTIC ANTARCTIC AND ALPINE RESEARCH (2004).