[Effects of light intensity on growth and photosynthetic characteristics of Tulipa edulis].
OBJECTIVE
Present study was conducted to explore the growth and photosynthetic characteristics of Tulipa edulis under different light conditions (23%, 45%, 63%, 78%, 100% of full sunlight) and to determine the optimum light intensity for growth of T. edulis.


METHODS
The leaf area and biomass indicators as well as reproductive characteristics were measured. The photosynthetic basic parameters and light response curve were determined by a LI-6400XT portable photosynthesis system, and the light response curve characteristic parameters was determined. Additionally, chlorophyll fluorescence parameters were determined by assorted fluorescence leaf chamber of LI-6400XT.


RESULTS
The lowest biomass yield was observed in the 23% and 100% of full sunlight treatments while the highest value was found under the 78% of full sunlight conditions. With the reduction of light availability, the success rate of sexual reproduction, light saturation point (LSP) and light compensation point (LCP) reduced, while apparent quantum yield (AQY) increased. 23% and 45% of full sunlight treatments led to lower photosynthesis rate (Pn) and higher apparent quantum yield (AQY) in comparison with other treatents. The highest photosynthesis rate was observed in the 78% and 100% of full sunlight treatments. In addition, 78% of full sunlight treatments led to highest Fv/Fm, Fv'/Fm', PhiPS II, ETR, and qP.


CONCLUSIONS
T. edulis was able to adapt in a wide range of light intensity, and 78% of full sunlinght was the most suitable light condition for growth of T. edulis.
Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, China.
Hongjian
H
Xu
Zaibiao
Z
Zhu
Qiaosheng
Q
Guo
Zhengjun
Z
Wu
Hongliang
H
Ma
Yuanyuan
Y
Miao
D018533:Biomass; D004307:Dose-Response Relationship, Radiation; D010788:Photosynthesis / Q000528:radiation effects*; D013472:Sunlight; D031447:Tulipa / Q000254:growth & development* / Q000378:metabolism* / Q000528:radiation effects