[Effects of light intensity on photosynthesis and dry matter production of flue-cured tobacco at its seedling stage].
Taking flue-cured tobacco Yunyan 87 as test material, this paper studied its photosynthesis and dry matter production at seedling stage under 100%, 88%, 72%, and 62% natural light intensities. At noon of sunny days, 100% natural light intensity inhibited the photosynthesis, while proper shading (88% natural light intensity) could eliminate the inhibition, and the daily photosynthesis was significantly higher than other treatments. Shading reduced the light saturation point and compensation point, enhanced the apparent quantum yield of photosynthesis and the net photosynthetic rate under weak light, increased the chlorophyll a and chlorophyll b contents, but decreased the chlorophyll a/b and cartenoids contents. Under 88% natural light intensity, tobacco seedlings had higher light saturation point, lower compensation point, higher suitability to the change of light intensity, and higher photosynthetic potentiality. 100% natural light intensity was more advantageous to the transfer of dry matter and soluble sugar to stem, while 88% natural light intensity was more beneficial to the transfer of dry matter and soluble sugar to root. Under the conditions of this experiment, proper shading (88% natural light intensity treatment) could improve the seedling quality of flue-cured tobacco.
College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. wangrui2999@126.com
Rui
R
Wang
Guo-Shun
GS
Liu
Guo-Hua
GH
Chen
De-En
DE
Xiang
Yun-Ping
YP
Wu
D002241:Carbohydrates / Q000032:analysis*; D010788:Photosynthesis / Q000502:physiology*; D036226:Seedlings / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects; D013472:Sunlight; D014026:Nicotiana / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects
D002241:Carbohydrates