TITLE Effect of nitrogen on root and shoot relations and gas exchange in winter wheat
AUTHOR Z.P. Shangguan
National Laboratory of Soil Erosion and Dryland Agriculture on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling, Shaanxi Province, 712100, P.R. China
M.A. Shao
National Laboratory of Soil Erosion and Dryland Agriculture on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling, Shaanxi Province, 712100, P.R. China
S.J. Ren
Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi Province, 712100, P.R. China
L.M. Zhang
Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi Province, 712100, P.R. China
Q. Xue
Northwestern Agricultural Research Center, Montana State University, 4570 Montana 35, Kalispell, MT 59901, USA
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ABSTRACT The seedling growth of two drought-resistant wheat varieties was studied under solution culture in a plant growth chamber. The results showed that the shoot dry weight and leaf gas exchange parameters increased with the increase of nitrogen supply, but decreased when nitrogen supply reached a certain level. The optimum nitrogen concentrations for shoot dry weight and gas exchange were different among the varieties. The root growth was negatively correlated with the increase of nitrogen supply. The distribution of root length in different layers was similar for the two varieties. The root length was the longest at the layer of 5-15 cm, the shortest below 15 cm, and in between at the layer of 0-5 cm. The water use efficiency (WUE) decreased with increasing ratio of root to shoot (R/S), while leaf photosynthetic rate tended to increase initially and then decrease. The increase in R/S was unfavorable to increase WUE, and the appropriate R/S for leaf photosynthetic rate was about 0.5.
KEYWORD Coordinate growth; Nitrogen nutrition; Root and shoot relation; Winter wheat;
ARTICLE INFO Botanical Bulletin of Academia Sinica, Volume 45 Number 1 January 2004, page 49-54, 6 pages
PUBLISHER Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, Republic of China