American Journal of Environmental Sciences

Responses in Nitrogen Mass and Nitrogen Metabolism of Wild Sugarcane (Saccharum spontaneum L.) UV-B Radiation Under Field Conditions

Yanqun Zu, Yuan Li, Haiyun Wang and Yongmei He

DOI : 10.3844/ajessp.2013.446.457

American Journal of Environmental Sciences

Volume 9, Issue 6

Pages 446-457

Abstract

Field experiments were conducted to evaluate effects of enhanced UV-B radiation (280-315 nm) on intraspecific responses in nitrogen mass and nitrogen metabolism of six wild sugarcane (Saccharum spontaneum L.) clones. The clones were collected from original sites with different altitudes (4-1780 m above sea-level) and latitudes (18-38°N). The supplemental UV-B radiation was 5.00 kJ⋅m-2, simulating a depletion of 20% stratospheric ozone. Out of the six tested wild sugarcane clones, available Nitrogen (N) contents in soil and N contents in leaves of four wild sugarcane clones decreased significantly. Leaf biomass and leaf N mass of six wild sugarcane clones significantly increased. UV-B radiation significantly decreased N contents and increased biomass and N mass in stems of six wild sugarcane clones. Contents of free amino acid of two wild sugarcane clones (92-11 and 92-36) significantly decreased, whilst that of clones 83-193 and II91-5 significantly increased. Total protein contents of three wild sugarcane clones significantly decreased, whilst that of clone 90-15 significantly increased. Nitrate reductase activities of two clones (92-11 and 90-15) significantly decreased, whilst that of four clones significantly increased. Glutamine synthetase activities of two clones (92-11 and 90-15) significantly increased, while that of clones 83-193 significantly decreased. UV-B radiation might change stem biomass, resulting in changes in N mass in stem and leaves. Results indicate that intraspecific responses in N mass and N metabolism of six wild sugarcane (S. spontaneum) clones differing in UV sensitivity to enhanced UV-B radiation exist under field conditions.

Copyright

© 2013 Yanqun Zu, Yuan Li, Haiyun Wang and Yongmei He. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.