野外连续两年增强UV-B辐射对8个割手密无性系叶片MDA含量的影响*

 研究了大田栽培和自然光条件下，连续两年模拟UV-B辐射（280～315 nm，5.00 kJ/m²）增强对8个割手密无性系叶片丙二醛（MDA）含量的影响。UV-B辐射对割手密叶片MDA含量有显著的影响，8个割手密无性系叶片MDA含量对增强UV-B辐射存在种内差异。5个无性系叶片MDA含量有明显增加的趋势，分别为I91-97，I91-38，Ⅱ91-116，93-25，90-22；1个无性系MDA含量变化不明显（Ⅱ91-93），2个无性系MDA含量有降低的趋势，分别为Ⅱ91-98，92-11。UV-B辐射对割手密叶片MDA含量的影响具有年际间差异。UV-B辐射对割手密叶片MDA含量的影响存在生育期之间的差异，为伸长期>成熟期>分蘖期。

Effect of Enhanced Ultraviolet-B Radiation on MDA of 8 Wild Sugarcane (Saccharum spontaneum L. ) Clones under Field Conditions for Two Consecutive Years

Field studies were conducted to test the effect of enhanced ultraviolet-B （UV-B, 280～315 nm, 5.0 kJ/m²） radiation on the MDA contents of eight wild sugarcane clones under field conditions in 2003 and 2004. The UV-B radiation had significant effect on MDA contents of eight elongation of wild sugarcanes. Intraspecific responses of 8 wild sugarcane clones to enhanced UV-B radiation were observed. Increase in MDA contents of 5 wild sugarcane clones （I91-97, I91-38,Ⅱ91-116,93-25,90-22）,No change in MDA contents of Ⅱ91-93 and decrease in MDA contents of 2 wild sugarcane clones （Ⅱ91-98，92-11） was observed.The response difference was obvioused between 2003 and 2004. Response sensitivities of MDA contents of 8 wild sugarcane clones to UV-B radiation in different stages had the following sequence: elongation > ripening > tillering both in 2003 and 2004.