连续3年UV-B辐射对33个割手密无性系成熟期锤度的影响

Effects of Three Years' Enhanced UV-B Radiation on Birxs of 33 Wild Sugarcane(Saccharum spontaneum L.) Clones at Ripening Stage

在大田栽培和自然光条件下,研究了连续3年模拟紫外辐射(UV-B,280～315nm)增加对33个割手密无性系成熟期锤度的影响。结果表明:(1)UV-B辐射对割手密无性系锤度具有明显的影响;(2)33个割手密无性系锤度对UV-B辐射响应具有明显的差异,在2003年、2004年和2005年,锤度响应范围分别为-27.86%～69.90%、-28.88%～34.58%和-18.90%～26.21%;(3)割手密无性系锤度对UV-B辐射响应具有明显的年际间差异,从选择的10个无性系来看,从2003年、2004年到2005年,6个无性系锤度变化率增加,4个无性系锤度变化率下降。

Field studies were conducted for three consecutive years to determine the potential effect of enhanced ultraviolet-B （UV-B, 280- 315 nm） radiation on birxs （the total solvable material contents in cell） and the intraspecific variation of birxs of 33 wild sugarcane （Saccharum spontaneum L.） clones at ripening stage. Wild sugarcane clones were collected from original sites in China. The supplemental UV-B radiation was 5.00 kJ· m^-2, simulating a depletion of 20% stratospheric ozone at Kunming （25°N, 1950 m）. Out of 33 wild sugarcane clones tested, in general, ultraviolet-B radiation had significant effects on brixs, while intraspecific differences in brixs of wild sugarcane clones under UV-B radiation were observed in 2003, 2004 and 2005, respectively. The responses of birxs to UV-B radiation varied with different years, being -27.86%-69.90%, -28.88%-34.58% and -18.90%-26.21% in 2003, 2004 and 2005, respectively. Considering 10 wild sugarcane clones that were chosen from 33 tested clones in 2003, 2004 and 2005, respectively, the birxs of 6 of them increased, and that of 4 of them decreased under UV-B radiation. Brixes were related with sensitivity of wild sugarcane clones to UV-B radiation. UV-B radiation decreased brixs in tolerant wild sugarcane clones that originated from regions with high UV-B ambient （high elevation）, but increased that in sensitivity ones that originated from regions with low UV-B ambient （high elevation）.