西南师范大学学报（自然科学版）
西南師範大學學報（自然科學版）
서남사범대학학보（자연과학판）
JOURNAL OF SOUTHWEST CHINA NORMAL UNIVERSITY
2014年
9期
66-72
,共7页
花生%UV-B辐射增强%气体交换%叶绿素荧光%超微结构
花生%UV-B輻射增彊%氣體交換%葉綠素熒光%超微結構
화생%UV-B복사증강%기체교환%협록소형광%초미결구
A rachis hypogaea%enhanced UV-B radiation%gas exchange%chlorophyll fluorescence%ultra-structure
该文研究了在接受增强强度为54μW/cm2的U V-B辐射处理3 d后（每天处理8 h ），花生幼苗光合作用相关参数和叶绿体超微结构的变化．结果表明：在UV-B处理3 d结束后，叶绿素a和叶绿素（a＋ b）均显著下降，同时气体交换参数也受到显著影响，表现出净光合速率（Pn）降低了35.42％，气孔导度（Gs）和气孔限制值（Ls）分别下降了28.12％和20.25％，而胞间CO2摩尔分数（Ci）却上升了16.22％，较对照有显著性差异．同样，荧光参数Fv/Fm和 Fv/F0均显著降低．但U V-B处理1 d和2 d后，以上各指标的变化与对照差异不显著．透射电子显微镜（T EM ）图像显示，叶绿体膜肿胀、基质类囊体解体，光合化产物淀粉粒数目和大小减少．叶绿体超微结构的变化可能是叶绿素体积质量分数和光合速率降低的重要原因．
該文研究瞭在接受增彊彊度為54μW/cm2的U V-B輻射處理3 d後（每天處理8 h ），花生幼苗光閤作用相關參數和葉綠體超微結構的變化．結果錶明：在UV-B處理3 d結束後，葉綠素a和葉綠素（a＋ b）均顯著下降，同時氣體交換參數也受到顯著影響，錶現齣淨光閤速率（Pn）降低瞭35.42％，氣孔導度（Gs）和氣孔限製值（Ls）分彆下降瞭28.12％和20.25％，而胞間CO2摩爾分數（Ci）卻上升瞭16.22％，較對照有顯著性差異．同樣，熒光參數Fv/Fm和 Fv/F0均顯著降低．但U V-B處理1 d和2 d後，以上各指標的變化與對照差異不顯著．透射電子顯微鏡（T EM ）圖像顯示，葉綠體膜腫脹、基質類囊體解體，光閤化產物澱粉粒數目和大小減少．葉綠體超微結構的變化可能是葉綠素體積質量分數和光閤速率降低的重要原因．
해문연구료재접수증강강도위54μW/cm2적U V-B복사처리3 d후（매천처리8 h ），화생유묘광합작용상관삼수화협록체초미결구적변화．결과표명：재UV-B처리3 d결속후，협록소a화협록소（a＋ b）균현저하강，동시기체교환삼수야수도현저영향，표현출정광합속솔（Pn）강저료35.42％，기공도도（Gs）화기공한제치（Ls）분별하강료28.12％화20.25％，이포간CO2마이분수（Ci）각상승료16.22％，교대조유현저성차이．동양，형광삼수Fv/Fm화 Fv/F0균현저강저．단U V-B처리1 d화2 d후，이상각지표적변화여대조차이불현저．투사전자현미경（T EM ）도상현시，협록체막종창、기질류낭체해체，광합화산물정분립수목화대소감소．협록체초미결구적변화가능시협록소체적질량분수화광합속솔강저적중요원인．
The impact of UV-B radiation on photosynthetic related parameters and chloroplast ultrastruc-ture have been studied in A rachis hypogaea ,after an enhanced UV-B irradiation performed 8 h per day for 3 days with a ultraviolet light (280 -320 nm ) that maintained about 54 μW/cm2 radiation .Contents of chlorophyll a and chlorophyll (a+b) have significantly declined after radiation for 3 days ,concomitantly , gas exchange parameters were significantly affected ,showing a 35 .42% reduction in net photosynthesis (Pn) ,28 .12% in stomatal conductance(Gs) and 20 .25% in stomata limitation(Ls) .However ,intercellu-lar CO2 concentration(Ci) is increased by 16 .22% ,showing significant difference with that in control ,at the end of the 3 days UV-B treatment .Similarly ,the fluorescence parameters of Fv/Fm and Fv/F0 have also been significantly reduced .However ,the differences of above indexes are not significant compared with the control treated with UV-B after 1 and 2 days .Transmission electron microscope (TEM ) images have revealed that chloroplast membranes is swelled and disintegrated ,and stromal thylakoids are relaxed and parallel to each other ,which might be responsible for worse performance of the photosynthesis ,as a result ,the size and number of starch grains decreased .The change of chloroplast ultrastructure may be the important cause of the decrease of chlorophyll content and photosynthetic rate .
