【摘要】 为了探究遮阴处理对玻璃苣光合特性的影响以及其适宜生长的光照强度,以玻璃苣为试材,设置全光照、30%、50%、70%4个不同的遮阴处理,对其叶绿素含量、光合特性、光响应曲线及荧光参数进行相关研究。研究结果表明:随着遮阴程度的增加,玻璃苣叶片的叶绿素a、叶绿素b及叶绿素总量呈上升趋势,70%遮阴条件下达到最大值,分别为全光照处理下的1.55、1.67、1.58倍,叶绿素a/b呈下降趋势,70%遮阴处理下值最小,与全光照处理相比下降了5.09%;而类胡萝卜素则呈现先上升后下降的趋势,50%遮阴处理下达到最大值,比全光照提高了26.67%。玻璃苣叶片的净光合速率、气孔导度、蒸腾速率、光补偿点、光饱和点及暗呼吸速等均随着遮阴强度的增加呈下降趋势; Fm/Fo、Fv/Fo、Fv/Fm等荧光参数则随着遮阴强度的增加呈现先上升后下降的趋势, 30%遮阴条件下达到最大值;对其PSⅡ反应中心活性来说,ABS/RC、TRo/RC随遮阴强度的增加呈上升趋势,ETo/RC呈现先上升后下降的趋势,在50%遮阴条件下达到最大值,而DIo/RC则呈现先下降后上升的趋势,于30%遮阴条件下达到最小值。综上所述,玻璃苣适宜生长在遮阴30%的光照条件。更多还原

【Abstract】 In order to explore the effect of shading treatments on photosynthetic characteristics of Borago officinale and its suitable light intensity for growth, we used annual Borago officinalis as experimental material, set up full light, 30%,50%, and 70% of 4 different shade treatments, and their chlorophyll content, photosynthetic characteristics, light response curves, and fluorescence parameters were studied. The results of the study showed that: with the aggravation of shade, the chlorophyll a, chlorophyll b and chlorophyll content of Borago officinalis were increasing. The maximum value, obtained under 70% shade conditions, was 1.55, 1.67 and 1.58 times respectively of the value under full light treatment. However,chlorophyll a/b showed a downward trend, and chlorophyll a/b was the smallest under 70% shading condition, which was5.09% lower than that of full light treatment. The carotenoid increased first and then decreased, and reached the maximum under 50% shading treatment, which was 26.67% higher than that of the whole light. The Pn, Gs, Tr, light compensation point, light saturation point and dark respiration rate of Borago officinalis showed a downward trend with the increase of shading intensity. For its fluorescence parameters, Fm/Fo, Fv/Fo, and Fv/Fm showed a tendency of rising first and then decreasing with increasing shading intensity, reaching a maximum at 30% shade. For the activity of its PSII reaction center,ABS/RC, TRo/RC increase with the increase of shading intensity, Eto/RC showed a trend of rising first and then decreasing,reaching a maximum at 50% shade, and DIo/RC showed a trend of falling first and then rising, reaching a minimum at 30%shade. In summary, the Borago officinalis is suitable for living under 30% shading.更多还原