引种杨树无性系的光合特性比较

摘要

[Objective]This experiment was conducted to compare the photosynthetic characteristics of introduced poplar clones to provide a scientific basis for breeding and promoting excellent poplar clones in poplar planting areas.[Method]Li-6400XT portable photosynthetic system was used to measure the photosynthetic parameters of seven one-year-old introduced poplar clone seedlings including D5-9,D5-9,D5-20,D5-26,171,174,177 and 197 in natural condi-tions in Yili,Xinjiang, and comparative analysis was carried out between them and four local polar varieties.[Result]The diurnal variations of net photosynthetic rate(Pn)for the seven introduced poplar clones all presented double-peak curves. There was obvious midday depression of photosynthesis, which occurred in D5-26 and 171 due to stomatal limitation, while the rest clones were not impacted by stomatal limitation and non-stomatal limitation. D5-9 and 174 were poplar clones of high water use efficiency(WUE)and high light use efficiency(LUE),D5-20 and 197 were of medium WUE and medium LUE,D5-26,171,and 177 were of high WUE and low LUE. Pn of different clones were affected by photosyn-thetically active radiation(PAR),stomatal conductance(Gs)and transpiration(Tr)to different extents.[Conclusion]Poplar clone D5-9 has high photosynthetic ability and advantages in leaf area and growth,making it more suitable for the ecologi-cal environment in Yili. Therefore, cultivation of D5-9 can be promoted in Yili and other poplar planting areas with similar ecological environment as Yili.%[目的]比较引种杨树无性系苗期的光合生理特性,为杨树种植区选育和推广优良杨树无性系提供科学依据.[方法]使用Li-6400XT便携式光合仪,测定新疆伊犁地区自然条件下引种的D5-9、D5-20、D5-26、171、174、177和197等7个杨树无性系1年生苗木的光合参数,并与4个本地杨树品种进行比较分析.[结果]7个引种杨树无性系1年生苗木的净光合速率(Pn)日变化均为双峰曲线,并存在明显的光合午休现象;D5-26和171出现光合午休是由于气孔限制的影响,其余无性系不受气孔限制和非气孔限制调控;D5-9和174属高水分利用效率(WUE)、高光能利用效率(LUE)无性系,D5-20和197属中等WUE、中等LUE型无性系;D5-26、171和177属高WUE、低LUE型无性系;不同无性系的Pn分别受光合有效辐射(PAR)、气孔导度(Gs)和蒸腾速率(Tr)不同程度的影响.[结论]杨树无性系D5-9具有较高光合能力,叶面积和生长量等优势明显,更适应伊犁地区的生态环境,可在伊犁地区及与伊犁地区生态环境相似的杨树种植区推广种植.