3种砧木嫁接对柠檬幼树光合特性的影响

摘要

Photosynthetic characteristics of lemon grafted with different rootstocks were compared to provide some references for selecting suitable rootstock for lemon grafting. Diurnal variation of photosynthetic parameters of mature leaves in two-year-old lemon saplings grafted with three rootstocks (trifoliate, sour tangelo, India lime) were measured by using Lcpro-SD portable photosynthesis system. The results indicate that the photosynthetic characteristics of lemon grafted with three kinds of rootstocks existed significant differences, and the diurnal variations of net photosynthetic rate (Pn) all showed double-peak curves with 'photosynthetic noon break'. The maximum net photosynthetic rate (Pmax) changed from 11.08 μmol·m-2s-1to 13.14 μmol·m-2s-1, and the order of the three rootstocks based on Pnvalue from high to low was YN No.1/ZK, No.4 NM/ZK, No.4 NM/SY, YN No.1/SY, YN No.1/YDLM, No.4 NM/YDLM. 'Yunning No.1' lemon grafted with rootstock of trifoliate had the best photosynthetic property, and Pmax, stomatal conductance (Gs), water use efficiency(Wu),light use efficiency(Lu) and SPAD value were all the highest values. 'Yunning No.1' lemon grafted with trifoliate as rootstock had the best effect at the aspect of photosynthesis efficiency.%比较不同砧木嫁接的柠檬光合特性,为筛选适合柠檬嫁接的砧木提供参考依据.采用 LCpro-SD 全自动便携式光合测定仪分别测定枳壳、酸柚、印度莱檬嫁接的2年生柠檬幼树成熟叶片的光合日变化参数.结果表明:3种砧木嫁接的柠檬其光合特性存在显著差异,3种砧木嫁接的柠檬净光合速率(Pn)日变化曲线均为"双峰"型,存在光合"午休"现象;最大净光合速率(Pmax)在11.08~13.14 μmol·m-2s-1之间变化,净光合速率从大到小依次为:YN1号/ZK > 4号NM/ZK > 4号NM/SY > YN1号/SY > YN1号/YDLM > 4号NM/YDLM;枳砧/云柠1号柠檬的光合性能最好,其最大净光合速率(Pmax)、气孔导度(Gs)、水分利用效率(Wu)、光能利用效率(Lu)和叶片叶绿素相对含量(SPAD值)均最高.从光合效率角度评价,枳壳作为云柠1号柠檬嫁接砧木效果最佳.