核桃两种树形光合荧光特性的比较

Comparison of Two Kinds of Tree Shape on Photosynthetic Fluorescence Characteristics of Walnut

以4年生‘温185号’核桃为试材,比较了主干形与自然开心形2种树形核桃的光合及荧光特性差异。结果表明:2种树形核桃净光合速率(Pn)日变化、蒸腾速率(Tr)日变化、气孔导度(Gs)日变化均呈不对称"双峰"曲线,净光合速率(Pn)日变化峰值分别出现在10:00与16:00左右,且首次峰值比第2次峰值分别高61.29%、51.75%,最大净光合速率分别为主干形15.22μmol·m^(-2)·s^(-1),自然开心形14.39μmol·m^(-2)·s^(-1),14:00出现明显"午休"现象;胞间CO_2浓度(Ci)日变化在净光合速率降低时反而呈现升高趋势;2种树形核桃初始荧光(Fo)与荧光淬灭系数(qP)存在显著相关性。

The photosynthetic and fluorescence characteristics of two kinds of tree shape of walnut were compared with the 4-year-old‘Wen 185＇walnut as the test material.The results showed that,the two kinds of tree walnut that diurnal variation of net photosynthetic rate（Pn）,transpiration rate（Tr）and stomatal conductance（Gs）were asymmetrical‘bimodal curve＇,the net photosynthetic rate（Pn）diurnal variation of peak appeared at around10：00and 16：00,and the first peak than the second peak were high 61.29%,51.75%,and the maximum net photosynthetic rate were the main stem form 15.22μmol·m-2·s-1,open centre model 14.39μmol·m-2·s-1,14：00appeared obvious‘noon break＇phenomenon.The diurnal variation of intercellular CO2concentration（Ci）showed a trend of increasing with the decrease of net photosynthetic rate.The initial fluorescence（Fo）and the fluorescence quenching coefficient（qP）of the two kinds of walnut were significantly correlated with the fluorescence quenching coefficient.