核桃光合作用特性的初步研究

Preliminary study on photosynthetic characteristics of walnut

以短枝型核桃品种圃 5 0和普通型品种鲁光为对象 ,用CIRAS -1光合仪测定其净光合效率。结果表明 ,2个品种的光饱合点均为 1 40 0 μmol·m- 2 ·s- 1,光合速率日变化呈双峰曲线 ,第 1次高峰出现在 1 1时前后 ,第 2次在 1 5时前后 ,2次高峰间呈现“低谷” ,表明二者都有“光合午休”现象。圃 5 0的净光合速率峰值(CO2 )为 1 5 .7μmol·m- 2 ·s- 1,鲁光为 1 4.0 μmol·m- 2 ·s- 1。圃 5 0的光补偿点为 60 μmol·m- 2 ·s- 1,鲁光为 1 0 0 μmol·m- 2 ·s- 1,可作为确定栽植密度和树体枝叶留量的依据。

The photosynthetic and stomatal characteristics of walnut were comparatively studied between spur type cultivar'Pu 50'and common cultivar 'Luguang'with photosynthesis analyser CIRAS-1. The curves of diurnal variation of net photosynthesis rates (Pn) were twin-peaked, occurring at 11:00 and 15:00, with peak value being 15.7 and 14.0 μmol·m -2 ·s -1 , respectively. The light saturation point for Pn in both cultivars was 1400 μmol·m -2 ·s -1 . The light compensation of 'Pu 50'was 60 μmol·m -2 ·s -1 , whereas that of 'Luguang' was 100 μmol·m -2 ·s -1 , which could be serve as a guide to determine the planting density and foliage density.