作　　者： (崔之益）; (张宁南）; (杨曾奖）; (徐大平）; (刘小金）; (洪舟）; (肖玉）;

机构地区： 中国林业科学研究院热带林业研究所,广州510520

出　　处： 《生态学杂志》 2017年第9期2529-2534,共6页

摘　　要： 为林下推广种植金花茶(Camellia nitidissima)选择适宜的林分郁闭度和光强,以降香黄檀(Dalbergia odorifera)不同种植密度下套种的金花茶幼树与不同孔径遮阴网下金花茶幼苗为研究材料,分析其光合生理特性。结果表明:光强在小于700μmol·m^(-2)·s^(-1)时,金花茶幼树净光合速率随着光强的降低而降低,气孔导度随着光强的降低呈现先升高后降低的变化趋势,胞间二氧化碳浓度随着光强的降低逐渐升高,蒸腾速率随着光强的降低而降低,水分利用效率随光强的逐渐降低其变动趋势不明显;金花茶气体交换参数间的相关性在幼苗和幼树之间表现出差异,而幼苗与幼树在净光合速率与气孔导度关系上则没有表现出明显差异;不同光强下的金花茶幼树气体交换参数表型可塑性较高,均在0.8以上。本研究结果表明,金花茶幼树在700μmol·m^(-2)·s^(-1)光强下会发生光抑制,因此金花茶的林下推广种植,应选择郁闭度30%以上的林分,避免强光胁迫,影响生长。 To investigate the suitable canopy density and light intensity for the cultivation of Camellia nitidissima in the understory planting, the C. nitidissima saplings grown under Dalbergia odorifera with different planting densities, and the C. nitidissima seedlings under shading network of different aperture sizes were chosen as study materials, to study the photosynthetic physiological characteristics of C. nitidissima. The results showed that the net photosynthesis rate decreased with decreasing the light intensity when the light intensity was below 700 μmol·m^-2·s^-1, stomatal conductance tended to increase at first and then decrease, intercellular CO2 concentration increased, transpiration rate decreased, and water use efficiency varied nonsignificantly with decreasing light intensity. The correlation of leaf gas exchange parameters showed difference between seedlings and saplings, whereas there was no significant difference in the relationship of net photosynthesis rate with stomatal conductance between seedlings and saplings. The phenotypic plasticity of leaf gas exchange parameters of C. nitidissima saplings was high, being over 0.8. Our results showed that there was photoinhibition observed in C. nitidissima saplings under the light density of 700 μmol·m^-2·s^-1. So we suggest that the cultivation of C. nitidissima in the understory planting should be conducted in forest stands with above 30% canopy density to avoid growth inhibition by light stress.

关 键 词： 金花茶 光强 气体交换参数 气孔限制 表型可塑性