作　　者： ; ; ; ; ;

机构地区： 广东省农业科学院

出　　处： 《园艺学报》 2003年第5期519-524,共6页

摘　　要： 利用Li 6 40 0光合作用仪对田间条件下 7年生溪蜜柚的光合特性进行了系统研究。结果表明 :( 1)溪蜜柚外围叶片晴天的净光合速率 (Pn)日变化为双峰曲线 ,首峰出现在 8～ 10时 ,次峰值小于首峰值 ,出现在 14时以后 ;阴天呈单峰曲线 ;内膛叶片Pn日变化有双峰、单峰和锯齿形 3种类型。 ( 2 )观测期内Pn季节变化近似双峰曲线。 ( 3)不同月份和不同枝条叶片Pn对光和CO2 响应有较大差别 ,光补偿点和饱和点分别为 16～ 4 6和 10 2 6～ 16 56 μmol·m-2 ·s-1 ,表观量子效率 0 0 172 5～ 0 0 54 31;CO2 补偿点和饱和点分别为 51～ 80和 82 2～ 92 6 μmol·mol-1 ,羧化效率 0 0 176 9～ 0 0 5191;Pn对CO2 的响应进程近似双曲线。 ( 4)Pn与气孔导度、蒸腾速率、光照强度正相关 ,与胞间CO2 浓度负相关 ,与温度、湿度和叶面水气压亏缺的相关性比较复杂。 ( 5)Pn与叶片的叶绿素含量和比叶重之间没有明显相关性。 ( 6 )光合适温为2 4～ 34℃。 The photosynthetic characteristics of leaves in 7-year-old gu anximiyou pomelo variety under field conditions were studied by using the Li-64 00 portable photosynthesis system. The results were as follows: (1)The diurnal v ariation of net photosynthetic rate(Pn) of peripheral leaves in sunny days prese nted bimodal carve, the first peak occurred at 8:00-10:00 , Pn was 15 77μmol·m -2 ·s -1 ,the second peak occurred after 14:00,the value was lower than the first one; In overcast days, the daily change of Pn had one peak , the value approach the first peak value of Pn in sunny days; in both sunny and overcast days, the diurnal variation of Pn of inner leaves showed the one or tw o peak or indention carve.(2)The seasonal variation of Pn also approach bimodal carve by the average of Pn. (3)Among shoots in different months, there were diff erences in the responses of leaves Pn to light intensity and CO 2. The light co mpensate and saturated point of leaves was 16～46μmol ·m -2 ·s -1 and 1026-1656μmol·m -2 ·s -1 respectively,the apparent quantum efficiency between 0 01725 and 0 05 431,these showed that the leaves of guanximiyou had the higher utilization effic iency on weak light and in strong light; the CO 2 compensate and saturated poin t was 51-80μmol·mol -1 and 822-926μm ol·mol -1 respentively,the carboxying efficiency between 0 01769 and 0 0 5191. (4)Pn had obvious positive relationship with Cond,Trm and PAR, most of the m were obvious or remarkable. Pn had obvious negative relationship with Ci, majo rity of them were remarkable. There were complex relationship between Pn and Tai r, Tl, RH, Vpdl. (5)There were no marked relation between Pn and the chlorophy ll content and specific leaf weight (SLW) of leaves. (6)The proper temperature of photosynthesis were 24-34℃.

关 键 词： 琯溪蜜柚 光合特性 生理生态因子 光合作用仪 田间条件

领　　域： [农业科学] [农业科学]