【摘要】 利用定样平行配套观测方法 ,研究了龙须草叶片形态结构和光合、蒸腾等生理功能 ,结果表明 :龙须草叶片呈长剑形 ,叶长为 35～ 1 50 cm,最长可达 2 0 0 cm以上 ,叶宽为 0 .1 9～0 .48cm;功能叶结构具有典型的 C4 “花环结构”;上表皮中具有十分发达的保护水分过度蒸腾的“泡状细胞”;上表皮气孔分布密度大于下表皮。功能叶叶绿素 a/ b值为 3.2 8± 0 .2 6。背面叶平均光合强度为 62 .4( CO2 mg/ dm2 · h)、呼吸强度为 3.57( CO2 mg/ dm2 · h)、蒸腾强度为 372 6( H2 O mg/ dm2 · h)、气孔阻力为 0 .2 1 ( sec./ cm)、水分利用效率为 1 6.747。背面叶的光合强度和蒸腾强度明显高于腹面叶。更多还原

【Abstract】 The morophological feastures,anatomical structures and physiological function (photosynthesis,transpiration,respiration,stomatic resistance and water use efficiency) of leaf in Eulaliopsis binata were studied during 1997-1998.The results were as follows:(1) The leaf of Eulaliopsis binata had a long sword blade with length variation from 35 cm to 150 cm and width variation from 0.19 cm to 0.48 cm.(2) The vein was composed of vascular bundle surrounded by the bast fibre and a great deal of fibre was found clos to the lower epidermis.The density of stoma was higher in uper epidermis than in lower epidermis.(3) “Kranz type” was found constituted by the big vascular bundle sheath cells containing the abundant big shaped chloroplasts with the nearby mesophyll cells of the blade which is typical anatomical structure of C 4 plant.(4) The bulliform cells was found crowded on the two sides of midvein and closed to uper epidermis,which prevented the loss of leaf water too much by transpiration.(5) To the functional leaf,the averages of photosynthetic rate,transpiration rate,respiration rate,water use efficiency and stomatic resistance were 62.4 (CO 2 mg/dm 2·h),3726 (H 2O mg/dm 2·h),3.57(CO 2 mg/dm 2·h),16.747 and 0.21 (sec./cm) respectively.The average ratio of “chla/chlb” in functional leaf was 3.28±0.26.更多还原