中文摘要：

【目的】研究蔗茅无性系气体交换特性,筛选高光效种质资源,为开展高光效品种培育等相关研究奠定基础。【方法】在自然条件下,利用Li-6400便携式光合仪测定36份蔗茅种质资源的光合气体交换参数,如叶片净光合速率、气孔导度、胞间CO2浓度、蒸腾速率、叶片饱和水汽压亏缺、蒸腾效率、叶片瞬时水分利用效率。【结果】36份蔗茅种质资源平均净光合速率为17.61μmol·m^-2·s^-1数变化为2.28;平均气孔导度为0.15 mol·m^-2·s^-1,倍数变化为2.88;平均胞间CO2浓度为163.49μmol·mol-（-1）,倍数变化为2.29;平均蒸腾速率为2.17 mmol·m^-2·s^-1,倍数变化为1.96;平均叶片饱和水汽压亏缺为1.38 MPa,倍数变化为1.60;平均蒸腾效率为124.43μmol CO2·mol^-1H2O,倍数变化为1.93;平均叶片瞬时水分利用效率为8.12μmol CO2·mmol^-1H2O,倍数变化为1.75。36份蔗茅无性系光合气体交换参数变异系数范围为11.79%—26.79%,其中,气孔导度变异系数最高（26.79%）,净光合速率次之（21.48%）,叶片瞬时利用效率最低（11.79%）,36份蔗茅无性系光合气体交换参数间存在较大差异。净光合速率与蒸腾速率、气孔导度、叶片瞬时水分利用效率呈显著正相关,与叶片饱和水汽压亏缺呈显著负相关;气孔导度与胞间CO2浓度、蒸腾速率呈显著正相关,与叶片饱和水汽压亏缺、蒸腾效率呈显著负相关。环境因子相关分析表明,叶片饱和水汽压亏缺与经度呈正相关,与海拔、纬度呈负相关,依据海拔划分为高海拔和低海拔,高海拔拥有相对较高的光合速率。进一步利用主成分分析选出2个主成分,方差累计贡献率达到89.79%,净光合速率、气孔导度、蒸腾速率即光合效率作为第一主成分的主导因子;胞间CO2浓度、叶片瞬时水分利用效率、蒸腾效率即水分利用效率因子作为第二主成分的主要因子。36份蔗茅无性系材料可划分为五类,分别划分为?

英文摘要：

【Objective】A study on photosynthesis was carried out to examine the variation in gas exchange parameters among Erianthus fulvus clones, aiming at screening germplasm with good photosynthetic capacity and benefiting breeding for varieties with promoted photosynthetic capacity. 【Method】 Li-6400 photosynthesis system was used for gas exchange measurements of 36 clones of Erianthus fulvus at elongating stage.【Result】The each average value of gas exchange parameters was 17.61 μmol·m^-2·s^-1）, 0.15 mol·m^-2·s^-1s）, 163.49 μmol·mo^-1（Ci）, 2.17 mmol·m^-2·s^-1）, 1.38 MPa（VPDL）, 124.43 μmol CO2·mol-（-1）H2O（TE）, 8.12 μmol CO2·mmol^-1H2O（WUE） and the fold change was 2.28, 2.88, 2.29, 1.96, 1.60, 1.93, and 1.75, respectively. Coefficient of variation of gas exchange parameters ranged from 11.79% to 26.79%, in which stomatal conductance had the highest value（26.79%）, followed by the net photosynthetic rate a CV value of 21.48%, water use efficiency exhibited the lowest CV with a value of 11.79%. Statistical analysis showed that there was a significant variation in each gas exchange parameter among the clones. Gas exchange parameter correlation analysis showed that net photosynthesis rate was positively correlated with transpiration efficiency, stomatal conductance, water use efficiency, and a negative correlation with leaf vapor pressure deficit. Stomatal conductance showed a positive correlation with internal CO2 concentration, transpiration rate, and a negative correlation with leaf vapor pressure deficit and transpiration rate. Environmental factors correlation analysis showed that leaf vapor pressure deficit had a significant correlation with longitude, but a significant negative correlation with elevation and altitude. According to the altitude, they were divided into high altitude and low altitude and high altitude of clones showed a better photosynthetic capacity than low altitude. Two principal components were picked up whose cumulative variance proportion was up t