作　　者： ; ; ; ;

机构地区： 中国热带农业科学院科技信息研究所

出　　处： 《热带作物学报》 2013年第4期685-689,共5页

摘　　要： 采用盆栽试验设置正常供水、中度干旱和重度干旱3种处理,研究华南205和华南8号木薯苗在土壤干旱胁迫下的光合特性。结果表明：在正常供水、中度和重度干旱胁迫下,SC8叶片的最大净光合速率（Pmax）、表观量子效率（AQY）和光饱和点（LSP）均显著高于或不低于SC205,而光补偿点（LCP）2个品种之间无显著性差异。随着干旱胁迫程度的加重,Pmax、AQY和LSP呈现下降趋势,而LCP却升高;当光合有效辐射（PAR）为0~2 000μmol/（m2.s）时,随着PAR的增大,2个木薯品种叶片的净光合速率（Pn）、蒸腾速率（Tr）和气孔导度（Gs）均先迅速升高后趋向平缓,胞间CO2浓度（Ci）则迅速降低后也逐渐平缓,而水分利用率（WUE）却呈现先增高后降低的趋势;干旱胁迫下,气孔因素是引起木薯叶片净光合速率下降的主要原因。综上所述,干旱胁迫下木薯苗的光合特性受到限制,干旱胁迫下华南8号的光合特性和抗旱性要优于华南205。 The seedling photosynthetic characteristics of two cassava cultivars South China 205（SC205）and South China 8（SC8）under water stress were studied by pot experiment.Three water level treatments were designed：normal supply,mild stress and severe stress.The results showed that under water stress condition,the maximum net photosynthetic rate（Pmax）,apparent quantum yield（AQY）and light saturation point（LSP）of SC8 were significantly higher or not lower than that of SC205.The light compensation point（LCP）was not significantly different between the two species.With the severity of drought stress,Pmax,AQY,and LSP decreased,but LCP increased;When PAR was raised from 0 to 2 000 μmol/（m2.s）,net photosynthetic rate（Pn）,transpiration rate（Tr）and stomatal conductance（Gs）of the two cassava cultivar leaves increased rapidly at the beginning,then intercellular CO2（Ci） decreased rapidly,and consequently all of them changed gently.The water use efficiency（WUE）increased initially and then decreased,indicating that the decline of Pn was considered as a result of stomata restriction under water stress.In conclusion,the photosynthetic characteristics of the two cultivars were generally inhibited under water stress condition.The photosynthetic characteristics and drought resistance of SC8 were better than that of SC205 when water stress existing.

关 键 词： 木薯 干旱胁迫 光合特性

领　　域： [农业科学] [农业科学]