不同类型烟草苗期生长和光合特性研究

试验以烤烟、晒烟、白肋烟3个不同类型的11个品种为材料,在相同条件下,采用漂浮育苗方式,对苗期的生育进程,第4片真叶的生长状况、SPAD值、光合特性,以及成苗期的生物学性状进行了研究。结果表明:晒烟品种在苗期的生育期较短,第4片真叶长度最大,烤烟品种第4片真叶宽度最大;烟草不同类型之间的光合特性差异较小,而不同品种之间的光合特性差异较大,净光合速率与胞间CO2浓度、蒸腾速率、气孔导度之间相关性显著;烟苗鲜重根冠比表现为:白肋烟>烤烟>晒烟,干重根冠比表现为:白肋烟>晒烟>烤烟,总干鲜重比表现为:白肋烟>烤烟>晒烟。

Studies on Seedling Growth and Photosynthetic Characteristics of Different Tobacco Types

The experiments with 11 varieties of three types tobacco(flue-cured tobacco,sun-cured tobacco and burly tobacco) were carried out by floating system under the same condition to study the seedling growth period,the fourth leaf growth condition,SPAD value,photosynthetic characteristics,and the plant biological characteristics of transplanting period.The results showed that the seedling growth stage of sun-cured tobacco was shorter than that of the other two types,and its fourth leaf length was the largest among the three types tobacco,while the flue-cured tobacco's fourth leaf width was the biggest.The differences of the photosynthetic characteristics were small among three types tobacco while there were big differences among varieties.The net photosynthetic rate was significantly correlated to the intercellular CO2 concentration,transpiration rate,and stomatal conductance.The fresh root-shoot weight ratio of different types tobacco seedlings showed burley tobacco > sun-cured tobacco > flue-cured tobacco,while the dry root-shoot weight ratio of seedlings presented burley tobacco > sun-cured tobacco > flue-cured tobacco.The ratio of dry weight to fresh weight of tobacco seedlings displayed burley tobacco > flue-cured tobacco > sun-cured tobacco.