研究了甘蔗Ｆｌ代１０个家系单叶净光合速率（Ｐｎ）的遗传趋势。结果表明，Ｐ。的表型分布近似正态分布，属于数量性状遗传，受微效多基因控制。广义遗传力（ｈ８较低，为２１．５８ｏｐ～３０．６８ｄｅ，因此，在低世代对Ｐｎ的选择应适当降低选择强度并根据与Ｐｎ密切相关 The genetic tendency of net photosynthetic rate (Pn) of single leaf in 10 F1 lines of sugarcane was studied. The results show that P The distribution of the phenotype is approximately normal distribution, which belongs to the quantitative trait inheritance and is under the control of the micropowder polygene. The general heritability (h8 is low, 21.58op ~ 30.68de, therefore, the choice of Pn in lower generations should be appropriate to reduce the selection intensity and is closely related to Pn