摘要
[Objective] The aim was to study adaptive evolution of the large subunits of RubisCO in Magnoliophyta crops. [Method] Taking Magnoliophyta crops such as corn and rice as research materials, the analysis on molecular adaptive evolution was carded out by using codon replacement and maximum likelihood methods. [ Result] The RubisCO suffered positive selection effect and six amino acid sites were identified. [ Conclusion] The six amino acid sites are of important guiding significance for studying catalytic activity of RubisCO large subunits and crop improvement.
分子进化中发生正选择的一个标志是密码子的错义替换（dN，氨基酸替代）比同义替换（dS，氨基酸不变）有更高的替换速率，计算dN与dS之比ω能衡量蛋白质的进化趋势和所受到进化压力的大小。ω=1、〈1和〉1分别说明蛋白质在进化过程中受到中性选择、负选择和正选择。
