在弹性光网络中，光树传输组播可以节省链路代价，但较长的光树需要选择更低的调制等级，消耗更多的频谱资源和发射机功耗。提出一种基于遗传算法的光森林组播和光树重配置(GAMF-TR)优化组播的能效路由、调制格式和频谱分配(RMSA)策略。GAMF-TR策略设计染色体编码表示光森林的组播目的节点划分和光路径组合，通过染色体的基因位概率交叉和变异得到更多的光森林RMSA策略，设计了一个频谱分配效率和发射机功耗折中的适应度函数选择能效最高的光森林RMSA策略，并设计在网络资源充足时将组播从光森林重配置到光树传输，进一步减少发射机功耗的消耗。仿真结果表明: 提出的GAMF-TR策略获得了组播的最低带宽阻塞率和最高能效性能。

In elastic optical networks (EON), light tree is usually used to transmit multicast for its low transmission cost. But the longer tree has to adopt the lower level of signal modulation which consumes more spectrum resource and transmitter power. In this paper, a strategy of genetic algorithm-based multicast forest with tree reconfiguration (GAMF-TR) is proposed to optimize the multicast routing, modulation format and spectrum allocation (RMSA). In GAMF-TR strategy, the encoded chromosome represents the destinations partition and each lightpath between source and a destination. By the probability crossover and mutation operation of gene, more forecasts RMSA scheme can be achieved. A fitness function considering the tradeoff between the spectrum allocation efficiency and optical transmitter power is designed to select the energy-efficient forecast RMSA scheme. And when there is enough spectrum source in the optical network, the optimized forecast can be reconfigured to a tree for transmitting the multicast with lower transmitter power. The simulation results show that the proposed GAMF-TR method can get the lowest bandwidth blocking probability and the highest energy-efficient performance for the multicast.