详细解释:n. 光周期
词型变化：
形容词:photoperiodic详细解释：
pho.to.pe.ri.od
n.（名词）The duration of an organism`s daily exposure to light, considered especially with regard to the effect of the exposure on growth and development.光周期：有机物每天暴露于阳光的时间，着重考虑的是暴露于阳光对生长和发展的影响
【引伸】
pho.tope.riod.ic