Studies On The Post-Flowering Photoperiodic Responses In Different Ecotypes Of Soybeans

Typical varieties from the main ecological regions and Maturity Groups in China were chosen to study the post-flowering (Rl) photoperiodic responses among soybeans. The results indicated that the response to post-flowering photoperiod existed among the varieties belonging to the different Maturity Groups. The respose was not caused by the effects of temperature, photosynthetic duration or pre-flowering photoperiodic after-effect but was typical photoperiodism. The response was not only at the stage of Rl to R5 but also at the stage from R5 to R8. Upon the former and present results, a hypothesis of Pan-Photoperiodism was proposed. According to this hypothesis, the photoperiodic demand for flowering and fruiting in crops was considered to be a continuous process. The regulation of photoperiod to developmental proceeding was held from emergence to maturity. There were some common basis in photoperiodic effects on the flowering induction and maturing hastening. The photoperiodic effects had after-effect and were reversible.