Researched on morphological differentiation of flower bud in early stage of red flesh navel orange

Paraffin cut method was used to observe the developing process of the flower bud differentiation of red flesh navel orange. The results showed that the flower bud differentiation initiated from early November,the sepal began to differentiate in late November;it came into petal differentiation stage in middle-January of the next year,after that,the stamen and pistil differentiation stage began in late February;each of these stages lasted for a relative long time. The process could be divided into seven phases:the bud before flower initiation,flower bud differentiation stage,sepal differentiation stage,petal differentiation stage,stamen differentiation stage,pistil differentiation stage,ovary differentiation stage. It had large number of flowers,the developing process of the flower bud differentiation of red flesh navel orange were relatively slow,distract and long,each stage had overlap layering effect.