Histochemical Localization of Carbohydrate and Protein during Flower Bud Differentiation in Oncidium

The flower buds in different development stages of Oncidium 'milliongolds' were used as tested materials,and the changes of carbohydrate and protein during flower bud differentiation were studied by PAS method and histochemical coloration.The results showed that carbohydrate and protein mainly distributed in or around the apex of primordium.In inflorescence primordium differentiation phase,the content of carbohydrate was much less,while protein was richer and distributed uniformly.With the continued differentiation of the flower bud,carbohydrate and protein occurred abundantly in sepal primordium differentiation phase,and decreased obviously in petal primordium differentiation phase.The carbohydrate and protein focused on gynostemium and pollinia during gynostemium and pollinia differentiation phase.The contents of carbohydrate and protein in flower buds during Oncidium development process were determined,which showed that the change trends of carbohydrate and protein were consistent with the histochemical localization.