榨菜花芽分化早期形态发育及细胞超微结构初探

根据光学显微镜和透射电镜的观察，按榨菜(Brassica juncea Coss.var Tumida Tsen et Lee)在二叶期后进行不间断光照诱导288 h期间的茎端生长锥形态特征，将榨菜花芽分化初期形态发育过程分为5期：花芽未分化期,未诱导；花原基将分化期,诱导72 h，2片真叶充分开展；花原基分化始期,诱导144 h，第3片真叶充分开展；花原基增大伸长期,诱导216 h，第4片真叶充分开展；萼片形成期,诱导288 h，第5片真叶开展。不同成熟期品种间花芽发育速度为早熟>中熟>晚熟。在这期间茎端细胞内核仁、线粒体、叶绿体等的形态、大小、数量、发育程度等发生明显变化。植株由营养生长转入生殖生长时，茎端细胞的核内有2个或多个核仁。

Study on the morphological development and cellular ultrastructure of early stage of differentiation of floral bud in tuber mustard (Brassica juncea Coss.var tumida Tsen et Lee) .

Based on the morphological characteristics of vegetative cone in stem apex at the end of two leaf stage seedlings of tuber mustard which was observed by optical microscope and transmission electron microscope,during the 288 h continuous light treatment,the process of early stage of floral bud differentiation was divided into 5 stages:Non differentiation stage which the seedlings was uninduced by light; The would be differentiating stage of floral primodium,after 72 h light treatment which the second leaf was fully expanded;The initial differentiation stage, after 144 h treatment when the third leaf was fully expanded;The elongating and expanding stage after 216 h treatment when the forth leaf was fully expanded;The sepal forming stage, after 288 h treatment when the fifth leaf was fully expanded.The development of floral bud in early mature variety was earlier than late ones. The significant changes were obseved in the morphology,size,number and the degree of development of nuclei,nucleole,mitochondrial and chloroplast of apicalmeristem cell.There were two or more nucleole in the nuclei of the apicalmeristem cell when the plant went into reproductive phase from vegetative phase.