Research Articles : Identification of Initiation Period and Subsequent Development of Floral Primordia in Black Locust (Robinia pseudoacacia L.) = Research Articles : Identification of Initiation Period and Subsequent Development of Floral Primordia in Black Locust (Robinia pseudoacacia L.)

다국어 초록 (Multilingual Abstract)

The objectives of this study were to identify the period of initiation of floral primordia in black locust (Robinia pseucloacacia L.) and subsequent development of floral buds until following spring. Four mature trees of black locust located in Suwon, Korea were selected. Bud samples were collected from the current-year shoots, starting from mid June to July every week, from August to October and from February to April every month. The buds were fixed in FAA solution, dehydrated, and imbedded in paraffin for microscopic observation. Buds collected on June 16, and 23, 1997, contained primitive primordia that might be interpreted as early floral primordia. By June 30, a bud showed a positive indication of inflorescence primordiurn with a well-formed shoot apex. All the inflorescence primordia observed throughout the collection periods were always associated with unique hairy appendages around the primordium and enclosed within a sclerenchymatous chamber. By July 7 and 15, a floral apex had early bud scales. By July 22. primitive inflorescence developed into visible arrangement of individual floral primordial By July 29, the inflorescence developed into whirl arrangement of individual floral primordia in a transverse section, but showed little further development until October 15. The inflorescence primordia seemed to over-winter at this stage. Buds collected from February 15 and March 24 the following year also showed no further development of inflorescence primordia. By April 7 the inflorescence started to show farther development with elongated axis. At this time individual flowers were easily recognized.