树莓花芽分化的观察

1991～1992年,对树莓花芽分化时期的形态特征及发育进程进行了定期观察。结果表明,树莓花芽分化始期为8月末,9月中下旬进入高峰期,约60～70d。形态特征是雏梢生长点向上隆起成半球状。10月上旬至翌年4月中旬,随初生髓部的伸展,半球状生长点(顶花序原基)向前推进,随后形成腋花序原基,即为花序原基分化期。随同冬芽萌发展叶,依次进入花蕾、萼片、花瓣、雄、雌蕊原基的芽外分化阶段,各期约7～15d。至5月中旬出现花药和胚珠原始体。此期距结果新梢的花序显露还有2～3d。基生枝下部花芽分化始期比中上部迟一个月,分化数量也有较大下降。

Research on Flower Bud Differentiation in Raspberry

Morphological characteristics and developmental process of flower bud differentiaton in raspberry were observed every 5 to 7days in 1991 and 1992. The results were as follows : Flower bud differentiation started in late August,which might last for 60 to 90 days, and climaxed in mid-September. At this time, the morphological characteristics showed that the growing points of the shoots presented prominent semi-spherical shape. From early October to next mid-April, along with the expansion of primary pith tissue, semisphere-shaped growing points (terminal inflores-cence primordia) continued to develop and formed axillary inflorescence primordia. That was the stage of inflorescence primordium differentiation. When the dormant buds started to sprout, flow-er primordia were formed, and floral parts differentiated aeropetally with sepal primordia appear-ing first, followed by petal, stamen and pistil primordia, respectively. Anther and ovule were formed in mid-May. 2 to 3 days later, the inflorescence of bearing shoots would appear. Buds in the lower portions of primocanes differentiated a month later than in the middle and upper por-tions, and the number of differentiational flower buds decreased to a large extent.