Morphological and Anatomical Change on Apical Development in Soybean

Abstract

A study on apical development of soybean varieties NS1, CM 60, Leichhart and CPAC 98-76 was undertaken. Plants were grown in pots on June 1, and November 25, 1997 at the Department of Botany. For morphological study of the apex, floral initiation (R₀ stage) and floral development (R₀ - R₁ stage) were illustrated for each variety. Floral initiation was identified by using apical dissection technique at 40X magnification. The results indicated that there were greatly differences in the duration of floral initiation among the varieties and sowing dates ranging from 14-32 days after sowing. NS 1 was notified that having a short juvenile phase whereas Leichhart was having a long juvenile phase. By contrast, the floral development phase was not influenced by sowing dates, though, markedly differences between varieties was detected. Developmental anatomy of terminal bud during the formation of floral bud showed that apical dome shape containing 2 layers of the well organized cells tunica, and the other, unorganized cells of 3-layer corpus emerging between the 2 prophyll. The formation of florets along the inflorescence was notified to be upward by which the second floret developed faster than the first floret. In the floret, sepal and petal primordia initiated, thereafter, the apical of floret would be flatted coincidentally with the development of stamen. Petal primordia developed slowly and were soon surpassed in growth by the stamens.