Flower and Pod Shedding in Soybean Plants with Special Reference to Raceme Order.

Abstract

This study was conducted to investigate the characteristics in terms of the identification of the raceme order (RO) for flower and pod shedding in soybean plants (c.v. Tatisuzunari). The control plot was provided as the reference using the Wagner pots (1/2000 a) independently, whereas the shading treatment was made specifically during flowering period. In the control plot, the percentage of the shedding buds, flowers and pods reached 5, 28 and 66% respectively. It can be observed that the total amount of shedding tended to increase due to the shading of light, particularly so for the flower shedding. The flowering takes place in the short duration of 20 days after the initiation stage ; however, the shedding lasts for a fairly long period, ranging from the stage shortly after flowering initiation to the ripening stage. The flowering of the raceme starts orderly from the lower RO including zero-and 1st-order, and then extends toward higher RO. This flowering order can be recognized in the similar manner for the shedding, and each RO showed continuous shedding up to the ripening stage. The following five stages are able to describe the inherent transition of RO :Stage-1, flower shedding in lower RO ;Stage-2, flower shedding in higher RO ;Stage-3, pod shedding in lower RO together with flower shedding in higher RO ;Stage-4, pod shedding in higher RO together with flower shedding in higher RO and pod shedding in lower RO ;Stage-5, pod shedding in lower and higher ROs.