Studies On The Flowering Reversion Of Soybean Plant

The phenomena of flower reversion, inflorescence reversion and whole-plant reversion were observed and could be induced under suitable photoperiod treatments in Zigongdongdou, a late maturing soybean variety from Sichuan Province, China. After emergence, the seedlings were treated with I 2h short day (SD) for about 10 days. During the SD treatment, all the trifoliolate leaves were taken off as soon as they appeared. Then, the plants were transferred to a long day (LD, >1 5h) condition. Under the treatment, it was found that the plants initiated flower primordia and then formed a terminal inflorescence, but the upper part of the inflorescence was reversed to vegetative structure. The normal flowers, reversed flowers (with one bract and two bracteoles but without floral organs) and normal vegetative buds could be seen on the same inflorescence. In another situation, when the normally flowering plants at Ri to R3 were transferred and treated under LD (>1 5h), the existed flowers and young pods dropped down, new branches appeared and the whole plant reversed to vegetative growth. This phenomenon was designated as whole-plant reversion. The reversed æ…ºlowers?could be found on the newly formed branches occasionally and the reversed plants could bloom again and mature if transferred to SD for enough days. Flowering reversion could also be induced through night break with red light (R) and its effect could be reversed with far-red (Fr) light exposure. Flower reversion and inflorescence reversion were found on the plants treated with 1 2h SD for 13 days after emergence and then treated under 1 4h SD with night break of red light (R), Fr-R or R-Fr-R. The whole-plant reversion could be induced with above night break after flowering, too. Photo-thermal interaction was evident in induction of flowering reversion of soybeans. The LD inhibiting effect on flowering was stronger under a higher temperature than under a lower one. The flowering reversion is a newly found phenomenon and might be of importance in studying the ontogeny and development of soybean. Wu Cunxiang, Master Candidate in Crop Physiology Supervised by Prof Han Tianfu...