Abstract: | The interrelationships between simultaneously developing organsof citrus flowers were investigated. Examination of flower organgrowth kinetics shows that petals grow mainly through enhancedwater absorption whereas ovaries accumulate a high percentageof dry matter. Using excised flowers implanted in an agarsucrose mediumand supplied with 14C]-sucrose, 3H]-acetate, and 14C]-acetate,a characteristic distribution of label among organs could beestablished for each isotope. Wounding or application of -naphthaleneacetic acid (NAA) toa single petal completely changed the normal distribution patterns,shifting the bulk of 14C]-sucrose towards the treated organs. The findings are interpreted in the light of the sinkhypothesis. It is proposed that each flower organ meristem createsa sink of its own which acts in a typical manner according toits specific endogenous hormonal balance. The sink activityof all meristems in concert results in a sensitive regulatorymechanism which is responsible for the coordination observedin flower development. |