No abstract

SummaryPlants of Lolium temulentum L., a single.cycle, long.day plant, and Pharbitis nil Ohois. cv. Violet, a single·cycle, short-day plant, were subjected to osmotic stress during the inductive cycle. An osmotic potential of-IS atm (using poly. ethylene glycol, mol. wt. 4000) during the 24·hr exposure to light completely prevented flowering in L. temulentum. Similarly, -6 atm osmotic potential during the 16-hr dark cycle suppressed flowering in P. nil. Water stress during induction, achieved by withholding water to soil-grown plants, also prevented flower induction in Xanthium strumarium L.With L. temulentum and X. strumarium, stress accompanied by defoliation during the period immediately following the inductive cycle also prevented flowering. The data were consistent with a stress-imposed inhibition of translocation of the floral stimulus from the leaf. L. temulentum plants which were stressed but not defoliated during this period formed flowers, suggesting that the floral stimulus itself is relatively stable within the leaf during a period of stress.

Mandarin's SoE is national variety originated from Mount of Mutis