Gegensätzliche Wirkung der Sproßalterung auf die Blütenbildung bei Lemna paucicostata und Lemna gibba

Abstract

A Lemna frond generates new daughter fronds throughout its whole life span. Successively produced daughter fronds have different properties depending on the state of senescence of the mother frond at the time of daughter frond formation (s. W angermann 1965). Among the effects of mother frond senescence there is an influence on flower production in daughter fronds. In the short-day plant Lemna paucicostata 6746, the tendency for flowering increases the more the later the daughter fronds were produced. In the long-day plant Lemna gibba G1, on the other hand, a decrease of the flowering tendency is observed in daughter fronds with higher ordinal number. In Lemna , flower primordia are only produced on fronds at a very early stage of development. Therefore, mother frond senescence presumably influences the flower initiation in a direct manner. Whether a change in the hormone balance due to senescence is responsible for the alterations of floral evocation must await further testing.