The clonal dependence of turion formation in the duckweed Spirodela polyrhiza--an ecogeographical approach.

Formation of turions, the vegetative perennation organs, plays an important role in the survival strategy of Spirodela polyrhiza (L.) Schleiden. Turion formation [quantified as number of turions formed per frond; specific turion yield (SY)] was investigated in 27 clones collected from a wide geographical range.