Germination and Growth Characteristics of Giant Duckweed (Spirodela polyrhiza) Turion

Bo Gwan Kim1   Jin-Seog Kim1,*   

1Research Center for Eco-Friendly New Materials, Bio & Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea

Abstract

In this study, dormancy, germination and initial seedling growth characteristics of giant duckweed (Spirodela polyrhiza L., SPIPO) turions were investigated to use them as a bioassay materials for new herbicidal compounds. Freshwater storage of more than forty days at 4℃ was required to break down the dormancy of SPIPO turions. The turions were highly sensitive to dryness. The dormancy-broken turions did not germinate under the dark condition at all. However, the dark storage treatment of turions at room temp during 2-3 d shortened germination by one day compared to untreated ones. The germination percentage and velocity of SPIPO turions had a tendency to be increased when they were incubated in tab water or 1x mDM medium than in distilled water. The optimum temperature for germination of SPIPO turions was 30℃ in distilled water, but 35℃ in tab water or 1x mDM medium. On the other hand, the initial growth of the generated fronds was favorable at 30℃ in even 1x mDM solution interestingly. Taken together, it is recommended that the turions which had been soaked in tab water or 1x mDM solution during more than 60 d at 4℃ are useful as a materials for herbicidal bioassay and that the bioassay is carried out at around 30℃ and light condition.

Figures & Tables

Fig. 1. Effects of storage temperature and duration on the germination to turions. A: Germination at 3d after incubation, B: Germination at 10d after incubation.