Research Article

Seed Dormancy Breaking, Germination and Salt Stress Response of the Highly Invasive Cordgrass (Spartinaspp.)

Jin-Seog Kim^1,* Bo Gwan 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, several biological characteristics were investigated with seeds (caryopses) and rhizome of a highly invasive cordgrass (Spartinaspp.). Seed set proportions of both S. alterniflora (SPAAL) and S. angulata (SPAAN) were 80 to 85%. The most effective treatments for dormancy breaking of dried seeds (caryopses) were to soak them in freshwater or seawater of 0.5% salinity and to store for more than 100d at 4℃. The germination percentage of dormancy-released seeds was 80-90% and 60% in SPAAL and SPAAN, respectively. They were able to be germinated in the dark and also in the high temp. regime (35℃ light/25℃ dark). Incubation time required to complete the germination of SPAAL seeds was 5 to 30d, being defferent according to a dormancy degree. Secondary seed dormancy by re-drying was not observed. In the test of salt stress, germination percentage of SPAAL was 91% in freshwater and 40% in seawater of 6% salinity, decreased with increased salinity. When the ungerminated seeds in the salty solution were transferred to tap water, many of them did re-germinate. Growth of SPAAN rhizome segments was better in upland condition than in flooding upto the soil surface and not markedly reduced by 4% salinity, but were completely inhibited at 6% salinity. Based on these results, to establish the integrated strategies for a improving management of cordgrass, it is recommended that seed dispersal as well as axesual reproduction through rhizomes, and possibility occurring in terrestrial land in addition to seashore or saline marsh should be considered together.

Figures & Tables

Fig. 1.Size and weight distribution of (SPAAL) and S. angulata (SPAAN) seeds collected in Jindo and Gangwhado, Korea.