Department of Botany, Faculty of Science, Kasetsart University, Nakhon Pathom 73140, Thailand.
*E-mail: narong77@hotrnail.com
Proceedings, 43rd Kasetsart University Annual Conference, Thailand, 1–4-February, 2005 Pp.180–187, (2005).
A study was conducted to evaluate the effects of cyanobacterial (Hapalosiphon fontinalis) extracts, obtained at the exponential (8 days) and stationary phases (16 days), on the germination of rice (Oryza sativa cv. Khao Dawk Mali 105), Chinese cabbage (Brassica campetris var. pekinensis [B. pekinensis]), wild pea (Phaseolus lathyroides [Macroptilium lathyroides]) and swollen finger grass (Chloris barbata) seeds. Results showed that the extracts inhibited the germination of all seeds. The stationary phase extracts were more effective than those obtained at the exponential phase, except on wild pea. The water extract was more effective than the methanolic extract. Cyanobacterial extract also significantly inhibited shoot and root growth of seedlings in a concentration-dependent manner. The allelochemical substances excreted from cells to the culture medium had no effect on seed germination and seedling growth of all species, except wild pea which only exhibited reduced shoot length.
