|
Bioactivity of Ulva
lactuca
L.
acetone extract
on germination and
growth of lettuce and tomato plants
S. M. Hassan* and H. R. Ghareib
Department
of Botany, Faculty of Science, Beni-Suef University, Salah
Salm Street, Beni-Suef, Egypt.
*Corresponding author. E-mail:
abood127@yahoo.com.
Accepted 19
June, 2009 |
|
Ethanol, butanol and acetone extracts of Ulva lactuca
L. (Chlorophyta)
at concentrations 10, 30, 100 and 300 ppm for each were
applied to determine their biological activity under
laboratory conditions using etiolated wheat's coleoptile
growth bioassay. Acetone extract was the most active one and
was selected to investigate the allelopathic potential on
lettuce and tomato's seed germination and seedling growth.
Nine free phenolic compounds were detected in the Ulva
acetone extract by using HPLC analysis. Vanillin and
p-
coumaric acid
was
recorded as the abundant compounds while ferulic acid and
salicylic acid existed in less amounts. Compared with the
control, the germination of lettuce and tomato were
stimulated by 5.8 and 21.5%, respectively, when treated with
low concentration of acetone (30 ppm). In contrast, high
concentration (300 ppm) retarded the germination and
recorded high inhibition effect on lettuce (44.6%). Acetone
extract, at 30 ppm, stimulated the radicle and plumule
growth of lettuce by 10.6 and 27%, respectively, and tomato
by 22.5 and 35%, respectively. Meanwhile, at 300 ppm,
radicle and plumule growth of lettuce was greatly inhibited
by 40.6 and 30%, respectively, whereas tomato was slightly
inhibited. Moreover, roots appeared more sensitive to
allelopathic effect than shoots.
Key
words:
Ulva lactuca, allelopathy, phenolic compounds, wheat
coleoptile, lettuce, tomato. |
