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Sulfuric acid and hot water treatments
enhance ex vitro and in vitro germination of
Hibiscus seed
Hamidou F. Sakhanokho
USDA-ARS, Thad Cochran
Southern Horticultural Laboratory, P. O. Box 287, 810 High
Way 26 West, Poplarville, MS 39470.
E-mail:
Hamidou.Sakhanokho@ars.usda.gov.
Accepted 24 August, 2009 |
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Seeds of
Hibiscus
dasycalyx S. F. Blake and Shiller, a federally listed
candidate endangered species and native to North America and
two variants of Hibiscus acetosella Welw. ex.
Hiern were scarified using sulfuric acid and hot water. The
effects of the scarification methods on in vitro and
ex vitro germination in both species were evaluated.
Sulfuric acid scarification was very effective for in
vitro and ex vitro germination of both
forms of H. acetosella and H. dasycalyx
seeds by dramatically increasing germination rate and
decreasing germination time. Acid scarification of H.
acetosella seeds for 10, 15, or 20 min resulted in
close to 90% germination within a week. Germination rates of
about 70% (ex vitro) and 80% (in vitro)
were obtained in H. dasycalyx seeds treated
with sulfuric acid. Germination rates of 54% (ex
vitro) and 95% (in vitro) were achieved when
H. dasycalyx seeds were treated with hot water
for 5 min, but exposing the seeds for 10, 15, or 20 min
produced poor results in H. acetosella and H.
dasycalyx as hot water scarification appeared to
result in severe injury or death of the embryos. The
protocols described here constitute rapid, reliable and
simple methods to germinate H. acetosella and
H. dasycalyx seeds in vitro and ex
vitro. These results can be valuable in commercial
productions or research projects. In addition, the in
vitro germination of H. dasycalyx can
offer a valuable tool in conservation efforts for this
threatened species.
Key word:
Hibiscus dasycaly,
Hibiscus acetosella, seed scarification, in vitro
seed germination, ex vitro seed germination. |
