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The germination of korarima (Aframomum
corrorima (Braun) P.C.M. Jansen) seeds faces certain problems. The
study was carried out to explore the effects of different seed
treatments on germination and seedling growth attributes of korarima.
Seeds were
subjected to seven pre-sowing treatments viz.,
control (no pretreatment)
(T0), soaking in tap water for 24 h (T1), soaking in 50% sulfuric
acid (H2SO4) for 60 min (T2), soaking
in 50% sulfuric acid (H2SO4) for 60 min, followed
by soaking in 250 mgL-1 gibberellic acid (GA3)
for 24 h (T3), cold stratification at 4±1oC
for one week (T4), cold stratification at 4±1oC
for two weeks (T5) and cold stratification at 4±1oC
for three weeks (T6). Also micropropagation systems were
developed for highland korarima cultivars viz., Mume, Wondogenet and
Mesketo. The effective concentration of hormones for shoot
multiplication and rooting in cultivar Mume were determined. Two explant
sources, in vitro seedling shoot tips and field grown rhizome buds of
cultivar Mume were evaluated. The study revealed that exposure of seeds
to T3 was the most effective treatment for enhancing
germination (88.3%), followed by 81.7% germination obtained from T2
after 6 weeks of sowing. Other treatments were less effective. Seed
pretreatment had positive effects on seedling height, number of leaves,
root number, root length and fresh weight. The highest number of shoots
and percent survival was achieved in the cultivar Mume as compared to
other two cultivars after five weeks of in vitro culture. Significantly
higher shoots number (11.00), leaves number (15.33) and fresh weight
(0.81 g) per explant of cultivar Mume was obtained when cultured on
Murashige and Skoog (MS) medium containing 0.5 mgL-1
thidiazuron (TDZ) compared to number of shoots (2.67), number of leaves
(6.00) and fresh weight (0.25g) in the control. MS medium with 0.5 mgL-1
TDZ and 3 mgL-1 6-benzyladenine (BA) also gave high shoot
number (10.00) per explant. The growth parameters were significantly
correlated. The highest percent survival and number of shoots were
obtained from in vitro seedling shoot tips compared to rhizome buds. The
indolebutyric acid (IBA) at 1 mgL-1 significantly promoted
the rooting (75.56%) over the control (33.33%).
Key words:
Aframomum corrorima,
korarima, cultivar, seed germination, seedling growth, micropropagation,
shoot formation. |
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