This experiment was consummated under shade at the
nursery of Hort. Res. Inst., ARC, Giza, Egypt during 2013 and 2014
seasons to explore the effect of some pre-sowing treatments, viz.
control (untreated seeds), seeds without mucilage, soaking in tap water
for 24, 48, 72 h under ambient conditions, soaking in hot water (60-
70C) for 24h, soaking in absolute ethanol (97%) for either 12 or 24 h
and soaking in concentrated sulfuric acid (98.5%) for 3 min on
germination measurements of Elephant apple (Dillenia indica L.) seeds
and growth of the produced seedlings.
The obtained results have shown that seeds of control and those
soaked in either hot water or ethanol for 24 h failed to germinate, while
seeds without mucilage and those soaked in ethanol for 12 h gave the
least germination percentage in the two seasons. The other treatments,
however significantly improved germination %, with the superiority of
soaking in concentrated H2SO4 for 3 min treatment, which elevated
such parameter to 100% in both seasons. Besides, germination % was
found to progressively increase with elongating soaking period in tap
water to reach 100% in the first season and 83.33% in the second one
by the longest soaking period (72 h). The germination velocity and
mean germination rate were accelerated and the indices of germination
rate and vigour, seeds viability and plumule length were significantly
improved by some treatments used in this trial, but the prevalence was
also for acid treatment which followed by soaking in tap water for 72 h
treatment. Similarly, were those result of seedling growth traits and
leaf content of chlorophyll a, b, carotenoids, total soluble sugars,
indoles and phenols, as the soaking in concentrated H2SO4 for 3 min
treatment scored the best growth of the seedling and the highest
content of the various constituents which was accompanied with the
least content of total phenols. Also, soaking in tap water for 72 h
occupied second rank.
So, it advised to soak Elephant apple (Dillenia indica L.) tree seeds
either in concentrated sulfuric acid (98.5%) for 3 min or in tap water
for 72 h to obtain the best germination and quality of seedlings.