SEEDS OF ELEPHANT APPLE (DILLENIA INDICA L.) RESPONSE TO SOME PRE-GERMINATION TREATMENTS

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.