Pre-Treatment of Seven Acacia spp. Seeds to Improve their Germination Responses.

Abstract

Acacia species arc considered as promising trees for afforestation and fodder with high relative palatability and nutritive value in and semi-d-arid regions. Seeds of many acacia species do not or slowly germinate for their thick, hard, bony, or wax covered seed coats. The objective of this study was to define the optimum treatment of different Acacia species seeds to have germination occur quickly and uniformly. Six methods (including control ) of seeds pre-treatment for seven Acacia species were investigated. These treatments were soaking seeds in concentrated sulfuric acid for 2 and 6 hours, in hot and boiled water for 24 hours, cold stratification and control. Seed germination % were recorded for fifty days, under controlled greenhouse, in three different dates represent Autumn, winter and spring. Acacia species under study were Acacia salicina, A. victoria. A. sclerospenna, A. inguilatera. A. nilotica. A. cuthberisonii and A. pruinocarpa . Results revealed that, seeds without pre-treatment (control) and with cold stratification pre-treatment for all species had low germination % (less than 12 % except A. nilotica which revealed about 30%). Seeds of species (A. victoria, A. sclerosperma, A. cuthbertsonii and A. pruinocarpa) pre-treated with sulfuric acid (2 hr or 6 hr) germinated with high significant percentage than that pre-treated with water (warm or boiled water). These species had relatively hard seed coat. Most of non-germinated seeds treated with water or acid may be geminate after the breakdown of dormancy. The seeds of species (A. salicina - A. nilotica) pre-treated with acid and germinated with low significant percentage than that pre-treated with water had relatively soil seed coat , and most of non-germinated seeds treated with water may be germinate after the experiment period , but seeds pre-treated with acid will not germinate . This was due to penetration of acid into the endosperm and embryo, damaging them and kill the seeds completely