Author : Chanthol Sao

Summary : Good physiological quality of seed such as high germination percentage and vigor are the most important factors to be considered in the production of high quality tree seeds for commercial plantations. This study therefore was undertaken with the main objective of enhancing the germination and storage condition of commercially important tree seeds, Dyera costulata Hook.f. and Macaranga gigantea Mull. this study also envisioned of developing tetrazolium test for rapid detection of seed viability. several germination media such as paper, sand, soil, forest soil, coconut husk and paddy husk were tested for best germination. Whereas, three different storage conditions (refrigerated i.e. 10 and 20°C and ambient i.e. 30°C) and different storage periods (0, 31, 89 and 181 days); three different plant growth hormones (GA3, BAP and kinetin) at four different concentrations (0.1,0.2,0.5 and 10 mg/l) were used to determine the best conditions for storage and growth promoter for both D. costulata and M. gigantea seeds. In addition, three different germination media (sand, soil and forest soil) and light regimes (25%,55% and 75% relative light intensity) were tested to find out the best condition for seedlings growth. The results of the study indicated that the best germination media for both tree seeds was the sand, followed by forest soil and soil. this study also revealed that the best temperature for storage was at 20°C giving from 85 to 97% seed viability. However, storage of more than 89 days tends to reduce the germination rate when stored at 10°C, and 20°C and more 30 days if stored at 30°C. Meanwhile, among the three tyoes of hormones it was found that GA3 at 10mg/l was most effective not only on the germination but also on excised seedcoat. While, among the concentrations used 10 mg/l gave an overall best result for all the hormones in enhancing the germination process. On the other hand, it was found that seedlings grow best when planted in forest-soil.