Effect of Seed Collection Stage and Temperature on Germination of Deutzia paniculata Nakai, the Korea Native Species

In this study, we investigated the effect of seed collection stage and alternating temperature on the germination of Deutzia paniculata (Hydrangeaceae). The seeds were collected from naturally growing D. paniculata populations in Mt. Palgong, Gyeonsangbuk-do, Korea every two weeks over a three month period from August through October, 2014, totaling five collections. We examined seed characteristics such as seed size (length and width) and weight, and germination percentages for each collection stage under four different germination temperature regimes. We also examined germination after 30 and 60 days of cold moist stratification. Each collection phase had a different germination percentage and the lowest germination percentage was observed in the seeds from phase I (average GP of 15.7%). The germination percentage was similar at the later collection phases and in the higher temperatures suggesting that later collection times and higher temperatures are optimal for D. paniculata germination. We found that the optimum collection stage with high viability and germination percentage of for D. paniculata was during the middle of the September.