Effect of Temperature on Seed Germination of Korean Native Viola Species

Present studieswere performed to determine the physiology of seed germination in Viola species native toKorea. Twelve species, 1 variety and 1 formwere collected, classified and used asmaterials: V. collina, V. blandaefomis, V. rosii, V. chaerophylloides, V. phalacrocarpa, V. patrinii, V. mandshurica, V. mandshurica for. albescence, V. seoulensis, V. yedoensis, V. keiskei, V. variegata, V. variegata var. chinensis, and V. verecunda. V. tricolor 'HelenMount' was also used to compare wild with cultivated species. In order to investigate the effect of temperature on seed germination, seeds stored at 4±2℃ for 10months or 4 yearswere incubated at 10, 15, 20, 25℃ under 16h illuminationwith 4 replicates per treatment. Seeds which had not germinated at 10℃ were transferred to 30℃ to assess the effect of temperature change in germination. Germination percent and the days of first, 40% and 80% germination were assessed. Capability of seed germination variedwith taxon; Species belonging to subsection Patellares had high ability of germination, compared to species in the other subsections, and series Chinensiswas the best among subsection Patellares. Species capable of high germination germinated in all temperatureswith reasonably high germination rate, but the other species responded sensitively to temperature with different germination patterns. Higher the temperature, shorter the incubation time required for first, 40% and 80% of germination. Therefore, high temperature was effective in almost all species, not only for inducing high rate of germination but also the uniformity of germination. Temperature change from10℃ to 30℃ had a positive effect on seed germination.