Effect of Shading Levels and Soil Type on the Growth Characteristics in Potted Cultivation of Deutzia paniculata Nakai as an Endemic Plant Species in Korea
Deutzia paniculata Nakai(Hydrangeaceae) is a Korean endemic species with very restricted distribution in Gyeongsang-do, Korea. The plants with limited range of distribution are highly affected by various natural and artificial environmental disturbances resulting habitat loss and decline in population. The purpose of this study was to investigate the growth characteristics of D. paniculata based on the degree of germination in different soil types and shading under green house condition in Korea National Arboretum in the preparation to conserve from future extinction. Altogether seven soil types: native(control), forest soil, bed soil, peat moss, peat moss + perlite(2:1), peat moss + perlite + vermiculite(2:1:1), peat moss + perlite(3:1) with three replica each were used for the experiment. In each soil types the germination rate, survival rate, growth amount, leaf area, LMA(Leaf Mass per Area), SPAD value, and the amount of chlorophyll with the shading conditions(non-shading, 25% shading, and 50% shading) were measured. The result indicated that the highest germination(88%) was found in the bed soil. The survival rate was more than 90% in the non-shading and 25% shading conditions; however, it lowered to 10% in the 50% shading condition. The observation of plant height, leaf number, leaf length and width of seedling in bed soil showed the highest growth was in non-shading treatment, and the lowest growth was in soil 50% shading treatment. The chlorophyll content of each treatment in bed soil with non-shading treatment was 1.64(a=0.77, b=0.87) whereas it was 1.54(a=0.69, b=0.84) in 25% shading treatment. The average LMA for each treatment was 0.45(mg/cm2). We found the strong negative correlation between the shading levels and the number of leaves, leaf width, leaf length, leaf area, plant height and SPAD. Overall result indicated that D. paniculata greatly favored bed soil and non-shading condition in the greenhouse. Through this study we have established a series of processes regarding the appropriate degree of soil and shading conditions for growth and germination of D. paniculata. Thus, these processes can be applied in various research fields for preservation and proliferation of the species.