EFFECT OF PLANT-DENSITY AND MACRONUTRIENT NUTRITION ON DELPHINIUM SHOOT CULTURES

The effect of shoot density on the uptake of macronutrients from MS medium and growth rates of Delphinium shoot tissue cultures was determined, Multiplication rates and uptake of phosphate, nitrate and sugar per shoot increased with decreasing shoot density. Increasing the concentration of total nutrients significantly increased both fresh weight gain and multiplication rate at the high plant density (15 shoots 50 ml-1 medium) usually used for micropropagation. However, increasing the phosphate concentration (phosphate being the nutrient most rapidly depleted in the medium) resulted in higher fresh weight only, while the multiplication rates of shoots remained similar.