The Effect of Environmental Factors on Growth, Development and Alkaloid Production of Poppy (Papaver somniferum L.): II. Interaction of Light and Temperature

Summary Optimum growth of Papaver somniferum cultivars of different origin was observed at 1.6 · 10 4 lux light intensity under “low temperature” programme (daily rhythm of 12.5/7.5 °C increasing to 18.5/11.5 °C during the vegetation). The maximum of dry matter was also produced in a “low temperature” programme, but at a higher light intensity of 3.2 · 10 4 lux. At the same time low temperature hindered the development by 10-15 days and modified the ratio of organs: proportion of leaves increased, that of the stems diminished. The alkaloid accumulation in dry capsules was determined by external conditions followed the generative differentiation of apex. The total amount of alkaloids (morphinane + phthalideisoquinoline + benzylisoquinoline) reached a maximum value in a “high temperature” programme under the 3.2 · 10 4 lux illumination (18.31 mg/g). Under the same illumination level the accumulation was limited by the cold effect. Inside the morphinanes, the ratio of codeine was decreased below 10 %, even in individuals have been evaluated as a codeine-type. Thereby, the importance of light-temperature interaction in the de methylation processes of poppy alkaloids has been proved.