The effect of environmental factors on growth. Development and alkaloid production of poppy (Papaver somniferum L.). I. Responses to day-length and light intensity
Bernath, J.; Tetenyi, P.
Biochemie und Physiologie der Pflanzen 174(5/6): 468-478
Short-day rhythm hindered the stem growth (by 45-60%), the flower initiation (by 3-45 days), and the alkaloid accumulation (by 4-5 times in some cases) of Papaver somniferum in comparison with long-day program. Under long photoperiods increase of the light intensity (from 0.8 × 10^4 lux to 3.2 × 10^4 lux) accelerated growth and development of the three cultivars investigated: optimum growth occurs at IM 10^4 lux, whereas optimum development was observed at 3.2 × 10^4 lux. Similarly, the alkaloid biosynthesis increases 2-3 times at higher light intensity of long-day treatments (2,4-3.2 × 10^4 lux). At the same time the proportion of the higher methylated alkaloid components rises. In the ease of certain cultivars, depending on light condition, the presence either of morphine or codeine became characteristic. This change necessitates a new physiological aspect in intraspecific chemotaxonomic evaluation.