Jenö Bernáth

Variation in alkaloid production in poppy ecotypes: responses to different environments

Abstract Papaver somniferum cultivars of European and Asiatic origin have been grown under controlled condition in growth chambers simulating Hungarian long-day (14 h) and tropical climatic conditions (10 h + high light intensity). The changes in plant development and the alteration in primary and secondary metabolites were determined. Long-day conditions accelerated the development of all cultivars. European cultivars started fiowering on day 68–70, Afghan and Thai on day 58–60, while Indian plants flowered on day 55 after sowing. However, under short-day conditions retardation was obvious (5–15 days) dependent on plant origin. The amount of total alkaloids accumulated in capsules was usually higher under tropical conditions characterized by higher temperature and illumination. To interpret the relative importance of genetical and ecological interactions a new evaluation method was introduced. This has shown that (a) the European cultivars ‘Kek Duna’ and ‘Reading’ differ from all others in any ecological circumstances: (b) the Indian ecotype also shows marked separation and (c) Thai and Afghan ecotypes are closely related.

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.

The effect of environmental factors on growth. Development and alkaloid production of poppy (Papaver somniferum L.). I. Responses to day-length and light intensity

Summary Short-day rhythm hindered the stem growth (by 45—60 %), the flower initiation (by 3—45 days), and the alkaloid acrumulation (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· 104 lux to 3.2· 104 lux) accelerated growth and development of the three cultivars investigated: optimum growth occurs at 1.6· 104 lux, whereas optimum development was observed at 3.2· 104 lux. Similarly, the alkaloid biosynthesis increases 2—3 times at higher light intensity of long-day treatments (2.4—3.2· 104 lux). At the same time the proportion of the higher methylated alkaloid components rises. In the case of certain cultivars, depending on light condition, the presence either of morphine or codeine became characteristic. This change necessitates a new physiological aspect in infraspecific chemotaxonomic evaluation.