ISHS Acta Horticulturae 675: III WOCMAP Congress on Medicinal and Aromatic Plants - Volume 1: Bioprospecting and Ethnopharmacology
STABILITY AND VARIABILITY OF ALKALOID ACCUMULATION IN POPPY (PAPAVER SOMNIFERUM L.) INDUCED BY CROSSING |
| Authors: | J. Bernáth, E. Németh |
| Keywords: | alkaloid biosynthesis, alkaloid-free cultivars, F1 generation, metaxenia, morphine, codeine, thebaine, narcotine |
| Abstract:
Five poppy cultivars of high chemical diversity ‘Kheops’, ‘A1’, ‘Tebona’, ‘Kék Gemona’ and ‘Przemko’ were selfed and crossed in 2000. The hybrid generations (F1) were grown in 2001. When the castrated alkaloid free cultivar ‘Przemko’ (accumulating only 0.01 mg/g morphine in capsules) was pollinated with cultivars rich in alkaloids, the morphine content of its capsules increased to 0.9-7.5 mg/g values, even in the year of the crossing. The same phenomenon was observed in the F1 generation, however the appearance of alkaloids became more characteristic showing intermediate type of inheritance (4.8-6.4 mg/g morphine was accumulated). Based on the well known biosynthetic background of poppy alkaloids, this can be explained by the promotion of (S)-norcoclaurine synthesis, which seems to be suppressed in alkaloid-free plants, but both tissues of the developing hybrid seeds (in a form of chemical metaxenia) and the genetic combination in the F1 can release this suppression. In particular, the appearance of narcotine in narcotine-free cultivars ‘Kheops’, ‘A1’ and ‘Przemko’ (0.1-1.1 mg/g in the year of crossing and 2.4 mg/g in F1 generation) can be explained similarly. If the narcotine-type plants ‘Kék Gemona’ (accumulating 7.0-11.3 mg/g narcotine) were used for pollination the developing seed tissue, or the genetic combination in the F1 might contribute to the suppression of the activity of 1,2-dehydroreticuline reductase, which leads to the accumulation of narcotine at the cost of morphinanes. | |
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