The alkaloid content of poppy (Papaver somniferum L.) varieties in Turkey by their correlation and path coefficient relationships

The research was conducted with the aim of examining the alkaloids content of twelve poppies (Papaver somniferum L.) cultivars registered in Turkey by correlation and path analysis of relationships among alkaloids with capsule yield. The field experiments were set up according to a randomized complete block design with three replications in 2017-18 and 2018-19 under the semi-arid ecological conditions of Isparta, Turkey. The differences among the capsule yields and alkaloid contents of poppy varieties were statistically significant (P≤0.01) in both periods, and the capsule yields were determined to be between 253.4-556.2 kg ha-1 in the first year and 332.7-659.2 kg ha-1 in the second year. The morphine, codeine, oripavine, thebaine, papaverine, and noscapine contents of poppy cultivars varied between 0.46-1.84%, 0.08-0.30%, 0.009-0.057%, 0.031-0.093%, 0.002-0.047% and 0.017-0.094%, respectively. According to correlation analysis, the relationships between the morphine content with codeine (r=0.415*), oripavine (r=0.362*), and papaverine (r=0.624**) were significant and positive while noscapine (r=0.164ns) and thebaine (r=0.043ns) were insignificant and positive. In the path coefficient analysis, papaverine (p=0.631, 67.75%) had the highest direct effect on morphine content followed by thebaine, orpavine, and noscapine, respectively. Noscapine had the highest indirect positive effect on morphine content via papaverine while thebaine had negative and high indirect effects via papaverine. In the study, varieties that could be recommended for the semi-arid ecological conditions of Turkey were the TMO-1 and TMO-3 varieties due to higher capsule yields and the Ofis-1 variety due to the high alkaloid content.