Development of Prediction Model and Experimental Validation in Predicting the Curcumin Content of Turmeric (Curcuma longa L.).

The drug yielding potential of turmeric (Curcuma longa L.) is largely due to the presence of phyto-constituent 'curcumin.' Curcumin has been found to possess a myriad of therapeutic activities ranging from anti-inflammatory to neuroprotective. Lack of requisite high curcumin containing genotypes and variation in the curcumin content of turmeric at different agro climatic regions are the major stumbling blocks in commercial production of turmeric. Curcumin content of turmeric is greatly influenced by environmental factors. Hence, a prediction model based on artificial neural network (ANN) was developed to map genome environment interaction basing on curcumin content, soli and climatic factors from different agroclimatic regions for prediction of maximum curcumin content at various sites to facilitate the selection of suitable region for commercial cultivation of turmeric. The ANN model was developed and tested using a data set of 119 generated by collecting samples from 8 different agroclimatic regions of Odisha. The curcumin content from these samples was measured that varied from 7.2% to 0.4%. The ANN model was trained with 11 parameters of soil and climatic factors as input and curcumin content as output. The results showed that feed-forward ANN model with 8 nodes (MLFN-8) was the most suitable one with R2 value of 0.91. Sensitivity analysis revealed that minimum relative humidity, altitude, soil nitrogen content and soil pH had greater effect on curcumin content. This ANN model has shown proven efficiency for predicting and optimizing the curcumin content at a specific site.

Differential effect of soil and environment on metabolic expression of turmeric (Curcuma longa cv. Roma).

Curcuma longa (Zingiberaceae) is known for its uses in medicine, cosmetics, food flavouring and textile industries. The secondary metabolites of turmeric like essential oil, oleoresin and curcumin are important for its multipurpose uses. These traits of turmeric vary from place to place due to the influence of environment, soil and agro-climatic conditions. Here, we analyzed turmeric from different agroclimatic regions for influence of various factors on its growth and yield of important phytochemicals. A high curcumin yielding cultivar i.e., Roma was collected from high altitude research station, Koraput (HARS) and planted in nine agroclimatic regions of Odisha. Analysis of soil texture, pH, organic carbon, micro and macro nutrients were done from all the studied zones up to 2nd generation. Plants grown in their released station i.e., Eastern Ghat High Land showed 5% of curcumin and were taken as control. Plants grown in different agroclimatic zones showed a range of 1.4-5% of curcumin and 0.3-0.7% of rhizome essential oil and 0.3-1% of leaf essential oil content. Gas chromatography and mass spectra analysis showed tumerone and alpha phellandrene as the major compounds in all the zones with 10-20% variation. The present study will be immensely helpful for standardization and management of environmental and ecological factors for high phytochemical yield in turmeric plant.