Evaluation of nature and magnitude of heterosis in ashwagandha [Withania somnifera (L.) Dunal] for root quality and yield parameters

Abstract

Ashwagandha is one of the important medicinal plant commercially cultivated for long period. The investigation was performed in Randomized Complete Block Design for seventeen traits of seven parental lines which were crossed and some reciprocal cross also made for the estimation of root yield and quality during Rabi 2018-19 were studied to assess the magnitude of heterosis in ashwagandha. The result obtained were the cross CGWS.92xCGWS.90, CGWS.92xCGWS.93, CGWS.93xCGWS.89 and CGWS.93xCGWS.92 recorded negative heterosis over better parent for days to 50% flowering, which indicates that scope for its utilization in evolving early flowering plant types. Significant and positive heterosis was found in the cross viz., CGWS.89xCGWS.90, CGWS.89xCGWS.92, CGWS.93xCGWS.89, CGWS.94xCGWS.91 over better parent, and standard checks JA-20 and JA-134 for plant height. For no. of main branches/plant the significant positive heterosis was recorded in cross CGWS.89xCGWS.90, CGWS.90xCGWS.92, CGWS.90xCGWS.93, CGWS.91xCGWS.90 over better parent, standard checks JA-20, JA-134 and RVA-100. Similarly, for no. of secondary branches/plants was recorded in cross CGWS.91xCGWS.89, CGWS.94xCGWS.91, CGWS.95xCGWS.91 over better parent, standard checks JA-20, JA-134 and RVA-100. The cross CGWS.90xCGWS.93, CGWS.91xCGWS.90, CGWS.93xCGWS.92 was found significant and positive heterosis for no. of plant/plot over better parent, standard checks JA-20 and RVA-100. For root length significant and positive heterosis over better parent, standard checks JA-134 was recorded in cross CGWS.92xCGWS.90, CGWS.93xCGWS.91. Significant and positive heterosis recorded in cross CGWS.89xCGWS.91, CGWS.89xCGWS.92, CGWS.89xCGWS.93, CGWS.90xCGWS.92, CGWS.91xCGWS.89, CGWS.91xCGWS.92, CGWS.92xCGWS.89, CGWS.92xCGWS.93, CGWS.93xCGWS.89, CGWS.93xCGWS.92, CGWS.94xCGWS.90, CGWS.95xCGWS.92 over better parent, standard checks RVA-100 for fresh root weight/plant. For dry root weight/plant the significant and positive heterosis were recorded in cross CGWS.89xCGWS.90, CGWS.89xCGWS.91, CGWS.92xCGWS.90, CGWS.92xCGWS.93 over better parent, standard checks JA-20 and RVA-100. The low fiber content in root (%) of ashwagandha is preferred, significant and negative heterosis reported in the cross viz., CGWS.90xCGWS.92, CGWS.91xCGWS.90, CGWS.94xCGWS.91 over better parent and standard checks (JA-20) for fiber content in root (%). The best cross out of 20 crosses, two heterotic F1 with high fresh root weight per plant, high carbohydrate content (%), high protein content (%) and low fiber content in root (%), were found in cross CGWS.90 x CGWS.92 and CGWS.94 X CGWS.91 over standard check. These high root weight, carbohydrate content, protein content and low fiber content in F1 hybrid may be recommended for commercial exploitation.