Rapid and mass multiplication of three peppermint (Mentha piperita L.) Collections through In vitro Propagation

Nodal segments of three peppermint collections Ludhiana (L), Pantnagar (P) and Sarabha (S) were cultured on the MS basal medium, enriched with various combinations of auxins and cytokinins. Maximum establishment was recorded in ‘L’, (84.30%) followed by ‘S’ (77.50%) and in ‘P’ (77.30%) on MS supplemented with BAP. The average number of shoots per explant ranged from 1.0 to 5.6 in all the three collections. In ‘P’ the maximum number of shoots per explant was 5.6 followed by 4.8 in collection ‘S’ and 4.4 in collection ‘L’ on MS media supplemented with different combinations of BAP and Kinetin. The average shoot length ranged from 3.0cm to 9.6cm depending upon the media and genotype used. The maximum shoot length of 9.6cm was recorded in collection ‘P’ followed by 8.8cm in ‘S’ and the 8.5cm in ‘L on the same media. Supplementation of IBA (0.25 to 1.50mg/l) to MS media induced root regeneration in cultures ranging from 47.00 to 88.00 per cent in all the three collections. Addition of IBA (1.00mg/l) into MS media produced the root length maximally in all the three collections (2.90cm in ‘S’, 2.84cm in ‘P’ and 2.76cm in ‘L’). The highest average number of roots per explant (3.60) was recorded in collection ‘S’ and the lowest average number of roots per explant (1.10) was recorded in ‘L’. The number of days taken for root initiation ranged from the highest (21days) in variety ‘L’ to the lowest (9 days) in variety ‘P’ on root regeneration medium. Present study reports an efficient and reproducible protocol for rapid and mass in vitro multiplication of peppermint cultivars.