1Division of Crop Improvement, Central Potato Research Institute, Shimla, 171 001, Himachal Pradesh, India.
The synergistic effects of two sulfhydryl compounds, viz., L-cysteine and 2-mercaptoethanol each at 0, 2.0, 4.0, 6.0, 8.0 and 10.0 mM during cytokinin-induced microtuberization were studied in two potato (Solanum tuberosum L. subsp. tuberosum) genotypes. The sulfhydryl compounds were tested on induction medium based on Murashige and Skoog's basal medium supplemented with 10 mgl−1 N6-benzyladenine (BA) and 80 gl−1 sucrose. There were significant genotype × sulfhydryl compound interactions for microtuber initiation and development. Except for cysteine which showed a positive influence on microtuber initiation only in early maturing genotype Kufri Ashoka, sulfhydryl compounds in general significantly affected microtuber development. Cysteine at ≥ 4.0 mM inhibited microtuber development. Mercaptoethanol at 2.0 mM increased microtuber fresh mass and microtuber yield. However, increasing concentrations of mercaptoethanol in the medium significantly declined microtuber fresh mass and yield. Thus 2.0 mM mercaptoethanol can be used in the induction medium to improve potato microtuber production and utilization efficiency during cytokinin-induced tuberization in vitro.
