Endogenous phytonutrient, phytochemical, and phytohormone levels modulate in-vitro callus induction and plant regeneration in finger millet (Eleusine coracana) genotypes

Abstract

Finger millet (Eleusine coracana) is an orphan crop that has prominent nutritional traits such as high calcium. Biotechnological interventions in this crop suffer from constraints like genotypic dependency leading to inefficient regeneration and transformation systems. Biofortification requires improvements in the available plant tissue culture methods with major emphasis on underutilized crops like finger millet. Keeping this in view, the impact of inherent composition of phytonutrients (calcium, carbohydrates, proteins), phytochemicals (phenolics and flavonoids), and phytohormones (Abscisic Acid, ABA and Gibberellic Acid, GA₃) on tissue culture responsiveness of four finger millet genotypes was studied. The study elucidated that the nutritional and phytochemical/hormone composition of seed/mature embryos as explants influence callus induction and regeneration on use of different phytohormones. There was significant (p < 0.05) callus induction at 1.5 mg/L 2, 4-D (2,4-Dichlorophenoxyacetic Acid) and 0.5 mg/L BAP (6-Benzylaminopurine) in all four genotypes. The high calcium variety GP-45 showed enhanced callusing and regeneration in comparison to other genotypes. Callus Induction Frequency and Shoot Regeneration Frequency exhibited significant positive correlation with calcium content and significant negative correlation with protein and flavonoid content for all the genotypes. The results demonstrate the importance of genotype selection based on inherent phytonutrient and phytohormone composition on tissue culture for crop improvement.

Keywords:

• Finger millet
• plant tissue culture responsiveness
• genotypes
• phytonutrients
• phytochemicals
• phytohormones

Acknowledgements

The authors wish to acknowledge Department of Biotechnology, Govt. of India for providing financial support (project code 7069) and fellowship (Ref: DBT/JRF/14/FIN/52) during the period of study and Dr. Israr Ahmad, N. Pavithran and Dr. Ram Sewak Singh Tomar for their help and support.

Disclosure statement

No potential conflict of interest was reported by the authors.