Variability in L-Dopa and other biochemical composition of Mucuna pruriens (L.) an underutilized tropical legume

Mucuna pruriens (L.) is an important underutilized legume medicinal plant. It is an herbaceous annual twining climber. Its seeds are used to extract the L-Dopa (L-3, 4-dihydroxyphenylalanine) to the preparation of the drugs and are used in the treatment of Parkinson’s disease. Mucuna seeds are rich source of L-Dopa in addition to protein and other minerals. In the present study estimation of L-Dopa and other biochemical traits in 58 genotypes of velvet bean has been analyzed to identify the genotypes having maximum seed yield coupled with high L-Dopa to the preparation of drugs. The L-Dopa is varied significantly from 2.94 to 6.91% among mucuna genotypes. The levels of total phenol content and tannins varied significantly among genotypes and ranged from 27.73 to 103.50 mg/100 g and 0.18 to 0.96 mg/100 g DW, respectively. The protein content in the estimated genotypes of Mucuna seed greatly varied from 19.08% to 38.18% with a mean value of 28.16%. Significantly maximum L-Dopa, total phenol content, total tannin, crude protein, fat and carbohydrate was recorded in IIHR MP 62-1 (6.91%), IIHR MP 62-2 (103.50 mg/100 g), IIHR MP 63-1 (0.96 mg/100 g), IIHR MP-74 (38.18%), IIHR MP 95 (7.54%) and IIHR MP 62-3 (64.36%), respectively. Significantly low L-Dopa, total phenol content, total tannin found in IC 332432 (2.94%), IIHR MP 89-1 (27.73 mg/100 g), IIHR MP 10 (0.183 mg/100 g), respectively. Biochemical traits viz., crude protein, fat and carbohydrate found less in EC 17827 (19.08%), IIHR MP 62-3 (3.10%) and IIHR MP 74 (47.81%), respectively. Cluster analysis based on biochemical data revealed that the cluster I showed highest mean value for L-Dopa and total phenol content, cluster III for total tannin and cluster VI for crude protein. The results showed that intra cluster distance was maximum in cluster VI (167.51) and maximum inter cluster distance was between cluster I and V (2014.94). Total phenol content was the main contributor to the total genetic divergence. The traits fat and L-Dopa were moderately contributing and carbohydrate was least contributing to the total divergence of the estimated biochemical traits. The genotypes belonging to the cluster with maximum inter cluster distance are genetically more divergent and these genotypes could be used in the hybridization programme of velvet bean to evolve high L-Dopa type to meet the demand of drug industry.