RESUMEN
Velvet bean (Mucuna pruriens) seeds contain the catecholic amino acid L-DoPA (L-3,4-dihydroxyphenylalanine), which is a neurotransmitter precursor and used for the treatment of Parkinson's disease and mental disorders. The great demand for L-DoPA is largely met by the pharmaceutical industry through extraction of the compound from wild populations of this plant; commercial exploitation of this compound is hampered because of its limited availability. The trichomes present on the pods can cause severe itching, blisters and dermatitis, discouraging cultivation. We screened genetic stocks of velvet bean for the trichome-less trait, along with high seed yield and L-DoPA content. The highest yielding trichome-less elite strain was selected and indentified on the basis of a PCR-based DNA fingerprinting method (RAPD), using deca-nucleotide primers. A genetic similarity index matrix was obtained through multivariant analysis using Nei and Li's coefficient. The similarity coefficients were used to generate a tree for cluster analysis using the UPGMA method. Analysis of amplification spectra of 408 bands obtained with 56 primers allowed us to distinguish a trichome-less elite strain of M. pruriens.
Asunto(s)
Levodopa/biosíntesis , Mucuna/genética , Semillas/genética , Pruebas Genéticas , Genotipo , Mucuna/química , Mucuna/metabolismo , Técnica del ADN Polimorfo Amplificado Aleatorio , Semillas/química , Semillas/enzimologíaRESUMEN
The genus Swertia is well known for its medicinal properties, as described in the Indian pharmacopoeia. Different members of this genus, although somewhat similar in morphology, differ widely in their pharmacological and therapeutic properties. The most important species of this genus, with maximal therapeutic properties, is S. chirayita, which is often adulterated with other less-potent Swertia spp. There is an existing demand in the herbal drug industry for an authentication system for Swertia spp, in order to enable their commercial use as genuine phytoceuticals. To this end, we used amplified fragment length polymorphism (AFLP) to produce DNA fingerprints for six Swertia species. Nineteen accessions (2 of S. chirayita, 3 of S. angustifolia, 2 of S. bimaculata, 5 of S. ciliata, 5 of S. cordata, and 2 of S. alata) were used in the study, which employed 64 AFLP selective primer pairs. Only 46 selective primer pairs were found to be useful for all the accessions. A total of 5312 fragments were produced by these 46 primer pairs. Species-specific markers were identified for all six Swertia species (131 for S. chirayita, 19 for S. angustifolia, 181 for S. bimaculata, 47 for S. ciliata, 94 for S. cordata, and 272 for S. alata). These AFLP fingerprints of the Swertia species could be used to authenticate drugs made with Swertia spp and to resolve adulteration-related problems faced by the commercial users of these herbs.