SCAR markers for correct identification of Phyllanthus amarus, P. fraternus, P. debilis and P. urinaria used in scientific investigations and dry leaf bulk herb trade

Abstract

The trade in Phyllanthus material as bulk herb is rampant and mainly involves herbaceous species such as Phyllanthus amarus, P. fraternus, P . debilis and P. urinaria. These species are very important in herbal medicines and have varied activities. In India these species grow sympatrically and there are chances of deliberate or ignorant adulteration of crude drugs, lowering the efficiency of the medication for its intended purpose. Secondly, incorrect identification may also lead to erroneous reports on activities/molecules. To overcome this problem in crude drug (dry leaf powder) and compliment morphological identification in live plant, we have developed SCAR markers for all four species. In each species, we selected one fragment as being monomorphic between accessions but differing in size between species. These species-specific fragments were selected, cloned and sequenced. Based on the sequences, primer pairs were designed and amplification conditions standardized. SCAR markers were isolated from population DNA amplification profiles and validated by sequencing. The species-specific SCAR primers could retrieve the same size and sequence of fragments as in the RAPD profile. These fragments are 1150 bp, 317 bp, 980 bp and 550 bp in size for P. amarus, P. fraternus, P. debilis and P. urinaria, respectively. Additional fragments in P. debilis and P. urinaria indicate different alleles. The retrieval of same size and sequence of species-specific unique SCAR markers from the respective accessions (mixed DNA sample of same accessions) indicates the usefulness to study natural hybridization between the species in addition to adulteration.