Showing papers by "Damon P. Little published in 2013"
TL;DR: Mini–barcode analysis of saw palmetto dietary supplements demonstrated that 29 (85%) contain saw Palmetto and that 2 (6%) supplements contain related species that cannot be legally sold as herbal dietary supplements in the United States of America.
Abstract: Herbal dietary supplements made from saw palmetto (Serenoa repens; Arecaceae) fruit are commonly consumed to ameliorate benign prostate hyperplasia. A novel DNA mini–barcode assay to accurately identify [specificity = 1.00 (95% confidence interval = 0.74–1.00); sensitivity = 1.00 (95% confidence interval = 0.66–1.00); n = 31] saw palmetto dietary supplements was designed from a DNA barcode reference library created for this purpose. The mini–barcodes were used to estimate the frequency of mislabeled saw palmetto herbal dietary supplements on the market in the United States of America. Of the 37 supplements examined, amplifiable DNA could be extracted from 34 (92%). Mini–barcode analysis of these supplements demonstrated that 29 (85%) contain saw palmetto and that 2 (6%) supplements contain related species that cannot be legally sold as herbal dietary supplements in the United States of America. The identity of 3 (9%) supplements could not be conclusively determined.
52 citations
TL;DR: Comparative analyses of sequence quality and species discrimination were conducted on the 159 individuals from which all three markers were recovered, finding that the vast majority of sequences were of high quality and even the lowest quality sequences exceeded the minimum requirements of the BARCODE data standard.
Abstract: We have generated matK, rbcL, and nrITS2 DNA barcodes for 320 specimens representing all 18 extant genera of the conifer family Podocarpaceae. The sample includes 145 of the 198 recognized species. Comparative analyses of sequence quality and species discrimination were conducted on the 159 individuals from which all three markers were recovered (representing 15 genera and 97 species). The vast majority of sequences were of high quality (B30 = 0.596–0.989). Even the lowest quality sequences exceeded the minimum requirements of the BARCODE data standard. In the few instances that low quality sequences were generated, the responsible mechanism could not be discerned. There were no statistically significant differences in the discriminatory power of markers or marker combinations (p = 0.05). The discriminatory power of the barcode markers individually and in combination is low (56.7% of species at maximum). In some instances, species discrimination failed in spite of ostensibly useful variation being present (genotypes were shared among species), but in many cases there was simply an absence of sequence variation. Barcode gaps (maximum intraspecific p–distance > minimum interspecific p–distance) were observed in 50.5% of species when all three markers were considered simultaneously. The presence of a barcode gap was not predictive of discrimination success (p = 0.02) and there was no statistically significant difference in the frequency of barcode gaps among markers (p = 0.05). In addition, there was no correlation between number of individuals sampled per species and the presence of a barcode gap (p = 0.27).
35 citations
TL;DR: Within-host interactions between PAV and PAS create conditions that promote both the competitive exclusion of PAS, as well as co-existence between species and the maintenance of genetic diversity in the host community.
11 citations
TL;DR: The purpose of the study by Meyer et al. was to use new and expanded accession sets coupled with molecular data to evaluate possible scenarios of eggplant domestication with as little influence as possible from any previously published nomenclatural scheme, and taking into consideration multiple sources of evidence regarding the history of Eggplant in Asia.
2 citations