High Resolution Melting (HRM) Genotyping in the Genus Origanum: Molecular Identification and Discrimination for Authentication Purposes

Identification and validation of intergeneric hybrids between Saccharum officinarum and Erianthus rockii using molecular and cytogenetic tools

Sugarcane (Saccharum spp.), a vital crop for sugar and bioenergy production, faces challenges in breeding due to its narrow genetic base and susceptibility to environmental stresses. To enhance genetic diversity, distant hybridization with wild relatives such as Erianthus rockii, known for its drought tolerance and strong ratooning ability, offers a promising strategy. However, identifying true intergeneric hybrids remains a critical challenge. This study identified true intergeneric hybrids from crosses between S. officinarum and E. rockii using tetra-primer ARMS-PCR and HRM curve analysis targeting SNPs in the nrDNA-ITS region, with genomic in situ hybridization (GISH) validating chromosome composition. The results confirmed 13 true hybrids among 16 progeny, showing a chromosome inheritance pattern of 40 chromosomes derived from S. officinarum and 15 from E. rockii. Hybrid plants, while exhibiting traits from both parents, displayed inferior yield and sugar content compared to the maternal parent, indicating the necessity for further backcrossing to improve agronomic performance. This study pioneers the application of ARMS-PCR and HRM in identifying E. rockii hybrids and underscores their potential in advancing sugarcane breeding by facilitating the introgression of beneficial traits from wild relatives.

Challenges in Medicinal and Aromatic Plants DNA Barcoding-Lessons from the Lamiaceae

The potential value of DNA barcoding for the identification of medicinal plants and authentication of traded plant materials has been widely recognized; however, a number of challenges remain before DNA methods are fully accepted as an essential quality control method by industry and regulatory authorities. The successes and limitations of conventional DNA barcoding are considered in relation to important members of the Lamiaceae. The mint family (Lamiaceae) contains over one thousand species recorded as having a medicinal use, with many more exploited in food and cosmetics for their aromatic properties. The family is characterized by a diversity of secondary products, most notably the essential oils (EOs) produced in external glandular structures on the aerial parts of the plant that typify well-known plants of the basil (Ocimum), lavender (Lavandula), mint (Mentha), thyme (Thymus), sage (Salvia) and related genera. This complex, species-rich family includes widely cultivated commercial hybrids and endangered wild-harvested traditional medicines, and examples of potential toxic adulterants within the family are explored in detail. The opportunities provided by next generation sequencing technologies to whole plastome barcoding and nuclear genome sequencing are also discussed with relevant examples.