Genetic variability and correlations of essential oil yield with agro-economic traits in Mentha species and identification of promising cultivars

Mint is an important medicinal and aromatic plant, belongs to 'Lamiaceae' family. Its oil contains large number of aroma chemicals like menthol, menthone, isomenthone, menthyl acetate and menthofuran which are used in pharmaceutical, food, flavor, cosmetics and beverage industries. The hydro distilled essential oils of twenty seven cultivars of six Mentha species, viz. Mentha arvensis L., Mentha piperita, Mentha spicata L. Mentha citrata Ehrh., Mentha spicata L.var. virdis and Mentha cardiaca were analyzed and compared by gas chromatography and gas chromatography-mass spectrometry. Agro-morphological and chemical analysis data of all twenty seven varieties of six Mentha species were evaluated. Variation among twenty seven varieties was significant for all economic traits indicating nature and amount of genetic variations. Genetic variation and correlations studies revealed the significant and positive genetic association between number of internodes and thickness of sucker (0.49**), oil content (%) with thickness of sucker (0.49**) and oil yield (unit per urea) with oil content (0.87**). Correlation/s of fresh herb yield with plant height (46*), oil yield with thickness of sucker (0.43*), oil yield with number of internodes (43*), oil content (%) with number of internodes (42*) were also significant and positive. Therefore, these traits may be considered for the selection of high yielding cultivars through correlated response to selection.