Assessment of Agronomic Traits and Essential Oil Yield in Various Local Mint (Mentha piperita L.) Genotypes

Abstract

Objective: Mentha piperita L. has long been used in medicine, pharmaceutical industry, food and cosmetic industries due to the bioactive compounds it contains. This study was carried out to determine some agronomic characteristics and essential oil yield of mint genotypes collected from different regions of Ordu province. Materials and Methods: A total of 44 different genotypes collected from 16 different districts of Ordu province were used in the study. Rooted mint cuttings were grown in unheated plastic greenhouse in balcony type plastic pots. Mint plants were harvested in 3 different periods and shoot length, leaf width, leaf length, colour characteristics, leaf chlorophyll index, total yield and essential oil yield were determined. Principal component analyses were performed using the data obtained from these traits. Unweighted pair group method algorithm (UPGMA) clustering analysis was performed using Euclidean similarity distance and dendrograms of genotypes were formed. Results: At the end of the study, plant length was 12.2-60.6 cm, leaf width 0.8-4.3 cm, leaf length 1.2-9.8 cm, leaf chlorophyll index 4.75-47.8 cci (SPAD), essential oil yield 0.45-2.9% and total yield 0.1-4.2 t da-1 in mint genotypes. As a result of the principal component analysis, the eigenvalues of the first 4 principal component axes were found to be greater than 1. The first 3 axes have high variation percentage compared to other axes. Mint genotypes were divided into 2 main groups and 4 subgroups in the UPGMA dendrogram. While G12 and G33 were the closest mint genotypes, G10 and G11 were found to be genetically distant genotypes. Conclusion: In the study, genotypes that exhibit potential in terms of total yield and essential oil yield have been identified. As a result of the research, agronomic characteristics and essential oil ratios of different mint genotypes were determined and qualified genotypes that can be material for future breeding studies were determined.