Diploid mint (M. longifolia) can produce spearmint type oil with a high yield potential

Nestor Kippes,Eric Dowd,Darrin Culp,Brian Mccormack,Meric Lieberman,Rob G Wilson,Isabelle M Henry,Luca Comai,Helen Tsai

doi:10.1038/s41598-021-02835-6

Nestor Kippes, Eric Dowd + Show 7 more

Open Access

https://doi.org/10.1038/s41598-021-02835-6

Copy DOI

Abstract

Mint oil is a key source of natural flavors with wide industrial applications. Two unbalanced polyploid cultivars named Native (Mentha Spicata L) and Scotch (M. × gracilis Sole) are the main producers of spearmint type oil, which is characterized by high levels of the monoterpenes (−)-carvone and (−)-limonene. These cultivars have been the backbone of spearmint oil production for decades, while breeding and improvement remained largely unexplored, in part, due to sterility in cultivated lines. Here we show that sexual breeding at the diploid level can be leveraged to develop new varieties that produce spearmint type oil, along with the improvement of other important traits. Using field trials and GC-FID oil analysis we characterized plant materials from a public germplasm repository and identified a diploid accession that exhibited 89.5% increase in oil yield, compared to the industry standard, and another that produces spearmint type oil. Spearmint-type oil was present at high frequency in a segregating F2 population (32/160) produced from these two accessions. Field-testing of ten of these F2 lines showed segregation for oil yield and confirmed the production of spearmint-type oil profiles. Two of these lines combined high yield and spearmint-type oil with acceptable analytic and sensory profiles. These results demonstrate that spearmint-type oil can be produced in a diploid background with high yield potential, providing a simpler genetic system for the development of improved spearmint varieties.

Highlights

Mint oil is a key source of natural flavors with wide industrial applications
We provide a detailed characterization of the genetic variation available for traits that are not commonly explored in plant conservation studies, such as oil yield, biomass production and oil quality under standardized field conditions with distillation at pilot plant scale
Our analysis of genetic diversity indicates that M. longifolia is a highly diverse subspecies

Summary

Introduction

Mint oil is a key source of natural flavors with wide industrial applications. Two unbalanced polyploid cultivars named Native (Mentha Spicata L) and Scotch (M. × gracilis Sole) are the main producers of spearmint type oil, which is characterized by high levels of the monoterpenes (−)-carvone and (−)-limonene. × gracilis Sole) are the main producers of spearmint type oil, which is characterized by high levels of the monoterpenes (−)-carvone and (−)-limonene. These cultivars have been the backbone of spearmint oil production for decades, while breeding and improvement remained largely unexplored, in part, due to sterility in cultivated lines. The combination of stagnant yields with the lack of expansion of mint acreage in the US in the last decades presents a challenge for the long-term supply of high-quality mint oil, and a great opportunity to produce transformative improvements in this industry such as more efficient farming and more flavor choices for consumers. The effect of natural allelic diversity in structural and regulatory genes of these pathways is largely unknown, presenting a great opportunity for the discovery of new genetic variants to modulate the relative abundances of the individual flavor components

Methods

Results

Conclusion