Decoupling subgenomes within hybrid lavandin provide new insights into speciation and monoterpenoid diversification of Lavandula

Structure and release function of fragrance glands

Volatile compounds serve physiological, signaling, and defensive purposes in plants and have beneficial effects on the growth, reproduction, resistance, and yield of horticultural plants. They are released through fragrance glands and become gasses by passing through the plasma membrane, cell walls that contain water, and cuticle. Transporter proteins facilitate their transport and reduce the resistance of these barriers. They also regulate the rate of release and concentration of volatiles inside and outside of the membrane. However, there has been no summary of the structure and function of the fragrance glands of horticultural plants, as well as an introduction to the latest research progress on the mechanism of the transport of volatiles. This review focuses on the structure and function of the release of aromas in horticultural plants and explores the mechanism of the release of volatiles through a transporter model. Additionally, it considers the factors that affect their release and ecological functions and suggests directions for future research.

Construction of Simple Sequence Repeat-Based Genetic Linkage Map and Identification of QTLs for Accumulation of Floral Volatiles in Lavender (Lavandula angustifolia Mill.)

In spite of the increasing industrial cultivation of lavender (Lavandula angustifolia Mill.), no genetic linkage map and mapping of QTLs (quantitative trait locus) has been reported for Lavandula species. We present the development of a set of SSR (simple sequence repeat) markers and the first genetic linkage map of lavender following the genotyping of a segregating population obtained by the self-pollination of the industrial lavender variety Hemus. The resulting genetic map comprises 25 linkage groups (LGs) corresponding to the chromosome number of the lavender reference genome. The map includes 375 loci covering a total of 2631.57 centimorgan (cM). The average marker distance in the established map is 7.01 cM. The comparison of the map and reference genome sequence shows that LG maps cover an average of 82.6% of the chromosome sequences. The PCR amplification tests suggest that the developed SSR marker set possesses high intra-species (>93%) and inter-species (>78%) transferability. The QTL analysis employing the constructed map and gas chromatography/mass spectrometry (GC/MS) dataset of flower extracted volatiles resulted in the mapping of a total of 43 QTLs for the accumulation of 25 different floral volatiles. The comparison of the genome location of the QTLs and known biosynthetic genes suggests candidate genes for some QTLs.

Chromosome-scale genome assembly of the 'Munstead' cultivar of Lavandula angustifolia

OBJECTIVES

Lavandula angustifolia (English lavender) is commercially important not only as an ornamental species but also as a major source of fragrances. To better understand the genomic basis of chemical diversity in lavender, we sequenced, assembled, and annotated the 'Munstead' cultivar of L. angustifolia.

DATA DESCRIPTION

A total of 80 Gb of Oxford Nanopore Technologies reads was used to assemble the 'Munstead' genome using the Canu genome assembler software. Following multiple rounds of error correction and scaffolding using Hi-C data, the final chromosome-scale assembly represents 795,075,733 bp across 25 chromosomes with an N50 scaffold length of 31,371,815 bp. Benchmarking Universal Single Copy Orthologs analysis revealed 98.0% complete orthologs, indicative of a high-quality assembly representative of genic space. Annotation of protein-coding sequences revealed 58,702 high-confidence genes encoding 88,528 gene models. Access to the 'Munstead' genome will permit comparative analyses within and among lavender accessions and provides a pivotal species for comparative analyses within Lamiaceae.