Figure 1.

Plant morphology and genome features of Cymbidium sinense. (a) Morphological character of wild and variated types of floral organs, flower colours and leaf colours in C. sinense plants. a1. The unique floral organ includes three sepals in the first whorl, three petals in the second whorl and productive parts in the centre of the flower. The male and female productive organs are highly fused to form a gynostemium (or column), which evolved through complete fusion of the style, stigma and staminal filament and has four pollinia on a semi‐circular viscidium. The sepals and petals together are called the tepals. Among them, two of the petals are similar to each other and resemble unmodified sepals, while the third is highly modified and is called the labellum (or lip). Se, sepal, Pe, petal, Li, lip and Co, column; a2. Natural mutant (varieties) of flower types. The first row, specialization of the labellum reduced or transformed into petals, is named as lotus petals or null‐labellum varieties. The second row, the labellum expanded, sepals or petals are transformed into labellum‐like structure. The third row, the gynostemium (column) expanded, petals are transformed into Genostemium‐like structure. In the fourth row, multi‐tepal flowers develop more tepals; a3. different flower colours of C. sinense, including green, yellow, red and black; a4. Natural mutant of leaf colours. (b) High‐quality genome of C. sinense allows integration of genetic and expression data. From the inside out, Circle1. The assembled 20 chromosomes; Circle2. Gene density plotted in a 500‐kb sliding window; Circle3. Transposable element (TE) density plotted in a 500‐kb sliding window; Circle4. GC content plotted in a 500‐kb sliding window; Circle5. Intragenomic syntenic regions denoted by a single line represent a genomic syntenic region covering at least 20 paralogues.