Plant materials and estimation of genome size
The plants ofO.
kokonorica were collected from east side of the Qinghai Lake, Qinghai
province, China. Fresh leaves of O. kokonorica were used to
extract genomic DNA using a DNA Secure Plant Kit (Tiangen Biotech, Co.,
Ltd., Beijing, China). Paired-end libraries with insert sizes of 150 bp
were constructed and sequenced using the Illumina HiSeq X Ten platform.
We used K-mer frequency distribution analysis to estimate genome size
(Li et al., 2010). To calculate and plot the K-mer frequency
distribution, we used 35.29 Gb of Illumina short reads (Table S1) to
determine the total number of K-mers of length 27 using Jellyfish
(Marçais & Kingsford, 2011). The selection of 27-mers to plot the
frequency distribution was based on genome characteristics and the
pattern of the Poisson distribution (Figure S1). We evaluated the ploidy
level of this genome using
Smudgeplot
(Ranallo-Benavidez et al., 2020).