Sequencing and comparative analyses of the genomes of zoysiagrasses

Abstract

Zoysia is a warm-season turfgrass, which comprises 11 allotetraploid species (2n = 4x = 40), each possessing different morphological and physiological traits. To characterize the genetic systems of Zoysia plants and to analyse their structural and functional differences in individual species and accessions, we sequenced the genomes of Zoysia species using HiSeq and MiSeq platforms. As a reference sequence of Zoysia species, we generated a high-quality draft sequence of the genome of Z. japonica accession ‘Nagirizaki’ (334 Mb) in which 59,271 protein-coding genes were predicted. In parallel, draft genome sequences of Z. matrella ‘Wakaba’ and Z. pacifica ‘Zanpa’ were also generated for comparative analyses. To investigate the genetic diversity among the Zoysia species, genome sequence reads of three additional accessions, Z. japonica ‘Kyoto’, Z. japonica ‘Miyagi’ and Z. matrella ‘Chiba Fair Green’, were accumulated, and aligned against the reference genome of ‘Nagirizaki’ along with those from ‘Wakaba’ and ‘Zanpa’. As a result, we detected 7,424,163 single-nucleotide polymorphisms and 852,488 short indels among these species. The information obtained in this study will be valuable for basic studies on zoysiagrass evolution and genetics as well as for the breeding of zoysiagrasses, and is made available in the ‘Zoysia Genome Database’ at .

Functional and RNA-Sequencing Analysis Revealed Expression of a Novel Stay-Green Gene from Zoysia japonica (ZjSGR) Caused Chlorophyll Degradation and Accelerated Senescence in Arabidopsis

“…It has been a desire of the turfgrass breeders for a long time to cultivate zoysiagrass cultivars with longer green period and better visual appearance. Nevertheless, limited genetic resources are available for zoysiagrass to date (Wei et al, 2015; Tanaka et al, 2016), and the senescence mechanism are far from being well-illustrated. The objectives of this study were: (i) to identify a stay-green protein gene in Z. japonica ; (ii) to investigate its characters and explore its functional roles; and (iii) to further explore its regulatory network in senescence.…”

The Highly Heterozygous Homoploid Turfgrass Zoysia matrella Displays Desirable Traits in the S1 Progeny

“…have supported the hypothesis that Z. matrella is a homoploid species and is more heterozygous than Z. japonica or Z. pacifica (Tanaka et al, 2015(Tanaka et al, , 2016. Similarly, homoploid hybrid speciation has been recently studied for its active role in the development of new species.…”

“…Similarly, homoploid hybrid speciation has been recently studied for its active role in the development of new species. Self-pollination increases the expression of genetic variance (Poehlman and Sleper, 1995;Tanaka et al, 2016) due to increased homozygosity and the expression of deleterious recessive alleles (Wricke and Weber, 1986;Husband and Schemske, 1996;Charlesworth and Willis, 2009). In recent studies, comparison of genome structures and morphological analyses in Zoysia spp.…”

“…Recently, comparative analyses of the genomes of Z. japonica, Z. matrella, and Z. pacifica have revealed higher heterozygosity in the genome of Z. matrella as compared with those of the two other species and thereby elucidated the homoploid nature of Z. matrella (Tanaka et al, 2016). Zoysia matrella 'Wakaba' is an ecotype from Nango town, Miyazaki, Japan, and was one of the Zoysia materials used for genome analysis.…”

“…Since Z. matrella was suggested to be an interspecific hybrid of Z. japonica and Z. pacifica using SSR markers and was later confirmed as a homoploid hybrid by whole-genome sequencing (Tanaka et al, 2015;Tanaka et al, 2016), the self-pollination method might be an important key to further investigate genetics of zoysiagrass and a useful tool in breeding programs of Zoysia. The SSR marker is an informative, codominant marker system commonly used in the study of genetic diversity, inheritance, and marker-assisted selection.…”