SSR Allelic Diversity Shifts in Zoysiagrass (Zoysia spp.) Cultivars Released from 1910 to 2016

Abstract

Z oysiagrass (Zoysia spp. Willd.) is a warm-season, perennial turfgrass with relatively high heat and drought tolerance, which helps to reduce the input of supplemental irrigation. Of the 11 species of Zoysia, only two [Zoysia japonica Steud. and Zoysia matrella (L.) Merr.] are currently used for turfgrass production in the United States, but other Zoysia spp. are useful as sources to integrate new traits such as smaller leaf size, drought tolerance, and disease resistance (Engelke, 2000a; Engelke and Anderson, 2003). Zoysiagrasses are allotetraploid species (2n = 4x = 40) with a small genome size of 421 Mbp (Cai et al., 2005; Harris-Shultz et al., 2012). There is currently some question about the designation of phenotypically variable zoysiagrass into different Zoysia species because of the ability of many of these species to readily hybridize (Kimball et al., 2013). For example, 'Crowne' and 'Palisades' are believed to be Z. japonica ´ Z. pacifica (Goudsw.) M. Hotta & S. Kuroki hybrids, while 'Cavalier', 'Diamond', 'Royal', and 'Zorro' may be Z. matrella ´ Z. pacifica hybrids (Engelke, 2000b; Engelke and Anderson, 2003). Using simple sequence repeat (SSR) markers, Kimball et al. (2013) suggested that five of these six cultivars were SSR Allelic Diversity Shifts in Zoysiagrass (Zoysia spp.

Zoysiagrass (Zoysiaspp.) History, Utilization, and Improvement in the United States: A Review

“…Genetic gains of pest and disease tolerance are essential to expand the utilization of zoysiagrass. Analysis of the genetic diversity of currently available cultivars illustrates that plant breeding has not decreased zoysiagrass genetic diversity, and that opportunities exist for increasing diversity, especially through the introduction of alleles from less used germplasm (Moore et al, 2017). Future plant collectors will need to understand that each country has varying regulations in regards to access and dissemination of genetic resources, possibly making these endeavors more difficult than in the past (Moore and Williams, 2011).…”

Variation in tolerance mechanisms to fluazifop-P-butyl among selected zoysiagrass lines

“…However, line 123, another susceptible line, had the same level of radioactivity retained in the treated leaf as the tolerant lines (Table 4). This lack of a clear difference between tolerant and susceptible lines could potentially be attributed to the presence of different mechanisms of fluazifop-P-butyl tolerance among zoysiagrass lines, which is likely a consequence of the high genetic diversity present in zoysiagrass germplasm (Goggin et al 2018;Kimball et al 2012;Moore et al 2017;Patton et al 2017a;Petit et al 2010). Furthermore, it has been reported that multiple nontarget site herbicide resistance mechanisms can be simultaneously present in a single individual, explaining the overall resistant phenotype (Petit et al 2010).…”