Development, Linkage Mapping, and Use of Microsatellites in Bermudagrass

Abstract

<jats:p>Genetic linkage maps of bermudagrass (<jats:italic>Cynodon</jats:italic> spp.) species using 118 triploid individuals derived from a cross of T89 [<jats:italic>C. dactylon</jats:italic> (2n = 4x = 36)] and T574 [<jats:italic>C. transvaalensis</jats:italic> (2n = 2x = 18)] were enriched with expressed sequence tags-derived simple sequence repeat (EST-SSR) markers. Primers were developed from 53 ESTs containing SSRs producing 75 segregating markers from which 28 could be mapped to the T89 and T574 genetic maps. With the addition of previously generated marker data, 26 T89 linkage groups and eight T574 linkage groups were formed using a log-of-odds (LOD) value of 4.0. The T89 and T574 linkage maps spanned 1055 cM and 311.1 cM and include 125 and 36 single-dose amplified fragments (SDAFs), respectively. Many of the SDAFs displayed disomic segregation and thus T89 may be a segmental allotetraploid or an allotetraploid. The additional EST-SSR markers add value to the maps by increasing marker density and provide markers that can be easily transferred to other bermudagrass populations. Furthermore, EST-SSRs can be immediately used to assess genetic diversity, identify non-mutated cultivars of bermudagrass, confirm pedigrees, and differentiate contaminants from cultivars derived from ‘Tifgreen’.</jats:p>

The genetic and phenotypic variability of interspecific hybrid bermudagrasses (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy) used on golf course putting greens

“…TifEagle was one of 48 putative mutants resulting from the irradiation of ‘Tifway II’ with 70 grays (7000 rads) of cobalt-60 gamma radiation (Hanna and Elsner 1999). While TifEagle was reported to be derived from Tifway II (Hanna and Elsner 1999); Harris-Shultz et al (2010) and Zhang et al (1999), both suggested that TifEagle may have been derived from Tifgreen (or a Tifgreen related plant) due to the high dissimilarity coefficients reported between TifEagle and Tifway II using amplified fragment length polymorphism (AFLP) methodology. Findings of Capo-chichi et al (2005) and Chen et al (2009) further support this assertion in that both research teams reported a high degree of genetic similarity between TifEagle and Tifgreen.…”

“…Identical alleles were found for the six cultivars, indicating that they were all derived from Tifgreen and could not be differentiated from one another (Harris-Shultz et al 2010). Wang et al (2010) reported similar results to Harris-Shultz et al (2010) using simple sequence repeat (SSR) markers, which grouped Tifgreen, Tifdwarf, TifEagle, Floradwarf, MS-Supreme, Champion Dwarf, and MiniVerde into a single mutation family.…”

“…Identical alleles were found for the six cultivars, indicating that they were all derived from Tifgreen and could not be differentiated from one another (Harris-Shultz et al 2010). Wang et al (2010) reported similar results to Harris-Shultz et al (2010) using simple sequence repeat (SSR) markers, which grouped Tifgreen, Tifdwarf, TifEagle, Floradwarf, MS-Supreme, Champion Dwarf, and MiniVerde into a single mutation family. The SSR markers used by Wang et al (2010) identified 22 cultivars derived via the traditional breeding; however, mutation-derived cultivars (such as TifEagle, Floradwarf, MS-Supreme, Champion Dwarf, and MiniVerde) were genetically indistinguishable from each other (Fig.…”

“…c Figure reproduced with permission from Springer and Zhang et al (1999). d Figure reproduced with permission from the Journal of American Society of Horticultural Sciences and Harris-Shultz et al (2010). e Figure reproduced with permission from Crop Science and Wang et al (2010)…”

“…Figure 2 shows five dendrograms generated from genetic diversity research conducted by Capo-chichi et al (2005), Harris-Shultz et al (2010), Kamps et al (2011), Wang et al (2010), and Zhang et al (1999). These dendrograms demonstrate that not all Tifgreen and Tifgreen-derived cultivars can be genetically distinguished from one another, despite variable success SSR markers reported by Harris-Shultz et al (2011) and Kamps et al (2011).…”