St. augustinegrass [Stenotaphrum secundatum (Walt.) Kuntz] is a warm-season, perennial grass species commonly used in the turfgrass industry for its superior shade tolerance and stoloniferous growth habit. However, winter survival is a major limiting factor for the species affecting its area of adaptation and marketability, especially in the transition zone of the United States. In addition, the most cold-tolerant cultivars currently available often lack aesthetic characteristics, such as finer leaf texture and shorter internode length that are desirable in the market. Therefore, new st. augustinegrass cultivars with improved winter survival and desirable turf quality are needed for the turfgrass industry in the transitional climatic region of the United States.
Studies have reported significant variability in winter survival and freezing tolerance among present-day cultivars (Kimball et al., 2016a, 2016b; Milla-Lewis et al., 2013; Moseley et al., 2010; Reynolds et al., 2009). Cold hardy cultivar, Raleigh (Bateman, 1980), performs consistently well in the upper range of the species’ geographic limits. However, ‘Raleigh’s’ coarser leaf texture and longer internodes when compared with other st. augustinegrass cultivars as well as other warm-season turfgrasses are often undesirable (Reynolds et al., 2009). Somatic variants and gamma-ray mutants of ‘Raleigh’ were developed in 2004 (Li, 2007). In comparison with ‘Raleigh’, they had improved aesthetic characteristics, but similar to less cold hardiness (Reynolds et al., 2009). On the other hand, available commercial cultivars with good turf quality often have limited cold tolerance. ‘Seville’ (Riordan et al., 1980), a popular cultivar well liked for its semidwarf habit, fine-leaf texture, and dark green color, often exhibits high levels of winterkill (Moseley et al., 2010; Philley et al., 1996; Riordan et al., 1980).
Despite the identification of cold tolerant germplasm, limited progress has been made in breeding for improved winter survival in st. augustinegrass. This is in part due to the complexity of the trait, insufficient genetic knowledge of tolerance components, lack of efficient selection criteria, and limited breeding efforts for this trait. For example, ‘Raleigh’ is still considered an industry standard for cold hardiness in the species 30 years after its release. Previously, Philley et al. (1998) evaluated the inheritance of winter survival in st. augustinegrass with eight diploid genotypes using a diallel analysis. General combining ability was the largest source of variation for winter survival and lethal temperature. The large additive variance indicated that st. augustinegrass should respond to selection (Philley et al., 1998). However, field trials were conducted in Mississippi and may not reflect genotype performance in the upper transition zone. In addition, turf quality was not reported in the study and knowledge of the transferability of turf quality traits from parents to progeny in combination with winter survival in st. augustinegrass is important in the development of new, elite cultivars.
A set of ‘Raleigh’ variants selected for high levels of winter survival as well as improved turf quality (Reynolds et al., 2009) and collections from home lawns in Raleigh, NC, selected for early spring green-up were identified as potential parents for cold tolerant population development. To efficiently use these resources in our breeding program, the objective of this study was to estimate their general and specific combining ability for winter survival and turf quality traits.
Bateman, D.R. 1980 Notice to sod producers and growers relative to the naming and release of the new St. Augustinegrass cultivar ‘Raleigh’. N. C. Ag. Res. Serv., Raleigh, NC
Dennis, E.S., Brettel, R.I.S. & Peacock, W.J. 1987 A tissue culture induced Adhl null mutant of maize results from a single base change Mol. Gen. Genet. 210 181 183
Genovesi, A.D., Jessup, R.W., Engelke, M.C. & Burson, B.L. 2009 Interploid St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] hybrids recovered by embryo rescue In Vitro Cell. Dev. Bio. Plant 45 659 666
Griffing, B. 1956 Concept of general and specific combining ability in relation to diallel crossing systems Austral. J. Bio. Sci. 9 463 493
Guo, H.L., Xue, D.D., Chen, X., Zheng, Y.Q., Wang, Z.Y. & Liu, J.X. 2014 Application of SRAP molecular markers for the identification of zoysiagrass hybrids Acta Hort. 1035 223 232
Kaeppler, S.M. & Phillips, R.L. 1993 Tissue culture induced DNA methylation variation in maize Proc. Natl. Acad. Sci. USA 90 8773 8776
Kenworthy, K.E., Taliaferro, C.M., Carver, B.F., Martin, D.L., Anderson, J.A. & Bell, G.E. 2006 Genetic variation in Cynodon transvaalensis Burtt-Davy Crop Sci. 46 2376 2381
Kimball, J.A., Tuong, T.D., Arellano, C., Livingston, D.P. III & Milla-Lewis, S.R. 2016a Freeze-testing in St. Augustinegrass I: Evaluation methods Eur. J. Agron. (In review)
Kimball, J., Tuong, T.D., Arellano, C., Livingston, D.P. III & Milla-Lewis, S.R. 2016b Freeze-testing in St. Augustinegrass II: Evaluation of acclimation effects Eur. J. Agron. (In review)
Li, R. 2007 St. Augustinegrass improvement for freezing tolerance and semi-dwarf growth habit. North Carolina State Univ., PhD Diss. <http://repository.lib.ncsu.edu/ir/bitstream/1840.16/3275/1/etd.pdf>.
Li, R., Qu, R., Bruneau, A.H. & Livingston, D.P. 2010 Selection for freezing tolerance in St. Augustinegrass through somaclonal variation and germplasm evaluation Plant Breed. 129 417 421
Maier, F.P., Lang, N.S. & Fry, J.D. 1994 Evaluation of an electrolyte leakage technique to predict St. Augustinegrass freezing tolerance HortScience 29 316 318
Milla-Lewis, S.R., Kimball, J.A., Claure, T.E., Tuong, T.D., Arellano, C. & Livingston, D.P. III 2013 Freezing tolerance and the histology of recovering nodes in St. Augustinegrass Intl. Turfgrass Soc. J. 12 523 530
Moseley, D., Patton, A. & Trappe, J. 2010 Winter hardiness of thirty St. Augustinegrass genotypes. Arkansas Turfgrass Report 2010 Ark. Agr. Expt. Stn. Res. Ser. 593 79 84
Mulkey, S.E., Zuleta, M.C., Keebler, J.E., Schaff, J.E. & Milla-Lewis, S.R. 2013 Development and characterization of simple sequence repeat markers for St. Augustinegrass Crop Sci. 54 1 401 412
National Turfgrass Evaluation Program (NTEP) 2012 National turfgrass evaluation program, Beltsville, MD. 22 Aug. 2015. <http://www.ntep.org>.
Philley, H.W., Krans, J., Watson, C., Goately, J., Maddox, V. & Tomaso-Peterson, M. 1996 Turf performance of St. Augustinegrass cultivars in north Mississippi. Miss. Agr. & For. Expt. St. Bul. 1043
Philley, H.W., Watson C.E. Jr, Krans, J.V., Goatley J.M. Jr & Matta, F.B. 1995 Differential thermal analysis of St. Augustinegrass HortScience 30 1388 1389
Philley, H.W., Watson, C.E. Jr, Krans, V., Goatley, J.M., Maddox, V.L. & Tomaso-Peterson, M. 1998 Inheritance of cold tolerance in St. Augustinegrass Crop Sci. 38 451 454
Reynolds, W.C., Li, R., De Silva, K., Bruneau, A.H. & Qu, R. 2009 Field performance of mutant and somaclonal variation lines of St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] Intl. Turfgrass Soc. Res. J. 11 573 582
SAS Inst. Inc 2011 SAS/STAT 9.3 user’s guide. SAS Inst., Inc., Cary, NC
Schwartz, B.M., Kenworthy, K.E., Engelke, M.C., Genovesi, A.D. & Quesenberry, K.H. 2009 Heritability estimates for turfgrass performance and stress response in Zoysia spp Crop Sci. 49 2113 2118
Tan, C., Wu, Y., Taliaferro, C.M., Bell, G.E., Martin, D.L., Smith, M.W. & Moss, J.Q. 2015 Selfing and outcrossing fertility in common bermudagrass under open-pollinating conditions examined by SSR markers Crop Sci. 54 4 1832 1837