Location: Crop Genetics and Breeding ResearchTitle: Discovery and characterization of a turf-type triploid seashore paspalum Author
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2013
Publication Date: 1/6/2014
Citation: Schwartz, B.M., Contreras, R.N., Harris-Shultz, K.R., Heckart, D.L., Peake, J.B., Raymer, P.L. 2014. Discovery and characterization of a turf-type triploid seashore paspalum. HortScience. 48:1424:1427. Interpretive Summary: Seashore paspalum is a salt tolerant turfgrass and is used in areas with salt-affected water or soils. A majority of the available cultivars are vegetatively propagated but are fertile which allows cross-fertility and thus the production of seedlings not of the parental genotype. These seedlings have characteristics different than their parent and thus visual uniformity is affected. Thus a need exists for the production of sterile seashore paspalum cultivars. In this study a triploid bermudagrass plant, 11-TSP-1, was obtained by ploidy manipulation using the chemical colchicine. Unlike other naturally occurring seashore paspalum polyploids seen, 11-TSP-1 has fine leaves with a dark green color. Currently this line is being evaluated for its turfgrass potential.
Technical Abstract: Seashore paspalum (Paspalum vaginatum Swartz) is a salt tolerant, predominantly diploid (2n = 2x = 20) species that is well adapted to coastal regions in tropical and subtropical environments. Because a majority of the available cultivars are propagated vegetatively and most genotypes are cross-fertile, a sterile cultivar which does not produce segregating seedlings would benefit sod growers and turfgrass managers who demand uniformity for certification and performance. Therefore, three independent laboratory and glasshouse experiments were conducted during 2009, 2010, and 2011 to create a colchicine-induced polyploid seashore paspalum, and ultimately, to develop a sterile form. Percent germination of seed was similar in all three experiments, varying from 14.2% (2011), 15.3% (2009), to 18.1 % (2010). Seedling ploidy levels were determined using flow cytometry and verified with chromosome counts. One triploid (2n = 3x = 30) genotype (11-TSP-1) was identified from the 2010 test and remains stable. Although there is a possibility that this event was triggered by the colchicine treatment, a more likely explanation is that it resulted from the union of a normal and unreduced gamete. Pollen shed was observed from 11-TSP-1 in 2011, but individual pollen grains stained with iodine-potassium iodide were irregularly shaped and typically had lower starch content than several diploid cultivars. The leaf width of 11-TSP-1 was statistically equal to the seashore paspalum cultivars ‘Platinum TE’ and ‘SeaStar’, indicating its potential for use as a fine turf. 11-TSP-1 had both superior visual color and a dark green color index when compared to Platinum TE and SeaStar. Future study of the reproductive fertility and more extensive field testing of this genotype should be carried out to determine its breeding value and turfgrass potential.