Discovery and Characterization of a Turf-type Triploid Seashore Paspalum

Abstract

Seashore paspalum is a salt tolerant, predominately 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 that does not produce segregating seedlings would benefit sod growers and turfgrass managers who demand uniformity for certification and performance. Therefore, an experiment was conducted to create a colchicine-induced polyploid seashore paspalum. One triploid (2n = 3x = 30) genotype (11-TSP-1) was identified 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 reduced and an 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 pollen from several diploid cultivars. The leaf width of 11-TSP-1 was statistically equal to that of the seashore paspalum cultivar 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 with ‘SeaStar’. Future study of the reproductive fertility and more extensive field testing of this genotype should be carried out to determine its turfgrass potential. Chemical names used: 4′, 6-diamidino-2-phenylindole (DAPI), dimethyl sulfoxide (DMSO), iodine-potassium iodide (I2-KI), propidium iodide (PI).