Variability Observed in Centipedegrass Grown from 60Co Irradiated Seed1
- R. Dickens,
- W. J. Johnston and
- R. L. Haaland2
Centipedegrass [Eremochloa ophiuroides (Munro) Hack.] has shown limited variability morphology and poor cold tolerance in the 64 years since its introduction into the United States. Variation in morphology and other parameters has been increased in other species by subjecting seed or vegetative parts to ionizing radiation. The purpose of this study was to observe and measure variation in morphology, cold tolerance, and growth habit of centipedegrass grown from irradiated seed. Centipedegrass selections grown from seed exposed to gamma radiation (0 to 80 kR) from a 80Co source were observed for variability in morphology, cold tolerance, and growth habit. No seedling emergence occurred at exposures greater than 40 kR. Irradiated plants had blade widths of 3.7 to 6.8 mm (controls 4.0 to 6.1 mm), blade length of 1.8 to 6.3 cm (controls 2.5 to 4.7 cm), and internode lengths of 0.6 to 4.1 cm (controls 2.0 to 4.1 un). Approximately 7% of the irradiated plants had a dwarfed growth habit, primarily due to shortened internode length. Environmental chamber tests indicated that several irradiated selections were equal or superior in cold tolerance to nonirradiated controls, and to ‘Oklawn’, ‘Tennessee Hardy’, ‘Mississippi 2’, and FC-2. In field studies conducted on a Dothan sandy loam (Plinthic Paleudult), more than 40% of the irradiated plants had an establishment rate from sprigs equal to that of the controls; however, none was superior and 4% were inferior. Variability was also noted in turfgrass color and seedhead production among the irradiated selections. Seven percent produced no seedheads during the 2 years following establishment. Variability observed in these studies indicates the potential use of gamma radiation of seed to improve several turfgrass quality parameters in centipedegrass.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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