The Evaluation Of Growth,Cold Tolerance And Turf Characteristics Of Three Different Ecotypes Of Centipedegrass (Remochloa Ophiuroides(Mun Ro.)HaCk.)

Centipedegrass (Eremochloa ophiuroides) is an important warm-season turfgrass variety in the world, belonging to Eremochloa Buese Poaceae (C4) plant families, which was originated from south and central China, possessed of excellent stress resistance and low maintenance level, but was sensitive to low temperature. Nanjing and Zhenjiang area in Jiangsu province is hilly region, and the water and heat distribution is significantly different influenced by Yangtze river. Therefore it possesed various ecotypes of centipedegrass which provided abundant germplasm resource for the breeding of good centipedegrass varieties. In this paper, three ecotypes of centipedegrass originated from Pukou Nanjing and Zhongshan Nanjing Jiangsu province and Xinyi Guangdong province were studied systematically on the growth, cold tolerance and turf characteristics. The purpose of present study was to investigate the differences among different centipedegrass germplasm resources, so as to provide suitable germplasm resources for further breeding program. The main results were as follows:1. Xinyi centipedegrass grew fast, formed a highly dense leafy sward in the end of the first year. Pukou and Zhongshan centipedegrass grew relatively slowly and the coverage rates were lower than Xiny in the end of the first growth season. The morphological characteristics of centipedegrass were significantly different among upright leaves and creeping leaves. The stolons of Xinyi centipedegrass were slender, Pukou centipedegrass were stubby, and Zhongshan centipedegrass were the medium of the two above. The stolons colour of Xinyi and Zhongshan centipedegrass was green-red and Pukou centipedegrass was green-yellow. The phenological periods of three ecotypes were different. Xinyi centipedegrass had no sexually reproduction in Nanjing area, turning yellow early and turning green late. Zhongshan centipedegrass headed and bloomed in June and its seeds maturated in August. Pukou centipedegrass headed7days later than Zhongshan and its flowering phase last until the end of Septembe and seeds maturated in October, and it turned yellow the latest and turned green the earliest among the three varieties. Xinyi centipedegrass was barrenness. The anthers color of Zhongshan centipedegrass was purple-red while Pukou centipedegrass was yellow-white. There were significant differences in spikes density, the number of spikelets per spike, fertile tillers height, inflorescence length and the seedset rate between the two ecotypes (P<0.05). The theoretical seed yield of Pukou centipedegrass was higher than that of Zhongshan centipedegrass.2. During natural temperature declining, the leaf chlorophyll content of Pukou centipedegrass was the highest among the three ecotypes. Its electrolyte leakage and MDA content increased slightly but water soluble carbohydrates content increased sharply3.3times. Water soluble protein content and SOD activities decreased firstly and then increased. Its over wintering rates was86%, the highest among the three. The overwintering rate of Zhongshan centipedegrass was76.5%. The leaf chlorophyll content of Xinyi centipedegrass was the lowest of all varieties. Its electrolyte leakage and MDA content increased sharply whereas water soluble sugar content increased evevly1.8times. Its soluble protein content and SOD activities were low. As a result, it turned yellow earliest and the overwintering rate was only6.5%. Pukou centipedegrass had the longest green period of255days, zhongshan was242days, while Xinyi centipedegrass was217days under field observation. The cold tolerance of three ecotypes of centipedegrass obtained by fuzzy mathematical subordination function method was:Pukou centipedegrass> Zhongshan centipedegrass> Xinyi centipedegrass. Those results were coordinated with field observation.3. Under artificial low temperature stress, the physiological and biochemieal indexes of the three ecotypes of centipedegrass changed in the same tendency, but there were differences in metirals. Compared with all the physiological indexes which transformed by fuzzy mathematical subordination function method, the electrolyte leakage and MDA content of Pukou centipedegrass was slow, while the water soluble sugar content and SOD activities were high. The chlorophyll content and water soluble protein content of Zhongshan centipedegrass were high. The electrolyte leakage and MDA content of Xinyi centipedegrass were high, whereas its chlorophyll content, water soluble sugar content, soluble protein content and SOD activities were low. The cold tolerance of three ecotypes of centipedegrass was:Pukou centipedegrass> Zhongshan centipedegrass> Xinyi centipedegrass.4. The turf characteristics of three centipedegrass ecotypes were evaluated by the comprehensive assessment in field plot test. The results indicated:evaluation score of Pukou centipedegrass was the highest and the turf quality was the best in the three ecotypes. Zhongshan centipedegrass was inferior to Pukou centipedegrass. Both of the two ecotypes were suitable for recreational turf. The scores of coverage rates, uniformity and density of XinYi centipedegrass were low, as a result of poorest turf quality performance. All kinds of turf applicability assessment of XinYi centipedegrass were the lowest in the three ecotypes, which were mainly due to its low over winter survival rate.