Germplasm Resource Evaluation Of Different Populations Of Wild Poa Pratensis In Shanxi

The agronomic traits, turf quality and drought resistance (seedling period) of wild Poa pratensis in ShanXi province were studied by collection, cultivation and domestication in order to evaluate the differences among different populations of wild Poa pratensis. The purpose of this experiment was to provide a theoretical basis for utilization of wild germplasm resources and for screening local excellent Poa pratensis. The results showed as following:(1) The diversity analysis of12agronomic traits of49wild Poa pratensis germplasm resources showed that the agronomic traits had extremely significantly difference among populations of wild Poa pratensis (P<0.01). The variation coefficient of agronomic traits were from11.92%to72.73%. According to principal component analysis, the cumulative contribution of seven principle elements was86.91%, which including most informations of agronomic traits. These germplasm resources can be integrated evaluation by this information above.(2) Different wild populations of Poa pratensis were clustered into four groups based on the principal component analysis. The populations of Ⅱ and Ⅲ groups were better, and could be used as the key selection object in the future.(3) The turf quality of twenty wild germplasm resources which had been selected from forty-nine populations were studied in contrast with Aimyth. The seeding stage and turf forming date were observed and growth rate, regeneration rate, coverage, density, texture, color, uniformity, over winter rate of twenty different populations Poa pratensis in Shanxi were measured to comprehensively evaluate their turf quality. The results showed that the growth rate and turf quality of different wild Poa pratensis were significantly difference. The germinating date and maturate time of QS-45and HY-05populations of wild Poa pratensis were shorter than other populations. The populations of QS-45and HY-05which had the best integrated turf quality could be used as lawn grass and were the best choice for popularization and application.(4) The drought resistance (seedling period) of thirty wild germplasm resources which had been selected from forty-nine populations were studied in contract with Midnight. Under drought stress, seedling survival rates had different performance among populations of wild Poa pratensis, but the relative growth rates (RGR) were obviously decreased; The total biomass decreased, and the root ratio of shoot increased. After rewatering, growth characteristics have recovered, but did not reach the control level. There were significant differences among different populations (P<0.05).(5) Under drought stress, all physiological indexes in leaves or roots of different populations of wild Poa pratensis changed consistently, but there were disparities about changed range among different populations. The contents of praline (Pro), soluble protein (SP), soluble sugar (SS) and malondialdehyde (MDA) increased after21d drought stress, whereas relative growth rate (RWC), activity of SOD and CAT declined. The changes of leaves were obviously greater than roots. After rewatering, all the indexes were rehabilitated to some degree, but did not reach the control level. There were significant differences among different populations (P<0.05).(6) Drought resistance of different populations of Poa pratensis was evaluated with subordination function method. The results showed that all the Poa pratensis were divided into two kinds, class II were the medium drought-resistant including sixteen populations, and the other fifteen populations belonging to class Ⅲ had weaker drought resistance. The largest membership value of population QS-45wild Poa pratensis was0.738. The drought resistance of QS-45was better than that of Midnight.