SELECTION FOR TOLERANCE TO BOTH DROUGHT AND FROST AMONG A LARGE NUMBER OF BERMUDAGRASS (CYNODON SPP.) ECOTYPES COLLECTED FROM DIFFERENT CLIMATIC ZONES

摘要

As a warm-season grass,bermudagrass (Cynodon spp.) has been widely used as turf and/or pasture in most parts of the world; however,drought and frost are two of the most important abiotic factors that can reduce growth and performance.Drought and frost tolerance of 432 bermudagrass ecotypes collected from 4 climatic zones of Australia with 5 different ranges of Potential Frost Days (PFD) were assessed in a field experiment in Southeast Queensland,Australia.Turf quality (TQ) and leaf death were scored after a drought period in 2010 and a frost period in 2011,respectively.Using cluster analysis,all the genotypes were classified into 10 groups based on TQ and leaf death ratings scored in both environments.Group 1 included 45 genotypes which were considered as drought and frost tolerant had higher average TQ and lower average leaf death than other groups.No commercial cultivars were placed in this group.The regions that provided the highest frequency of genotypes in the drought and frost tolerant group were the Mediterranean climatic zone and the regions with 30-40 and 40-50 PFD.