Graduation date: 1967Morphological changes in five clonally propagated genotypes\ud of Agrostis L. resulting from variations in environment were\ud studied in six natural environments extending from southern Oregon\ud to northern British Columbia. These same clones were also subjected\ud to four different cutting heights in turf plots. In addition to\ud the field experiments, they were also studied in growth chambers\ud using four different combinations of day and night temperatures.\ud Tiller number, plant diameter, leaf width, leaf length, aerial\ud branching, rhizome number, rhizome length, nodes per rhizome,\ud stolon number, stolon length and the number of stolon nodes were\ud the morphological characteristics studied.\ud Consistent morphological differences indicated that the five\ud clones do not belong to the same species. Detailed taxonomic study of the population from which these clones were selected is\ud warranted.\ud The five clones varied in their capacity to tiller. The density\ud of tillers depended both upon environment during the time of tiller\ud development and clonal genetic differences. Experimental genotypes\ud differed greatly in their susceptibility to Fusarium sp., therefore\ud causing some of the differences in tiller density during the spring\ud observation time. The genotypes reacted differently to cutting\ud height defoliation during different seasons. They also reacted\ud differently to temperature, day length and light intensity.\ud The five genotypes each had different leaf widths and leaf\ud lengths when grown in similar environments. Increased light intensity\ud and day length increased the leaf width at locations where\ud the temperature had not affected the development of leaves and\ud initiation of leaf primordia. Within one temperature combination\ud one genotype produced the narrowest leaves and the widest leaves\ud were produced by the other four. The length of leaves depended\ud mainly upon the genotype. No correlation between leaf width and\ud length was observed.\ud Aerial branching occurred in times when the dominance of\ud the apical bud was removed and the lateral buds developed. Correlation\ud between tillering and aerial branching within clones was\ud observed.\ud Clonal differences accounted for most of the variation in\ud rhizome number. Rhizome length was influenced by clones,\ud environment and the clone x environment interaction. No correlation\ud existed between the clones ability to form tillers and rhizomes.\ud The clones formed most stolons in the fall after the sterile\ud shoots had been formed. Short days and lower light intensity in\ud the fall combined with low night temperatures were the environmental\ud factors which promoted the formation of stolons. The\ud ability of clones to form stolons was not related to their ability to\ud form rhizomes or tillers
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.