Genetic Variation and Correlation of Agronomic Traits in Diploid Rhodesgrass (Chloris gayana Kunth) Populations

摘要

We studied variation in and heritability of agronomic traits and correlations among these traits in populations of diploid rhodesgrass (Chloris gayana Kunlh) in 2 experiments as a basis for future rhodesgrass breeding Significant differences existed among populations for all traits evaluated in row-planted plants (experiment 1), and for all traits except plant height at the third cut in space-planted plants (experiment 2) In rows broad-sense her it-ability estimates were moderately high for seedlingvigor in spring and total fresh yield. In spaced plants, broad-sense her liability estimates were moderate for head number, stolon number, plant growth habit, percentage of heading plants and total fresh yield. The relatively high genetic coefficients ofvariation (GCV) and moderately high heritability estimates found for seedling vigor in spring and total fresh yield indicate that selection for these traits would be effective in these diploid populations. Total fresh yield was significantly positivelycorrelated with seedling vigor in spring in rows and with fresh yield at the second cut of rows and spaced plants but it was significantly negatively correlated with head number in rows and percentage of heading plants which indicate the stage of maturity, in spaced plants. The strong positive correlations between total fresh yield and fresh yield at the second cut in the 2 experiments indicate that fresh yield at the second cut can be used as a selection index for identifying high-fresh-yield genotypesor populations in the development of superior cultivars of diploid rhodesgrass.