Biometrical analysis of alternative plot types for selection in rye

Abstract

Maximizing the efficiency of selection for yield and baking quality of winter rye (Secale cereale) requires reliable knowledge of the pertinent population parameters. Estimates of variances, heritabilities and genetic correlations from (1) large (~ 5 m²) drilled (LD) plots, (2) micro drilled (MD) plots, and (3) one-row plots of 4 spaced plants (SP) are reported. Thirty-eight single crosses of rye were grown at 2 locations for 2 years in LD, MD and SP plots replicated 2, 4 and 6 times, respectively. Genotypic differences were significant in all plot types for all agronomic and quality traits, although estimates of genetic variances were smaller in LD than MD or SP plots for grain yield, 32-spike weight and grains/spike. Heritabilities on an entry mean basis (0.62 to 0.95) were similar among plot types, but on a single plot basis estimates were lower for SP than for MD or LD plots. Genetic correlations were high between all 3 plot types, with correlations between LD and SP plots being approximately 1.0 for falling number, 1000-grain weight, and flowering date, 0.90 for grain yield, grains/spike, test weight and height, and 0.70 for tiller number. Based on the high heritabilities achieved in small plots and the close agreement between MD- or SP- with LD-plot performance it was concluded that greater use should be made of small plot types when selecting for yield and quality in winter rye