A Comparison of Soft Red Winter Wheat F2 Populations, Their F1 Hybrids, and Parents

Abstract

The cost of F1 hybrid soft red winter wheat (Triticum aestivum L.) seed developed with chemical hybridizing agents is from two to three times that of conventionally bred cultivars. Unlike pureline cultivars, it is not possible to save seed from a hybrid wheat crop to produce an identical crop the next year. Costly F1 hybrid seed has led to speculation about using F2 seed for subsequent crop production. The objective of this research was to evaluate this production alternative by comparing F1 hybrids with their respective F2 populations and parents for a number of agronomic traits. Three families (each consisting of an F1, a derived F2, and the original parents) were grown in four environments in Maryland during 1986 and 1987. Treatments were planted in a randomized complete block design in a split-plot arrangement of treatments with families as whole plots and generations as split plots. A significant 8.3% yield decline was found for the F2 populations compared with the F1 hybrids averaged over the environments and families. However, seven of the 12 family-environment combinations had no significant differences for yield between the F1 and F2 populations. High parent heterosis of 4.5% for yield was observed for the hybrids averaged over all families and environments. Only four of 12 family-environment combinations were found to have significant high-parent heterosis. Although significant differences among family members existed for other agronomic traits studied (i.e., spike emergence date, tiller length and variability, test weight, harvest moisture content, and milling and baking quality), none of these differences was judged undesirable for the production of an F2 population. It is concluded that an F2 population, derived from an F1 hybrid wheat, could be successfully used by a farmer for crop production given current hybrid seed costs and market prices. Success is dependent upon the hybrid from which the F2 population is derived and the environment in which it is grown. Furthermore, the low levels of high-parent heterosis suggested that pureline cultivars probably would provide the most economical results for a farmer at the present time.