Selection for Early Flowering in Corn: 10 Late Synthetics
1985
Troyer, A. F. | Larkins, J. R.
The purpose of this study was to determine if selection for earliness and better stalk quality in late synthetics would be effective. Ten corn (Zea mays L.) synthetics adapted to southern Iowa and northern Missouri were grown at high plant density in southern Minnesota near Mankato. The earliest 5% to flower were selected for 11 generations and selection for better stalk quality was also enforced, during the last six cycles. The original populations and the 11 selected cycles were then compared in performance trials at moderate plant density over 3 years. Selection effect per cycle for 11 cyclea averaged: l I Celsius heat units (about 1 day) less to pollen shed; 1.4 points less grain moisture; 23 mm less plant height; 0.3 days less silk delay; 167 kg ha∕¹ (5%) more yle|d; and 0.5% more broken stalks. Comparing cycles 0 to 5 (selection for early flowering only) with cycles 6 to 11 (selection for early flowering plus better stalk quality) showed that effective selection for earlier flowering and associated less grain moisture continued in cycles 6 to 11, but at a decreased rate. Gain from selectsion against silk delay was reduced in cycles 6 to 11 because near‐optimum performance had been attained. Selection for better stalk quality was effective in cycles 6 to 11, and the number of broken stalks at harvest was stabilized. We recommend selection for early flowering with or without stalk quality selection to make. late, exotic materials earlier, thereby enhancing their potential contribution of useful genetic diversity to the U.S. Corn Bellt.
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