Recurrent Selection for Lodging Susceptibility and Resistance in Corn
1972
Thompson, D. L.
Recurrent selection was practiced for two corn synthetics, Syn 8 and Syn 9 (Zea mays L.), for lodging susceptibility (6 cycles) and lodging resistance (7 cycles) counting erect plants at maturity. Selection progress was evaluated using crosses between comparable cycles of the two synthetics and determining changes for the following traits: erect plants; ratings for root clump, rind puncture, and stalk rot; stem section dry weight, crushing strength, rind thickness, specific gravity, water content, and pith ratings; and yield and other agronomic characters. Compared with the cross of the original synthetics as 100%, the last cycle for susceptibility (cycle 6) had 28% as many erect plants and the last cycle for resistance (cycle 7) had 228% as many. Observed means for these comparisons were 40.3, 11.3, and 91.9% erect plants, respectively. All possible simple correlation coefficients among the stalk and root quality traits were significant at the 1% level except for pith ratings. The use of a single selection criterion (erect plants) insured that associated changes in other traits were not confounded by other conscious selection.
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