HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kwolek, T. F. Articles by Smith, O. S. Search for Related Content PubMed Articles by Kwolek, T. F. Articles by Smith, O. S. Agricola Articles by Kwolek, T. F. Articles by Smith, O. S.

Comparisons of Agronomic Characteristics in C0 and C4 of IAP3BR(M) Random-Mating Grain Sorghum Population¹

Agronomic performance and genetic variability of the random-mating sorghum [Sorghum bicolor (L.) Moench] population IAP3BR(M) were evaluated after four cycles of mass selection for large seed (g/100 seed). Sixty S₁ families chosen at random from both the initial cycle (C0) and the fourth cycle (C4) of the population were grown in 2 yr in central, southern, and northwestern Iowa. Estimates of genotypic variance (²_g) among S₁ families were not significantly different to C0 and C4 for g/l00 seed, seeds/panicle, and plant height. Estimates differed significantly, and they were larger in C4, for grain yield, panicles/plant, and days to midbloom. Heritability estimates for C0 and C4 for each character most often were of similar magnitude. The highest heritabilities were for g/l00 seed, followed by seeds/panicle, grain yield, and panicles/plant. Mass selection was effective for increasing seed size in IAPJBR. Undesirable changes in the means for grain yield, seeds/panicle, and panicles/plant indicated that mass selection for seed size was not effective in improving the overall merit of this population. Means and components of variance, together with estimates of response to selection and correlated response among characters, indicated that SI family testing for grain yield may serve better than mass selection for 100-seed weight for overall improvement of the population beyond the fourth cycle.

Key Words: Sorghum bicolor (L.) Moench • Seed size • Recurrent selection • Mass selection • S₁ family testing

² Former graduate assistant, now maize breeder, Funk Seeds Int., Moms, MN 56267; professor of agronomy, Iowa State Univ., Ames, IA 5001 1; and former research geneticist, USDA-ARS, AR, Ames, IA 5001 1, now research statistician, Pioneer Hi-Bred Int., Johnston, IA 50131.

Received for publication May 31, 1985.