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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Knapp, S. J. Articles by Stroup, W. W. Search for Related Content PubMed Articles by Knapp, S. J. Articles by Stroup, W. W. Agricola Articles by Knapp, S. J. Articles by Stroup, W. W.

Precision of Genetic Variance and Heritability Estimates from Sorghum Populations¹

The emphasis of variance component and heritability estimation experiments has been on point estimation. Minimal attention has been given to confidence interval estimation. Our research was motivated by the limited use of confidence intervals and the importance of interval estimation to the statistical inference process. Our objectives were to evaluate variance component and heritability estimate precision from confidence interval estimate data and to describe the effects of experiment size and point estimate magnitude on interval estimate width. Point and interval estimates (1 - = 0.90) for the family variance component and heritability on a family mean basis were obtained from half-sib, full-sib, or S₁ family selection experiments in four sorghum [Sorghum bicolor (L.) Moench.] populations. Agronomic traits were measured on 200 families per population grown on a Typic Argiudoll soil at Mead, NE, in 1981 and 1982 in a replications-in-incomplete blocks experimental design. Confidence interval estimate widths (widths) were functions of F =(family mean square)/(family x year mean square) M_f/M_fy and tabled F-values determined by degrees of freedom for M_f (df_f) and M_fy (df_fy) and the confidence coefficient (1 - ). Ratios of widths point estimates (ratios) decreased at a decreasing rate as F increased for fixed F-values. Widths and ratios decreased at a decreasing rate as df_f and df_fy increased for fixed F. Ratios for dr_f= d_fy = 190 for variance components were 0.32 for F = 10.0 and 4.27 for F = 1.11, and for heritability were 0.05 for F = 10.0 and 4.05 for F = 1.11. Our data demonstrated the problems of wide interval estimates for large experiments and variation in precision among point estimates for experiments of fixed size.

Key Words: Variance components • Confidence intervals • Standard errors • Recurrent selection • Sorghum bicolor (L.) Moench

² Former graduate research assistant (now assistant professor, Dep. of Crop Science, Oregon State Univ., Corvallis, OR 97331); geneticist (retired), USDA-ARS, Dep. of Agronomy; and associate professor, Biometrics and Information Systems Ctr., Univ. of Nebraska, Lincoln, NE 68583.

Received for publication May 10, 1985.

This article has been cited by other articles:

				R. E. Lorenzana and R. Bernardo Genetic Correlation between Corn Performance in Organic and Conventional Production Systems Crop Sci., May 1, 2008; 48(3): 903 - 910. [Abstract] [Full Text] [PDF]

				D. A. Tabanao and R. Bernardo Genetic Variation in Maize Breeding Populations with Different Numbers of Parents Crop Sci., September 23, 2005; 45(6): 2301 - 2306. [Abstract] [Full Text] [PDF]

				M. Arbelbide and R. Bernardo Random Mating before Selfing in Maize BC1 Populations Crop Sci., March 1, 2004; 44(2): 401 - 404. [Abstract] [Full Text] [PDF]