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 Wells, W. C. Articles by Kofoid, K. D. Search for Related Content PubMed Articles by Wells, W. C. Articles by Kofoid, K. D. Agricola Articles by Wells, W. C. Articles by Kofoid, K. D.

Selection Indices to Improve an Intermating Population of Spring Wheat¹

The intermating population of spring wheat (Triticum aestivum L.) NDPl was created to be a source of both cultivars and parental lines for future breeding populations. The objective of this study was to predict the relative merits of four types of selection indices for improving NDPl, and to predict the gain in efficiency of selection from using information on secondary characters in the calculation of index weights. Smith-Hazel, base, and desired gain indices were constructed to increase yield and percent protein and decrease plant height. Restricted selection indices were constructed to increase yield and eliminate undesirable correlated responses in percent protein and plant height. Comparisons were made based upon predicted responses from S₁ family selection. Estimates of the population parameters were derived from 200 S₁ families grown in two replications in the field in 1981 and 1982. Broad sense heritabilities for all measured characters were high. Genotypic and phenotypic covariances between yield and percent protein were negative, while covariances between these two characters and the characters plant height and kernel weight were positive. The Smith-Hazel index maximized predicted gains in the aggregate genotype, with a predicted increase in yield of 9.6%, a decrease in plant height of 0.3%, and an increase in percent protein of 1.1%. Similar responses were predicted for the base and restricted selection indices. A 2.7% increase in yield and percent protein, and a 2.7% decrease in plant height were predicted for selection based upon a desired gain index. The inclusion of information on the secondary characters (kernel weight, spike length, kernels per spike, and spikelets per spike) in indices did not appreciably increase their predicted efficiencies. Indices designed to improve the aggregate genotype should be effective in developing NDPl as a source of high yielding conventional height lines. If high yielding, high protein semidwarf lines are desired, a desired gain index should be considered for improving NDP1.

Key Words: Triticum aestivum L. • S₁ family selection • Genotypic correlations • Smith-Hazel index • Desired gain index

² Former graduate research assistant (currently, postgraduate research geneticist, Dep. of Botany and Plant Sci., Univ. of California, Riverside, CA 9252 I), and associate professor, respectively, Dep. of Agronomy, North Dakota State Univ., Fargo, ND 58105.

Received for publication March 4, 1985.

This article has been cited by other articles:

				A. Collaku and S. A. Harrison Heritability of Waterlogging Tolerance in Wheat Crop Sci., February 23, 2005; 45(2): 722 - 727. [Abstract] [Full Text] [PDF]

				M. J. Giroux, L. Talbert, D. K. Habernicht, S. Lanning, A. Hemphill, and J. M. Martin Association of Puroindoline Sequence Type and Grain Hardness in Hard Red Spring Wheat Crop Sci., March 1, 2000; 40(2): 370 - 374. [Abstract] [Full Text]