Relation Between S2 and Later Generation Testcrosses of Two Corn Populations

Authors

S. M. Lile, Iowa State University
A. R. Hallauer, Iowa State UniverstiyFollow

Document Type

Research

Keywords

Zea mays L.; corn breeding; combining ability; inbred lines

Abstract

Determination of the relative combining abilities of corn (Zea mays L.) inbred lines is an important feature of applied corn breeding programs. Combining ability is measured by the relative performance of a line in testcrosses to one or more testers. Inbred lines from BS13(S2)Cl and BSCB1(R)C7 corn populations were evaluated at the S₂ and later generations of inbreeding. Intense selection was practiced among and within lines during inbreeding to develop the S₅-equivalent and S₈ generation lines. The objective of this study was to determine if the combining ability of lines in early generations (S₂) of inbreeding was similar to the combining ability of lines at later generations of inbreeding. Testcross trials were conducted at four Iowa locations. Genetic correlations between the S₂ and later generation testcrosses for gram yield were 0.9.7 for BS13(S)Cl and 0.86 for BSCB1(R)C7. The S₂ testcross data were highly predictive of S₈ testcross data, suggesting that early testing was effective in discriminating among these lines for relative combining abilities at later generations of inbreeding.

Publication Date

March 1994

Journal Title

Journal of the Iowa Academy of Science

Volume

101

Issue

1

First Page

19

Last Page

23

Copyright

© Copyright 1994 by the Iowa Academy of Science, Inc.

Language

EN

File Format

application/pdf

Recommended Citation

Lile, S. M. and Hallauer, A. R. (1994) "Relation Between S2 and Later Generation Testcrosses of Two Corn Populations," Journal of the Iowa Academy of Science: JIAS, 101(1), 19-23.
Available at: https://scholarworks.uni.edu/jias/vol101/iss1/6