Relative changes in genetic variability and correlations in an early-maturing maize population during recurrent selection
Four cycles of S 1 family recurrent selection to improve grain yield and resistance to Striga hermonthica have been completed in TZE-Y Pop STR C 0. In order to determine whether or not to continue with the recurrent scheme, it was desirable to evaluate the amount of residual genetic variance and ass...
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Published in | Theoretical and applied genetics Vol. 125; no. 6; pp. 1289 - 1301 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer-Verlag
01.10.2012
Springer Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Four cycles of S
1
family recurrent selection to improve grain yield and resistance to
Striga hermonthica
have been completed in TZE-Y Pop STR C
0.
In order to determine whether or not to continue with the recurrent scheme, it was desirable to evaluate the amount of residual genetic variance and associated parameters in the population. The objective of this study was to characterize the relative changes in the levels of the genetic variances, heritability estimates and genetic correlation coefficients, and to predict future gains from selection for grain yield,
Striga
resistance and other agronomic traits. Fifty S
1
families, derived from each cycle, were evaluated under
Striga
-infested and
Striga
-free conditions at Mokwa, Ikenne and Abuja, Nigeria, in 2005 and 2007. Under
Striga
infestation, genetic variances for grain yield, days to anthesis, plant height and
Striga
damage generally increased in the advanced cycles of selection. In contrast, the genetic variances for days to silk, anthesis–silking interval, ears per plant, ear aspect and number of emerged
Striga
plants decreased with selection. The advanced cycles of selection significantly out-yielded the original cycle in both research environments. Heritabilities for grain yield
, Striga
damage and number of emerged
Striga
plants were significantly greater than zero. The realized gains from selection for grain yield under
Striga
infestation (52 kg ha
−1
cycle
−1
) and
Striga
-free conditions (130 kg ha
−1
cycle
−1
) were remarkably lower than the predicted gains (350 and 250 kg ha
−1
cycle
−1
, respectively). Adequate genetic variability exists in cycle 4 of the scheme to ensure future gains from selection. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0040-5752 1432-2242 |
DOI: | 10.1007/s00122-012-1913-8 |