Estimates of genetic variability and gene action in two maize (Zea mays L.) populations

Han, G C

doi:10.31274/rtd-180813-8667

Cited by 10 publications

(16 citation statements)

References 32 publications

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“…Under these simple conditions, inbred-progeny selection always had the highest expected response to selection (for population per se performance). The assumption of no overdominance was well founded in the best studies of the day suggesting that in fact the average degree of dominance for genes controlling grain yield in maize was less than 1.0 (Gardner and Lonnquist, 1959;Moll et al, 1964;Han and Hallauer, 1989). However, none of the authors promoting inbred-progeny selection considered that pseudo-overdominance could impact selection response in the same way as true overdominance.…”

Section: Inbred-progeny Selection Is Predicted To Be Inferior To Halfmentioning

confidence: 99%

Inbred‐Progeny Selection Is Predicted to Be Inferior to Half‐Sib Selection for Three Maize Populations

Wardyn¹,

Edwards

Lamkey

2009

Crop Science

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Historically, inbred progeny selection has been promoted as an effective means of improving both inbred and outbred performance, and in some cases as being superior to other methods. Advances in theory and new estimates of genotypic covariance components have allowed us to make better predictions of gain from inbred progeny selection than previously available. We developed predicted gain equations using a full model, based on new theory and estimates, and a reduced model, which contained only the additive genetic variance in the numerator, for three maize (Zea mays L.) populations, BS13(S)C0, BSCB1(R)C13, and 3L Comp (HS‐S1)S1 Outbred progeny selection was superior to inbred progeny selection for plant height and grain yield when the response unit was the outbred population. Inbred progeny selection was superior for plant height in both populations and more effective for grain yield in BS13(S)C0 in inbred response units. Negative estimates of the covariance parameter D1 reduced predicted gain for inbred progeny selection in the full model in comparison to the reduced model when D1 was ignored.

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Section: Inbred-progeny Selection Is Predicted To Be Inferior To Halfmentioning

confidence: 99%

Inbred‐Progeny Selection Is Predicted to Be Inferior to Half‐Sib Selection for Three Maize Populations

Wardyn¹,

Edwards

Lamkey

2009

Crop Science

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“…In such context, variance component estimates might more accurately be interpreted as the eff ects of segregating chromosome segments, as opposed to being eff ects of individual alleles. A good example of such an interpretation in the classical literature comes from estimates of dominance variance before and after random mating of F 2 populations (Gardner and Lonnquist, 1959;Moll et al, 1964;Lonnquist, 1980;Han and Hallauer, 1989). Dominance variance was estimated in F 2 populations in linkage disequilibrium and reported as dominance variance without attempts to remove the bias.…”

Section: Design and Estimation Issuesmentioning

confidence: 99%

“…Linkage disquilibrium has been shown to increase following selection (Bulmer, 1971;Hospital and Chevalet, 1996) and drift (Avery and Hill, 1979). In classical studies, it has been shown that random mating of F 2 populations to reduce linkage disequilibrium tends to decrease the dominance variance (Gardner and Lonnquist, 1959;Moll et al, 1964;Lonnquist, 1980;Han and Hallauer, 1989). Conversely, increasing linkage disequilibrim could be expected to increase the magnitude of dominance variance.…”

Section: Role Of Dominancementioning

confidence: 99%

The Genetic Structure of a Maize Population: The Role of Dominance

Wardyn¹,

Edwards

Lamkey³

2007

Crop Science

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The combined effects of dominance and inbreeding on covariances between relatives are still poorly understood in maize (Zea mays L.) populations. Our objectives were to address the following questions: (i) What is the importance of dominance in a maize synthetic? (ii) How does inbreeding affect the genetic variance among individuals in a maize synthetic. (iii) How do the covariance parameters compare between populations? (iv) How does breeding design impact estimators? We estimated covariance components for inbred relatives in the maize synthetic BSCB1(R)C13. Previous estimates of covariance parameters have been used to explain the ineffectiveness of inbred progeny selection in the stiff‐stalk population BS13. We found that the dominance variance was larger than the additive variance for grain yield, whereas the additive variance was larger than the dominance variance for all other traits. Negative estimates of the covariance between additive and homozygous dominance deviations were found for all traits with the exception of traits associated with reproductive maturity, suggesting a negative relationship between inbred and outbred performance. The correlation between genotypic values and breeding values was lower for grain yield than for any other trait. Our results were similar to previous results found in the stiff‐stalk maize population BS13, suggesting similarity in structure among populations.

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“…In an F2 population, the degree of dominance is usually greater then one Gardner et al, 1953; to overdominance. However, random mating the F2 population usually reduces the degree of dominance to less than one (Gardner and Lonnquist, 1959;Moll et al, 1964;Han and Hallauer, 1989) which corresponds to partial or complete dominance. The degree of dominance is of utmost importance to plant breeding programs as it will determine the effect that inbreeding will have on genetic variance.…”

Section: The Role Of Dominance In Inbreedingmentioning

confidence: 99%

The quantitative genetics of a non-stiff-stalk maize (Zea mays L) population

Wardyn

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Estimates of genetic variability and gene action in two maize (Zea mays L.) populations

Cited by 10 publications

References 32 publications

Inbred‐Progeny Selection Is Predicted to Be Inferior to Half‐Sib Selection for Three Maize Populations

Inbred‐Progeny Selection Is Predicted to Be Inferior to Half‐Sib Selection for Three Maize Populations

The Genetic Structure of a Maize Population: The Role of Dominance

The quantitative genetics of a non-stiff-stalk maize (Zea mays L) population

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