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Modeling of genetic gain for single traits from marker-assisted seedling selection in clonally propagated crops.

Ru S, Hardner C, Carter PA, Evans K, Main D, Peace C - Hortic Res (2016)

Bottom Line: Seedling selection identifies superior seedlings as candidate cultivars based on predicted genetic potential for traits of interest.Both derived and simulated results indicated that marker-based strategies tended to achieve higher genetic gain than phenotypic seedling selection for a trait where the proportion of genotypic variance explained by marker information was greater than the broad-sense heritability.Results from this study provides guidance in optimizing genetic gain from seedling selection for single traits where DNA tests providing marker information are available.

View Article: PubMed Central - PubMed

Affiliation: Department of Horticulture, Washington State University , PO Box 646414, Pullman, WA 99164-6414, USA.

ABSTRACT
Seedling selection identifies superior seedlings as candidate cultivars based on predicted genetic potential for traits of interest. Traditionally, genetic potential is determined by phenotypic evaluation. With the availability of DNA tests for some agronomically important traits, breeders have the opportunity to include DNA information in their seedling selection operations-known as marker-assisted seedling selection. A major challenge in deploying marker-assisted seedling selection in clonally propagated crops is a lack of knowledge in genetic gain achievable from alternative strategies. Existing models based on additive effects considering seed-propagated crops are not directly relevant for seedling selection of clonally propagated crops, as clonal propagation captures all genetic effects, not just additive. This study modeled genetic gain from traditional and various marker-based seedling selection strategies on a single trait basis through analytical derivation and stochastic simulation, based on a generalized seedling selection scheme of clonally propagated crops. Various trait-test scenarios with a range of broad-sense heritability and proportion of genotypic variance explained by DNA markers were simulated for two populations with different segregation patterns. Both derived and simulated results indicated that marker-based strategies tended to achieve higher genetic gain than phenotypic seedling selection for a trait where the proportion of genotypic variance explained by marker information was greater than the broad-sense heritability. Results from this study provides guidance in optimizing genetic gain from seedling selection for single traits where DNA tests providing marker information are available.

No MeSH data available.


A generalized breeding scheme for clonally propagated crops (modified from Grüneberg et al.1).
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Related In: Results  -  Collection

License
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fig1: A generalized breeding scheme for clonally propagated crops (modified from Grüneberg et al.1).

Mentions: Clonal propagation is routinely used for commercial deployment of elite germplasm in many economically important crops, such as root and tuber crops (for example, potato, garlic, sweet potato, yam), fruit crops (for example, apple, banana, citrus, grape, strawberry), ornamentals (for example, chrysanthemum, roses, tulip) and many forest trees.1,2 As an essential way to genetically improve these crops to meet the demand of both consumers and producers, breeding is becoming even more important under a changing environment and a more competitive global market.3,4 Compared with seed propagated crops in which whole plant propagation for replicated breeding trials and commercial deployment relies mainly on sexual reproduction via meiosis, breeding of clonally propagated crops combines both sexual and asexual reproduction (Figure 1). Genetic variation in seedling generations is typically provided via sexual reproduction by crossing parents with complementary features. Successive rounds of performance evaluation and selection are then used to identify offspring with increasingly promising genetic potential for consideration as candidate cultivars (Figure 1). Selected individuals are clonally propagated for subsequent replicated trials and, if publicly released, are clonally propagated on a larger scale for commercial production. In this way, dominance and epistatic genetic action, in addition to additive effects, can be captured in selected individuals for contribution to superior commercial performance.5,6


Modeling of genetic gain for single traits from marker-assisted seedling selection in clonally propagated crops.

Ru S, Hardner C, Carter PA, Evans K, Main D, Peace C - Hortic Res (2016)

A generalized breeding scheme for clonally propagated crops (modified from Grüneberg et al.1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837533&req=5

fig1: A generalized breeding scheme for clonally propagated crops (modified from Grüneberg et al.1).
Mentions: Clonal propagation is routinely used for commercial deployment of elite germplasm in many economically important crops, such as root and tuber crops (for example, potato, garlic, sweet potato, yam), fruit crops (for example, apple, banana, citrus, grape, strawberry), ornamentals (for example, chrysanthemum, roses, tulip) and many forest trees.1,2 As an essential way to genetically improve these crops to meet the demand of both consumers and producers, breeding is becoming even more important under a changing environment and a more competitive global market.3,4 Compared with seed propagated crops in which whole plant propagation for replicated breeding trials and commercial deployment relies mainly on sexual reproduction via meiosis, breeding of clonally propagated crops combines both sexual and asexual reproduction (Figure 1). Genetic variation in seedling generations is typically provided via sexual reproduction by crossing parents with complementary features. Successive rounds of performance evaluation and selection are then used to identify offspring with increasingly promising genetic potential for consideration as candidate cultivars (Figure 1). Selected individuals are clonally propagated for subsequent replicated trials and, if publicly released, are clonally propagated on a larger scale for commercial production. In this way, dominance and epistatic genetic action, in addition to additive effects, can be captured in selected individuals for contribution to superior commercial performance.5,6

Bottom Line: Seedling selection identifies superior seedlings as candidate cultivars based on predicted genetic potential for traits of interest.Both derived and simulated results indicated that marker-based strategies tended to achieve higher genetic gain than phenotypic seedling selection for a trait where the proportion of genotypic variance explained by marker information was greater than the broad-sense heritability.Results from this study provides guidance in optimizing genetic gain from seedling selection for single traits where DNA tests providing marker information are available.

View Article: PubMed Central - PubMed

Affiliation: Department of Horticulture, Washington State University , PO Box 646414, Pullman, WA 99164-6414, USA.

ABSTRACT
Seedling selection identifies superior seedlings as candidate cultivars based on predicted genetic potential for traits of interest. Traditionally, genetic potential is determined by phenotypic evaluation. With the availability of DNA tests for some agronomically important traits, breeders have the opportunity to include DNA information in their seedling selection operations-known as marker-assisted seedling selection. A major challenge in deploying marker-assisted seedling selection in clonally propagated crops is a lack of knowledge in genetic gain achievable from alternative strategies. Existing models based on additive effects considering seed-propagated crops are not directly relevant for seedling selection of clonally propagated crops, as clonal propagation captures all genetic effects, not just additive. This study modeled genetic gain from traditional and various marker-based seedling selection strategies on a single trait basis through analytical derivation and stochastic simulation, based on a generalized seedling selection scheme of clonally propagated crops. Various trait-test scenarios with a range of broad-sense heritability and proportion of genotypic variance explained by DNA markers were simulated for two populations with different segregation patterns. Both derived and simulated results indicated that marker-based strategies tended to achieve higher genetic gain than phenotypic seedling selection for a trait where the proportion of genotypic variance explained by marker information was greater than the broad-sense heritability. Results from this study provides guidance in optimizing genetic gain from seedling selection for single traits where DNA tests providing marker information are available.

No MeSH data available.