Gains through selection for grain yield in a winter wheat breeding program

Abstract

Increased genetic gain for complex traits in plant breeding programs can be achieved through different selection strategies. The objective of this study was to compare potential gains for grain yield in a winter wheat breeding program through estimating response to selection R values across several selection approaches including phenotypic (PS), markerbased (MS), genomic (GS), and a combination of PS and GS (PS+GS). Ten populations of Washington State University (WSU) winter wheat breeding lines including a diversity panel and F5 and double haploid lines evaluated from 2015 to 2019 growing seasons for grain yield in Lind and Pullman, WA, USA were used in the study. Selection was conducted by selecting the top 20% of lines based on observed yield (PS strategy), genomic estimated breeding values (GS), presence of yield "enhancing" alleles of the most significant single nucleotide polymorphism (SNP) markers identified from genome-wide association mapping (MS), and high observed yield and estimated breeding values (PS+GS). Overall, PS compared to other individual selection strategies (MS and GS) showed the highest mean response (R = 0.61) within the same environment. When combined with GS, a 23% improvement in R for yield was observed, indicating that gains could be improved by complementing traditional PS with GS within the same environment. Validating selection strategies in different environments resulted in low to negative R values indicating the effects of genotype-by-environment interactions for grain yield. MS was not successful in terms of R relative to the other selection approaches; using this strategy resulted in a significant (P < 0.05) decrease in response to selection compared with the other approaches. An integrated PS+GS approach could result in optimal genetic gain within the same environment, whereas a PS strategy might be a viable option for grain yield validated in different environments. Altogether, we demonstrated that gains through increased response to selection for yield could be achieved in the WSU winter wheat breeding program by implementing different selection strategies either exclusively or in combination.

Field Screening of Wheat Advanced Lines for Salinity Tolerance

“…The superior response to selection in F6 compared with F7 and F8 was due to higher phenotypic variation in F6 and also greater selection pressure applied from F6 to F7 that led us to exclude the low potential individuals. Similarly, Venuprasad et al [26], Bhutta and Hanif [27], Green et al [28], Akbarpour et al [18], Okechukwu et al [29], Oyiga et al [12], and Lozada et al [30] elucidated the importance of grain yield and its attributed traits in selection through advanced generations under salinity stress.…”

Predicting Fusarium Head Blight Resistance for Advanced Trials in a Soft Red Winter Wheat Breeding Program With Genomic Selection

“…where H 2 was the broad-sense heritability calculated as above, and S is the selection differential, calculated as S = µ Selected − µ Unselected where µ Selected is the mean of the phenotypic data for the top 50% of genotypes selected for genotypes in the ARE generations using either phenotypic selection, NGS, or MTGS, and µ Unselected is the mean of the full unselected population of the genotypes in the ARE generation of the breeding cycle (Falconer and McKay, 1996;Arruda et al, 2016b;Lozada et al, 2020).…”

Single nucleotide polymorphisms reveal genetic diversity in New Mexican chile peppers (Capsicum spp.)

“…A GBS approach includes genomic DNA digestion with restriction enzymes to reduce genome complexity, followed by ligation of barcode adapters, PCR, and sequencing of the amplified DNA [ 14 , 15 ]. Due to its cost-effectiveness and versatility, GBS has been applied for genomics-assisted breeding of important traits on several crops such as rice ( Oryza sativa ) [ 16 ], wheat ( Triticum aestivum ) [ 17 ], soybean ( Glycine max ) [ 18 ], tomato ( Solanum lycopersicum ) [ 19 ], and eggplant ( S. melongena ) [ 20 ], among others. In chile peppers, GBS-derived SNP markers have characterized genetic diversity, genetic stratification, and relatedness among a collection of Spanish landraces, where population structure was related with fruit morphology and geographic origin [ 21 ].…”