Genomic selection outperforms marker assisted selection for grain yield and physiological traits in a maize doubled haploid population across water treatments

To increase genetic gain for tolerance to drought, we aimed to identify environmentally stable QTL in per se and testcross combination under well-watered (WW) and drought stressed (DS) conditions and evaluate the possible deployment of QTL using marker assisted and/or genomic selection (QTL/GS-MAS). A total of 169 doubled haploid lines derived from the cross between CML495 and LPSC7F64 and 190 testcrosses (tester CML494) were evaluated in a total of 11 treatment-by-population combinations under WW and DS conditions. In response to DS, grain yield (GY) and plant height (PHT) were reduced while time to anthesis and the anthesis silking interval (ASI) increased for both lines and hybrids. Forty-eight QTL were detected for a total of nine traits. The allele derived from CML495 generally increased trait values for anthesis, ASI, PHT, the normalized difference vegetative index (NDVI) and the green leaf area duration (GLAD; a composite trait of NDVI, PHT and senescence) while it reduced trait values for leaf rolling and senescence. The LOD scores for all detected QTL ranged from2.0 to 7.2 explaining 4.4 to 19.4%of the observed phenotypic variance with R2 ranging from0 (GY, DS, lines) to 37.3%(PHT, WW, lines). Prediction accuracy of the model used for genomic selection was generally higher than phenotypic variance explained by the sumof QTL for individual traits indicative of the polygenic control of traits evaluated here. We therefore propose to use QTL-MAS in forward breeding to enrich the allelic frequency for a few desired traits with strong additive QTL in early selection cycles while GS-MAS could be used in more mature breeding programs to additionally capture alleles with smaller additive effects.

Bibliographic Details

Main Authors:	Cerrudo, D., Shiliang Cao, Yibing Yuan, Martinez, C., Suarez, E.A., Babu, R., Xuecai Zhang, Trachsel, S.
Format:	Article biblioteca
Language:	English
Published:	Frontiers 2018
Subjects:	AGRICULTURAL SCIENCES AND BIOTECHNOLOGY, Genomic Selection, Marker Assisted Selection, QTL, DH, ARTIFICIAL SELECTION, GENETIC GAIN, DROUGHT, QUANTITATIVE TRAIT LOCI,
Online Access:	https://hdl.handle.net/10883/19502
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