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Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field

BACKGROUND AND AIMS: In oilseed rape (Brassica napus) semi-dwarf hybrid varieties from crosses between bzh dwarf and normal-type lines are of increasing interest. They have improved nitrogen (N) uptake, N-utilization and N-use efficiency compared to normal types. This study aimed to elucidate whethe...

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Autores principales: Schierholt, Antje, Tietz, Tina, Bienert, Gerd Patrick, Gertz, Andreas, Miersch, Sebastian, Becker, Heiko C
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6881224/
https://www.ncbi.nlm.nih.gov/pubmed/30452536
http://dx.doi.org/10.1093/aob/mcy197
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author Schierholt, Antje
Tietz, Tina
Bienert, Gerd Patrick
Gertz, Andreas
Miersch, Sebastian
Becker, Heiko C
author_facet Schierholt, Antje
Tietz, Tina
Bienert, Gerd Patrick
Gertz, Andreas
Miersch, Sebastian
Becker, Heiko C
author_sort Schierholt, Antje
collection PubMed
description BACKGROUND AND AIMS: In oilseed rape (Brassica napus) semi-dwarf hybrid varieties from crosses between bzh dwarf and normal-type lines are of increasing interest. They have improved nitrogen (N) uptake, N-utilization and N-use efficiency compared to normal types. This study aimed to elucidate whether these N-related effects can be explained by the bzh shoot growth-type alone or also by differences in root traits. METHODS: Root system size was measured using root electrical capacitance (EC) in field trials with two N levels in two sets of genotypes segregating for the bzh-locus: (1) 108 doubled haploid (DH) test hybrids in two seasons, 2010–2012, and (2) 16 near-isogenic hybrids in the 2016–17 season. Quantitative trait loci (QTL) for root EC were estimated in DH test hybrids. Seedling root architecture parameters were monitored in vitro. KEY RESULTS: In vitro root growth showed a higher root: shoot ratio in bzh semi-dwarf hybrids. Root EC in field trials was higher at high N supply than at zero N fertilization. In most trials semi-dwarf hybrids had higher EC than normal-type hybrids, but they reduced root EC in response to N limitation more than normal types. Root EC was more heritable at the end of flowering (h(2) = 0.73) than at the beginning of flowering (h(2) = 0.36) in near-isogenic hybrids and had a lower heritability in trials of DH test hybrids (h(2) = 0.27). A QTL for root EC in the genomic region of the bzh-locus on linkage group A06 was significant at zero N fertilization. CONCLUSIONS: Root EC proved to be a meaningful method in oilseed rape breeding programmes targeting root system size. The greater reduction of semi-dwarf root EC compared to the normal type under low N supply with simultaneous increase in N efficiency implies that in roots it is not a question of ‘the more the merrier’ and that the bzh root system reacts highly economically when N is scarce.
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spelling pubmed-68812242019-12-03 Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field Schierholt, Antje Tietz, Tina Bienert, Gerd Patrick Gertz, Andreas Miersch, Sebastian Becker, Heiko C Ann Bot Original Articles BACKGROUND AND AIMS: In oilseed rape (Brassica napus) semi-dwarf hybrid varieties from crosses between bzh dwarf and normal-type lines are of increasing interest. They have improved nitrogen (N) uptake, N-utilization and N-use efficiency compared to normal types. This study aimed to elucidate whether these N-related effects can be explained by the bzh shoot growth-type alone or also by differences in root traits. METHODS: Root system size was measured using root electrical capacitance (EC) in field trials with two N levels in two sets of genotypes segregating for the bzh-locus: (1) 108 doubled haploid (DH) test hybrids in two seasons, 2010–2012, and (2) 16 near-isogenic hybrids in the 2016–17 season. Quantitative trait loci (QTL) for root EC were estimated in DH test hybrids. Seedling root architecture parameters were monitored in vitro. KEY RESULTS: In vitro root growth showed a higher root: shoot ratio in bzh semi-dwarf hybrids. Root EC in field trials was higher at high N supply than at zero N fertilization. In most trials semi-dwarf hybrids had higher EC than normal-type hybrids, but they reduced root EC in response to N limitation more than normal types. Root EC was more heritable at the end of flowering (h(2) = 0.73) than at the beginning of flowering (h(2) = 0.36) in near-isogenic hybrids and had a lower heritability in trials of DH test hybrids (h(2) = 0.27). A QTL for root EC in the genomic region of the bzh-locus on linkage group A06 was significant at zero N fertilization. CONCLUSIONS: Root EC proved to be a meaningful method in oilseed rape breeding programmes targeting root system size. The greater reduction of semi-dwarf root EC compared to the normal type under low N supply with simultaneous increase in N efficiency implies that in roots it is not a question of ‘the more the merrier’ and that the bzh root system reacts highly economically when N is scarce. Oxford University Press 2019-11 2018-11-17 /pmc/articles/PMC6881224/ /pubmed/30452536 http://dx.doi.org/10.1093/aob/mcy197 Text en © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Articles
Schierholt, Antje
Tietz, Tina
Bienert, Gerd Patrick
Gertz, Andreas
Miersch, Sebastian
Becker, Heiko C
Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field
title Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field
title_full Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field
title_fullStr Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field
title_full_unstemmed Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field
title_short Root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field
title_sort root system size response of bzh semi-dwarf oilseed rape hybrids to different nitrogen levels in the field
topic Original Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6881224/
https://www.ncbi.nlm.nih.gov/pubmed/30452536
http://dx.doi.org/10.1093/aob/mcy197
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