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The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification
Lucerne (Medicago sativa), a major perennial pasture legume, belongs to a species complex that includes several subspecies with wild and cultivated populations. Stand establishment may be compromised by poor germination. Seed scarification, deterioration and temperature have an impact on germination...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7860617/ https://www.ncbi.nlm.nih.gov/pubmed/33552093 http://dx.doi.org/10.3389/fpls.2020.578121 |
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author | Ghaleb, Wagdi Ahmed, Lina Qadir Escobar-Gutiérrez, Abraham J. Julier, Bernadette |
author_facet | Ghaleb, Wagdi Ahmed, Lina Qadir Escobar-Gutiérrez, Abraham J. Julier, Bernadette |
author_sort | Ghaleb, Wagdi |
collection | PubMed |
description | Lucerne (Medicago sativa), a major perennial pasture legume, belongs to a species complex that includes several subspecies with wild and cultivated populations. Stand establishment may be compromised by poor germination. Seed scarification, deterioration and temperature have an impact on germination. The objective of this study was to analyse the genetic diversity of lucerne germination in response to three factors: (1) temperature, with seven constant temperatures ranging from 5 to 40°C, was tested on 38 accessions, (2) seed scarification was tested on the same accessions at 5 and 22°C, (3) seed deterioration was tested on two accessions and two seed lots at the seven temperatures. The germination dynamics of seed lots over time was modelled and three parameters were analysed: germinability (germination capacity), maximum germination rate (maximum% of seeds germinating per time unit), and lag time before the first seed germinates. Seed scarification enhanced germinability at both temperatures and its effect was much higher on falcata and wild sativa accessions. Incomplete loss of the hardseededness trait during domestication and selection is hypothesised, indicating that the introduction of wild material in breeding programmes should be followed by the selection for germinability without scarification. Seed lots with altered germinability had low germination at extreme temperatures, both cold and hot, suggesting that mild temperatures are required to promote germination of damaged seed lots. A large genetic diversity was revealed for germination (both capacity and rate) in response to temperature. All accessions had an optimal germination at 15 or 22°C and a poor germination at 40°C. The sativa varieties and landraces had a high germination from 5 to 34°C while the germination of falcata and the wild sativa accessions were weakened at 5 or 34°C, respectively. These differences are interpreted in terms of adaptation to the climate of their geographical origin regions in order to escape frost or heat/drought risks. These new findings give insights on adaptation and domestication of lucerne in its wide geographic area. They suggest further improvement of germination is needed, especially when introducing wild material in breeding pools to remove scarification requirements and to limit differences in response to temperature. |
format | Online Article Text |
id | pubmed-7860617 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-78606172021-02-05 The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification Ghaleb, Wagdi Ahmed, Lina Qadir Escobar-Gutiérrez, Abraham J. Julier, Bernadette Front Plant Sci Plant Science Lucerne (Medicago sativa), a major perennial pasture legume, belongs to a species complex that includes several subspecies with wild and cultivated populations. Stand establishment may be compromised by poor germination. Seed scarification, deterioration and temperature have an impact on germination. The objective of this study was to analyse the genetic diversity of lucerne germination in response to three factors: (1) temperature, with seven constant temperatures ranging from 5 to 40°C, was tested on 38 accessions, (2) seed scarification was tested on the same accessions at 5 and 22°C, (3) seed deterioration was tested on two accessions and two seed lots at the seven temperatures. The germination dynamics of seed lots over time was modelled and three parameters were analysed: germinability (germination capacity), maximum germination rate (maximum% of seeds germinating per time unit), and lag time before the first seed germinates. Seed scarification enhanced germinability at both temperatures and its effect was much higher on falcata and wild sativa accessions. Incomplete loss of the hardseededness trait during domestication and selection is hypothesised, indicating that the introduction of wild material in breeding programmes should be followed by the selection for germinability without scarification. Seed lots with altered germinability had low germination at extreme temperatures, both cold and hot, suggesting that mild temperatures are required to promote germination of damaged seed lots. A large genetic diversity was revealed for germination (both capacity and rate) in response to temperature. All accessions had an optimal germination at 15 or 22°C and a poor germination at 40°C. The sativa varieties and landraces had a high germination from 5 to 34°C while the germination of falcata and the wild sativa accessions were weakened at 5 or 34°C, respectively. These differences are interpreted in terms of adaptation to the climate of their geographical origin regions in order to escape frost or heat/drought risks. These new findings give insights on adaptation and domestication of lucerne in its wide geographic area. They suggest further improvement of germination is needed, especially when introducing wild material in breeding pools to remove scarification requirements and to limit differences in response to temperature. Frontiers Media S.A. 2021-01-21 /pmc/articles/PMC7860617/ /pubmed/33552093 http://dx.doi.org/10.3389/fpls.2020.578121 Text en Copyright © 2021 Ghaleb, Ahmed, Escobar-Gutiérrez and Julier. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Plant Science Ghaleb, Wagdi Ahmed, Lina Qadir Escobar-Gutiérrez, Abraham J. Julier, Bernadette The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification |
title | The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification |
title_full | The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification |
title_fullStr | The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification |
title_full_unstemmed | The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification |
title_short | The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification |
title_sort | history of domestication and selection of lucerne: a new perspective from the genetic diversity for seed germination in response to temperature and scarification |
topic | Plant Science |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7860617/ https://www.ncbi.nlm.nih.gov/pubmed/33552093 http://dx.doi.org/10.3389/fpls.2020.578121 |
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