Genetic variability and QTL mapping of freezing tolerance and related traits in [i]Medicago truncatula[/i]
2013
Avia, Komlan | Pilet-Nayel, Marie-Laure | Bahrman, Nasser | Baranger, Alain | Delbreil, Bruno | Fontaine, Véronique | Hamon, Céline | Hanocq, Eric | Niarquin, Martine | Sellier-Richard, Hélène | Vuylsteker, Christophe | Prosperi, Jean-Marie | Lejeune-Henaut, Isabelle | Stress Abiotiques et Différenciation des Végétaux Cultivés (SADV) ; Institut National de la Recherche Agronomique (INRA)-Université de Lille, Sciences et Technologies | Department of Biology, Plant Genetics Group ; University of Oulu [Finland] = Oulun yliopisto [Suomi] = Université d'Oulu [Finlande] | Institut de Génétique, Environnement et Protection des Plantes (IGEPP) ; Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST | Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
International audience
显示更多 [+] 显示较少 [-]英语. Freezing is a major environmental limitation to crop productivity for a number of species including legumes. We investigated the genetic determinism of freezing tolerance in the model legume Medicago truncatula Gaertn (M. truncatula). After having observed a large variation for freezing tolerance among 15 M. truncatula accessions, the progeny of a F6 recombinant inbred line population, derived from a cross between two accessions, was acclimated to low above-freezing temperatures and assessed for: (a) number of leaves (NOL), leaf area (LA), chlorophyll content index (CCI), shoot and root dry weights (SDW and RDW) at the end of the acclimation period and (b) visual freezing damage (FD) during the freezing treatment and 2 weeks after regrowth and foliar electrolyte leakage (EL) 2 weeks after regrowth. Consistent QTL positions with additive effects for FD were found on LG1, LG4 and LG6, the latter being the most explanatory (R (2) a parts per thousand 40 %). QTL for NOL, QTL for EL, NOL and RDW, and QTL for EL and CCI colocalized with FD QTL on LG1, LG4 and LG6, respectively. Favorable alleles for these additive effects were brought by the same parent suggesting that this accession contributes to superior freezing tolerance by affecting plants' capacity to maintain growth at low above-freezing temperatures. No epistatic effects were found between FD QTL, but for each of the studied traits, 3-6 epistatic effects were detected between loci not detected directly as QTL. These results open the way to the assessment of syntenic relationships between QTL for frost tolerance in M. truncatula and cultivated legume species.
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