title: Impact of domestication on the phenotypic architecture of durum wheat under contrasting nitrogen fertilization.
abstract: The process of domestication has led to dramatic morphological and physiological changes in crop species due to adaptation to cultivation and to the needs of farmers. To investigate the phenotypic architecture of shoot- and root-related traits and quantify the impact of primary and secondary domestication, we examined a collection of 36 wheat genotypes under optimal and nitrogen-starvation conditions. These represented three taxa that correspond to key steps in the recent evolution of tetraploid wheat (i.e. wild emmer, emmer, and durum wheat). Overall, nitrogen starvation reduced the shoot growth of all genotypes, while it induced the opposite effect on root traits, quantified using the automated phenotyping platform GROWSCREEN-Rhizo. We observed an overall increase in all of the shoot and root growth traits from wild emmer to durum wheat, while emmer was generally very similar to wild emmer but intermediate between these two subspecies. While the differences in phenotypic diversity due to the effects of primary domestication were not significant, the secondary domestication transition from emmer to durum wheat was marked by a large and significant decrease in the coefficient of additive genetic variation. In particular, this reduction was very strong under the optimal condition and less intense under nitrogen starvation. Moreover, although under the optimal condition both root and shoot traits showed significantly reduced diversity due to secondary domestication, under nitrogen starvation the reduced diversity was significant only for shoot traits. Overall, a considerable amount of phenotypic variation was observed in wild emmer and emmer, which could be exploited for the development of pre-breeding strategies.
authors.affiliation: Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria Centro di Ricerca per la Cerealicoltura (CRA-CER), S.S. 673 km 25,200, 71122, Foggia, Italy Institute of Biosciences and Geosciences (IBG-2): Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: Tania
authors.initials: T
authors.lastname: Gioia
authors.affiliation: Institute of Biosciences and Geosciences (IBG-2): Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: Kerstin A
authors.initials: KA
authors.lastname: Nagel
authors.affiliation: Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria Centro di Ricerca per la Cerealicoltura (CRA-CER), S.S. 673 km 25,200, 71122, Foggia, Italy.
authors.forename: Romina
authors.initials: R
authors.lastname: Beleggia
authors.affiliation: Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria Centro di Ricerca per la Cerealicoltura (CRA-CER), S.S. 673 km 25,200, 71122, Foggia, Italy.
authors.forename: Mariagiovanna
authors.initials: M
authors.lastname: Fragasso
authors.affiliation: Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria Centro di Ricerca per la Cerealicoltura (CRA-CER), S.S. 673 km 25,200, 71122, Foggia, Italy.
authors.forename: Donatella Bianca Maria
authors.initials: DB
authors.lastname: Ficco
authors.affiliation: Institute of Biosciences and Geosciences (IBG-2): Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Pieruschka
authors.affiliation: Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria Centro di Ricerca per la Cerealicoltura (CRA-CER), S.S. 673 km 25,200, 71122, Foggia, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: De Vita
authors.affiliation: Institute of Biosciences and Geosciences (IBG-2): Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: Fabio
authors.initials: F
authors.lastname: Fiorani
authors.affiliation: Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria Centro di Ricerca per la Cerealicoltura (CRA-CER), S.S. 673 km 25,200, 71122, Foggia, Italy Institute of Biosciences and Geosciences (IBG-2): Plant Sciences, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università Politecnica delle Marche, via Brecce Bianche, 60131, Ancona, Italy roberto.papa@entecra.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Papa
mesh_terms: D005308:Fertilizers / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism; D010641:Phenotype; D000069600:Plant Breeding; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D057891:Tetraploidy; D014908:Triticum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D005308:Fertilizers; D009584:Nitrogen
keywords: Image analysis; Triticum spp.; nitrogen fertilization; phenotyping; pre-breeding; root; shoot