Heteromorphic seeds of wheat wild relatives show germination niche differentiation. (10th December 2019)

• Record Type: Journal Article
• Authors: Gianella, M.; Balestrazzi, A.; Pagano, A.; Müller, J. V.; Kyratzis, A. C.; Kikodze, D.; Canella, M.; Mondoni, A.; Rossi, G.; Guzzon, F.
• Editors: Byers, D.
• Is Part Of: Plant biology. Volume 22:Number 2(2020)
• Page Start: 191
• Page End: 202
• Publication Date: 2019-12-10
• Subjects: Aegilops -- antioxidants -- controlled ageing test -- functional traits -- seed dimorphism -- seed germination -- seed longevity; Botany -- Periodicals; Plants -- genetics -- Periodicals; Plants -- growth & development -- Periodicals; Plant Proteins -- Periodicals; Gene Expression Regulation, Plant -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1111/plb.13060
• Languages: English
• ISSNs: 1435-8603

Abstract

Abstract: Crop wild relatives are fundamental genetic resources for crop improvement. Wheat wild relatives often produce heteromorphic seeds that differ in morphological and physiological traits. Several Aegilops and Triticum species possess, within the same spikelet, a dimorphic seed pair, with one seed being larger than the other. A comprehensive analysis is needed to understand which traits are involved in seed dimorphism and if these aspects of variation in dimorphic pairs are functionally related. To this end, dispersal units of Triticum urartu and five Aegilops species were X‐rayed and the different seed morphs weighed. Germination tests were carried out on seeds, both dehulled and left in their dispersal units. Controlled ageing tests were performed to detect differences in seed longevity among seed morphs, and the antioxidant profile was assessed in terms of antioxidant compounds equipment and expression of selected antioxidant genes. We used PCA to group seed morphs sharing similar patterns of germination traits, longevity estimates and antioxidant profile. Different seed morphs differed significantly in terms of mass, final germination, germination timing, longevity estimates and antioxidant profile in most of the tested species. Small seeds germinated slower, had lower germination when left in their dispersal units, a higher antioxidant potential and were longer‐lived than large seeds. The antioxidant gene expression varied between morphs, with different patterns across species but not clearly reflecting the phenotypic observations. The results highlight different trait trade‐offs in dimorphic seeds of Aegilops and T. urartu, affecting their germination phenology and longevity, thereby resulting in recruitment niche differentiation. Abstract : Seed heteromorphy in wheat wild relatives is analyzed using both eco‐physiological and molecular approaches, revealing that morphs cluster, regardless the species, by different intertwined seed functional traits".