A 3D analysis of the reproductive development of Eragrostis curvula (Schrad.) Ness

PASTEN, C; CARBALLO, J; DIAZ AR; MIZZOTI C; CUCINOTTA, M; COLOMBO, L; ECHENIQUE, V; MENDES, MA

Congreso; IV International Congress on Apomixis; 2024

Apomixis, defined as asexual propagation by seeds, is a type of plant reproduction found in more than 400 angiosperms. This polyphyletic trait has been studied in various species, and it is considered of great importance in the agricultural industry as it would allow the fixation of desired traits and its propagation through generations. The study of ovule development in an apomictic model is necessary to strengthen the knowledge of the mechanisms governing this reproductive mode, and would contribute to improve plant breeding procedures.Weeping lovegrass (Eragrostis curvula (Schrad.) Ness) is a perennial grass that has been extensively studied as a model species for diplosporous apomixis. This species, mostly used as forage in semi-arid regions of the world, comprises a polymorphic complex that includes sexual and apomictic cytotypes, where all apomicts are polyploids, ranging from tetraploids (4X) to octoploids (8X).The aim of this work was to provide a thorough description of the developmental stages taking place in the ovule of three tetraploid genotypes of weeping lovegrass: the full apomictic Tanganyika, the facultative apomictic Don Walter, and the sexual OTA, as well as evaluating pollen development, using confocal laser microscopy. Moreover, in order to further understand the mode of reproduction in this species, an in situ hybridization (ISH) was performed using an SPL gene (Squamosa Promoter-binding-Like), found to be differentially expressed between two of the contrasting genotypes (OTA-S and Tanganyika).The present analysis of the female gametophyte aided in increasing the knowledge of the reproductive development in E. curvula and allowed the identification of differences between sexual and apomictic development