Seed mass affects emergence but not germination in native grassland forage species

MILANO, CLARA; PÉREZ, DANIEL ROBERTO; SCARFÓ, MARIA CECILIA; RODRIGUEZ, DANA AYLEN; CUPPARI, SELVA Y.; LOYDI, ALEJANDRO

RESTORATION ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2024

1061-2971

For ecological restoration of degraded grasslands, species selection and knowledge of the species biology are essential. Seed germination andseedlingestablishment,aswell asseedregenerative traits, canpartially determine directseeding success in this context. The objectives of this study are(1)tocharacterize the seedsof29native forage species ofthePampaAustralgrasslands, (2) to evaluate their germination and emergence, and (3) to evaluate the relationship between germination and emergence and seed traits (mass, length, width, and length/width ratio), to test the usefulness of these traits for rapid species selection. We studied the germination percentage of untreated (UG) and treated (TG) seeds under laboratory conditions of 29 native forage species (four legumes, nine cool season, and 16 warm-season grasses) and the percentage of field emergence (FE) for 17 of those species, selected based on their UG. Additionally, all species were characterized, including thousand-seed mass, length, width, and length/width ratio. Average UG was 53.30 3.17% for Poaceae and 25.63 5.73% for Fabaceae. Four cool season and eight warm-season grasses had UG greater than 60%. Mean FE was 35.18 0.66% 2 months after sowing. FE has a direct relationship with seed mass (r2 = 0.69; p < 0.001), while this relationship was not observed for UG under laboratory conditions (r2 = 0.15; p = 0.7174). In Pampa Austral grasslands, seed mass proved to be a relevant trait for species selection given its strong relationship with FE.