Phyton (Buenos Aires)
versão On-line ISSN 1851-5657
LOVEY, RJ; PERISSE, P; VIEYRA, C e CORAGLIO, JC. Seed, germination and seedling characterization of Cologania broussonetii (Balb.) DC. Phyton (B. Aires) [online]. 2010, vol.79, n.1, pp. 5-10. ISSN 1851-5657.
Cologania broussonetii (Balb.) DC. (Fabaceae) grows from the Bolivian eastern Andes to the north west of Argentina, Cordoba hills and San Luis Province. It is recognized as a native forage. The objectives of this study were to characterize the seed, the germination and the seedling of C. broussonetii. Seed structure was characterized through free hand sections and analyzed with optical and stereoscopic microscopy. The germination assay treatments were: (1) intact non-scarfied seeds at 25 °C constant, (2) scarified seeds at 25 °C constant, (3) intact non-scarified seeds at 20-30 °C alternating, and (4) scarified seeds at 20-30 °C alternating. Results showed that seed is variable in shape depending upon its position within the legume. Seed coat is shiny, reddish brown with black streaks. The hilum is surrounded by a corona and it presents an aril with double hilar tongue. The micropyle is deltoid and the lens is visible. The embryo accumulates reserve substances and it is surrounded by a conspicuous endosperm layer. The embryo is in axile position investing subtype, the plumule is moderately developed and the radicle apex, protected by a radicle pocket, is triangular. Germination assays showed that scarified seeds exceeded 90% germination; meanwhile intact seeds did not reach the 50%. Maximum germination occurred at 20-30 °C, 15 days after seeding. Germination is phaneroepigeal; cotyledons present entire margin, the first pair of leaves is unifoliolated subtended by a pair of stipules. The following alternating leaves are trifoliolated and stipulated. Seedling morphology of C. broussonetii corresponds with the types Sloanea subtypes Sloanea and Sophora.
Palavras-chave : Cologania broussonetii; Seed; Scarification; Germination; Seedling.