Latencia en semillas de Stylosanthes hamata (Leguminosae) y su relación con la morfología de la cubierta seminal

Abstract:

The seed of Stylosanthes hamata is characterized by it's a high level of dormancy, which is imposed by seed-coat impermeability to water entry (harseededness or hard-seed condition). The level of hardseededness between upper and lower articulations of seven diploid and five tetraploid accessions was studied under tropical conditions. Germination tests on naked seeds (relative humidity: 55-65%, constant temperature: 27-30°C, photoperiod: 12/12 hr) showed that hard-seed percentage was, in most cases, over 85% independent of ploidy level and seed position within the fruit. Histochemical analysis indicated that hardseededness in this species was associated with a completely sealed microphile and hilum. This feature was also associated to: a) an epidermis consisting of a palisade-like layer of macrosclereids, b) a like-line at the outermost region of these cells and c) a high concentration of hydrophobic compounds located all across the seed-coat.

Año de publicación:

2001

Keywords:

• Hardseededness, dormancy
• Seed-coat
• germination
• Hard-seed
• Stylosanthes hamata
• Morpho-anatomical features

Fuente:

scopus