Publicação on-line; 28 ref.; 3 tables; 7 illus.; Summary (En)

ABSTRACT

Seed coat plays an important role in the embryo protection and seed germination. This study
aimed to characterize the anatomical structure, histochemical and physicochemical aspects of
the seed coat of Araucaria angustifolia Kuntze. Light and scanning microscopy usual procedures,
and histochemical tests were used to describe and characterize seed layers, as well as to determine
their extractive contents. Functional groups of the integument coat layers were observed by
Fourier transformed infrared spectroscopy. Color analyses were performed in CIE 1976 L*a*b*
color space. Wettability of the layers was evaluated by contact angle analysis. The anatomical
and chemical features observed in the seed layers include the rucose cuticle and the presence of
many layers of sclerenchyma in the mesotesta; and the chromaticity due to extractive content
and phenolic compounds in the endotesta. The wettability varied among layers according to
their structure. These features information contribute to a better understanding on the services
provided by the Araucaria angustifolia seed coat.

Keywords: pinhão, colorimetry, conifers, contact angle analysis, FT-IR spectroscopy.