Morphological and physiological germination aspects of Anadenanthera colubrina (Vell.) Brenan

Abstract

Anadenanthera colubrina is a species native to Brazil, from the Fabaceae family and has potential for use in the timber industry, in the reforestation of degraded areas, besides having medicinal properties. Its propagation is mainly by seeds, but basic subsidies regarding the requirements for optimal germination conditions are still lacking. Aiming to contribute to the expansion of its cultivation, rational use and conservation, the objective of this study was to investigate the morphology and anatomy of fruits and seeds, as well as the responses to factors as thermal regimes and substrates in seed germination. The 1000-seed weight and seeds per fruit were determined. To characterize the seed tissues, histochemical test with Sudan III and Lugol was used. The temperatures analyzed in the germination test were 15-25 C; 25 C; 20-30 C and 30 C. Different substrates for germination (paper rolls, paper sheet such as germitest, commercial substrate and sand) were also analyzed in the presence of light at 30 C. The average number of seeds per fruit is 10 and the 1000-seed weight is 118 g. Germination is fast and high over a wide temperature range; however, the temperature of 25 C contributes to a substantial increase in the percentage of abnormal seedlings and dead seeds, both in the absence and presence of light. A. colubrina seeds are indifferent to light and the highest vigor was verified at 30 C. Sand and commercial substrates are efficient in initial seedling development.