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Germination of newly collected diaspores of Myracrodruon urundeuva Allemão (Anacardiaceae) occurring in the cerrado of Central Brazil

Myracrodruon urundeuva occurs in Northeast, Southeast, and West Center Brazilian regions, being considered as a vulnerable species to extinction. Diaspores collected in the Araguari River valley, MG, were used in three experiments, in a completely randomized design, with five replications of 50 diaspores each one. In the first and second experiments, germination boxes with vermiculite moistened with distilled water, GA3 and cytokinin at 1, 10, 100 µg mL-1, and 0.2% KNO3 were used as treatments. The first experiment was conducted under continuous fluorescent white lamps and the second in darkness. In the third experiment the diaspores were moistened with distilled water and stratified during one to six days at 45 ºC in darkness. Control treatment was constituted by diaspores moistened with water, without stratification. For the experiments conducted under light conditions, data were collected observing the embryo protrusion every 24 hours; in darkness conditions counting was processed after seven days from the beginning of the experiment. Under continuous light, diaspores treated with 1 µg.mL¹ GA3 were more homogeneous (CVt = 17.13%) and synchronized (Z = 0.64) in relation to the other treatments. The germinability ranged from 52.8% to 60% and occurred between two and three days. In darkness condition, germinability ranged from 50.4% to 58.8% and under stratification, from 49.6% to 61.2%. For the experiment testing stratification, the lowest mean time, the highest rate and germination uniformity were registered for diaspores stratified during six days. Although the germination process had been fast, low germinability indicates that new investigations are necessary to the sustainable exploration of this species.

germination measurements; growth regulators; stratification


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