Biometry and pre-germinative treatments of seeds from an Amazon endemic species

Abstract

This study aimed to verify the impact of different methods of overcoming dormancy in the germination of Ipomoea cavalcantei seeds, in addition to surveying the biometric data of its seeds and fruits. Ripe fruits were randomly collected from the species’ habitat, which is a unique ecosystem characterized by small vegetation and iron outcrops. For the biometric analyses, the weight, moisture content, length, width, and thickness of 100 fruits and 100 seeds were determined. To analyse the efficiency of overcoming seed dormancy, six different treatments were tested, including mechanical, physical, and chemical methods, and the resultant germinability, average germination time, and germination speed index were evaluated. Further, in order to estimate the imbibition curve, two treatments were selected to measure the water absorption rate of the seeds until the root emission of at least 50 % of the seeds. The results showed that the I. cavalcantei fruits and seeds biometrically vary in length, width, and thickness, which makes it difficult to obtain standard in situ samples. Moreover, mechanical scarification methods were the most efficient treatments to increase the efficiency of obtaining seedlings of this species. This study can contribute to ex situ conservation strategies for this endemic species, which is threatened by increasing mining activities.