Viabilidade de sementes de Ipomoea cavalcantei(Convolvulaceae) submetidas a diferentes períodos de armazenamento.

Abstract

Ipomoea cavalcantei is an endemic species of the Carajás National Forest-PA Brazil and is at risk of extinction due to the loss of its habitat by mineral exploration. The objective of this work was to evaluate the viability of I. cavalcantei seeds submitted to different storage periods. The fruits were manually collected from randomly selected plants in the Canga areas of N1 and N2. The work was carried out at the Laboratory of Plant Physiology of the Federal Rural University of Amazonia (UFRA), Campus Parauapebas-PA. The experiment was carried out in a completely randomized design, in split-plots in time, under storage conditions in a refrigerated environment at 05°C for periods of 0, 45 and 90 days. The variables evaluated were moisture content (TU), electrical conductivity (EC) and a germination test (TG) was performed. With the TG, the Germination Percentage (G%), the germination speed index (IVG) and the mean germination time (TMG) were determined. All results were submitted to the Shapiro-Wilk test, data from TG, TU and EC were analyzed using analysis of variance – ANOVA. Data from TU and G%, IVG and TMG were submitted to the Holm-Sidak test at 5% probability. EC data were submitted to Linear Regression analysis and Tukey's test at 5% probability. Statistical and graphic analyzes were carried out using the SIGMA PLOT software, version 12. Seeds kept in storage for up to 90 days, regardless of the seed collection areas, under the evaluated conditions maintain good moisture content T0, T45 and T90: 14.24±0.74%, 11.22±0.76% and 12.0±0.47% respectively, preserve germinability, with percentages that do not differ within the same area (N1 and N2) between areas. Electrical conductivity showed that Ipomoea cavalcantei seeds maintained their vigor during different storage times.