Effect of aqueous smoke extract on the germination of Solanum lycocarpum St. Hil. and Solanum granulosoleprosum Dunal (Solanaceae) seeds

Abstract

Aqueous smoke extract (ASE) is a low-cost alternative which shows high effectiveness in optimizing seed germination. The objective of this study was to evaluate the effect of different aqueous smoke extract doses on the germination of Solanum lycocarpum St. Hil. and Solanum granulosoleprosum Dunal seeds. Two seed lots of S. granulosoleprosum were used, collected in 2016 and in June 2019, both in the region of Lavras, Minas Gerais. S. lycocarpum seeds were also collected in the Lavras region, in June 2019. The concentrations used for germination were distilled water (control) and ASE diluted in water at the following ratios: 1:5, 1:10, 1:20, 1:40, and 1:80 (v/v). The plates containing the seeds were incubated in a BOD chamber under alternating temperatures of 20 and 30 °C and a 12-hour photoperiod. The experiments were conducted in a completely randomized design, with the data subjected to analysis of variance and the means compared using Tukey’s test (p < 0.05). The experiment with S. granulosoleprosum was conducted in a two-factor factorial design (2 storage times × 6 concentrations). S. lycocarpum did not respond to the ASE treatments. S. granulosoleprosum seeds collected in 2016 and stored showed higher germination and germination speed index (GSI) compared to seeds collected in 2019 (not stored). The 1:5 and 1:20 dilutions significantly increased germination and GSI of S. granulosoleprosum seeds (2019 lot). It is concluded that all treatments improved germination and GSI compared to the control for S. granulosoleprosum seeds collected in 2019, whereas the treatments were not effective for S. lycocarpum seeds.

Keywords: Smoked water, Seed vigor, Seed technology