Efeitos morfo-anatômicos do extrato de Sphagneticola trilobata (L.) Pruski em sementes e plântulas de corda-de-viola

Abstract

Studies have shown that extracts from different species of the Asteraceae family are capable of inhibiting weed germination. Thus, the objective of this work is to analyse possible morpho-anatomical modifications in seeds of Ipomoea trilobaL. (morning glory) treated with extract of the species Sphagneticola trilobata(L.) Pruski (wedelia), in order to evaluate the use fulness of the wedeliain the infestation control by the morning glory weed. For this, leaves and stems of the wedelia were collected in the city of Santa Helena –PR and dried in air-circulation ovens at 45°C. The seeds were submitted to dormancy breaking by thermal shock at 50°C and disinfestation in 10% sodium hypochlorite. For the in vitrogermination test, 20 seeds were placed in Petri dishes containing filter paper moistened with the control solution (distilled water) and with the test solutions (extract and glyphosate at concentrations of 1.0 mg/ml). Seed germination was carried out in BOD with 70% humidity, temperature at 35°C and 12h light-dark cycle. In the morphological studies carried out, it was found that the wedelia leaf rinsingextract at 1.0 mg/ml causes alterations in the fissure pattern and fragmentation of the coatof the morning gloryseeds, as well as alterations in the radicle development. Changes in these characteristics were also observed in seeds treated with glyphosate, suggesting that wedelia may contain substances of interest for the development of a new herbicide to control the viola string.