Phytochemical analysis and allelopathic effects of Pouteria ramiflora bark on lettuce seeds germination

Allelopathy is the ability that a plant has to interfere in the metabolism of another plant by means of substances released into the environment, being a potential alternative to control weeds, avoiding the use of herbicides. The purpose of this study was to evaluate the allelopathic potential of the bark ofP. ramiflora in germination and initial growth of lettuce seeds. The extracts were obtained by turbolise, 40 g of the plant to 200 mL of water/ethanol; bioassays were diluted in the crude extract (20%) at concentrations of 2.5, 5, 10 and 15% and the statistical design was completely randomized and the averages compared by Tukey test. There was no change in germination in any of the evaluated concentrations of the extract (aqueous and ethanolic part, external and internal) from the bark of P. ramiflora. Germination speed index and average time of germination were not affected by any treatment. However, the different concentrations affected root and shoot development, mainly 2.5 and 5.0% of the ethanolic extract inside of the bark (internal part), effect related to the presence of steroids and triterpenes found only in this extract. The bark of P. ramiflora did not hamper germination rates, but presented allelochemicals that interfere negatively on the growth of lettuce seedlings, indicating allelopathic effect and potential use.

Lactuca sativa; allelopathy; allelochemicals; Sapotaceae; curriola

Associação Brasileira de Horticultura UFRPE (Universidade Federal Rural de Pernambuco, Rua Manoel de Medeiros s/n, Dois Irmãos,, 52171-900 Recife-PE, Tel. (81) 3320 6064, - Vitoria da Conquista - BA - Brazil