Alelopatia de Joanesia princeps Vell. e Casearia sylvestris Sw. sobre espécies cultivadas

Abstract

RESUMO:Metabólitos secundários produzidos em algumas plantas podem provocar alterações no desenvolvimento de outras plantas ou até mesmo de outros organismos. O objetivo do trabalho foi avaliar o efeito alelopático de extratos aquosos de folhas de Joanesia princeps e Casearia sylvestris na germinação e no desenvolvimento inicial de plântulas de Brassica oleracea cv. capitata, Lactuca sativa cv. grand rapids e Lycopersicum esculentum. Foram testadas seis concentrações de cada extrato (10, 30, 50, 70, 90 e 100%) além do controle água destilada. Os extratos aquosos de J. princeps e C. sylvestris reduziram e, ou inibiram significativamente o percentual de geminação das sementes, o crescimento inicial da parte aérea e do sistema radicular de todas as espécies cultivadas e causaram severas anormalidades nas plântulas. Os resultados indicam a existência de potencial alelopático de J. princeps e C. sylvestris. Unitermos:Joanesia princeps, Euphorbiaceae, Casearia sylvestris, Salicaceae, alelopatia, germinação, crescimento.ABSTRACT: "Allelopathy of Joanesia princeps Vell. and Casearia sylvestris Sw. on the cultivated species". Secondary metabolites produced in some plant species can provoke development changes in other plants or even in other organisms. The objective of this work was to identify the possible allelopathic effects of the aqueous extracts of Joanesia princeps and Casearia sylvestris leaves in the germination and initial growth of Brassica oleracea cv. capitata, Lactuca sativa cv. grand rapids and Lycopersicum esculentum seedlings. Six concentrations of each extract (10, 30, 50, 70, 90 and 100%) were tested besides distilled water control. The aqueous extracts of J. princeps and C. sylvestris significantly reduced the seed germination percentage, initial growth of the aerial section and root system of all cultivated species in which they caused severe seedlings damage. The results indicate existence of allelopathic potential in J. princeps and C. sylvestris.

Phytotoxicity of Tagetes erecta L. and Tagetes patula L. on plant germination and growth

“…Significant reductions were also observed for tests of seedling development with growth inhibition of root and hypocotyl for the same treatments previously mentioned and with dose-dependency according to Tables 2 and 3, demonstrating relationship with the phytotoxic action already reported for some allelochemical in plant development tests (Poonpaiboonpipat et al, 2013). The results obtained in this study were similar to Capobiango et al (2009) and Silva et al (2012), where extracts of leaves of the different plants showed reductional allelopathic effect on the germination indices and growth of L. sativa.…”

<b>Allelopathic bioactivity of fresh and infused aqueous extracts of Brazilian cherry (<i>Eugenia uniflora</i> L.) on lettuce and maize

“…The results from this study indicate that the roots are more sensitive to Brazilian cherry extracts than the shoots. This effect appears to be common in allelopathic studies, supported by the results obtained by Capobianco, Vestena, and Bitencourt (2009) and Al-Sherif, Hegazy, Gomaa, and Hassan (2013) all of which demonstrated that the allelopathic effects vary according to the exposed part of the plant. Imatomi et al (2015) suggested that this differential effect may be due to higher extract exposure of the roots, however, this does not apply in the current study as the shoots and roots were exposed to the extracts at the same intensity.…”

Study of Plants With Allelopathic Potential in the Initial Development of Lettuce

“…The abnormal seedlings showed necrotic primary root ends, absence of epicotyl, negative geotropism, swollen seeds and only radicle (Coelho et al, 2011). As well as the one found by Capobiango, Vestena, and Bittencourt (2009), who mention that the aqueous extracts of kernel seeds (Joanesia princeps) reduced and/or inhibited the germination of lettuce, and the reduction was greater with the increase of the concentrations used (Table 8). Note.…”