A discipline called allelopathy

Rizvi, S. J. H.; Haque, H.; Singh, Vijay K.; Rizvi, V.

doi:10.1007/978-94-011-2376-1_1

Cited by 93 publications

(78 citation statements)

References 8 publications

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“…De forma similar, os extratos aquosos de folhas e cascas de tronco de canela-sassafrás inibiram a produção de clorofila de plântulas de sorgo (Carmo et al, 2007). Segundo Rizvi et al (1992), certas classes de aleloquímicos, tais como os ácidos fenólicos, as cumarinas, os polifenóis e os flavonóides, interferem na fotossíntese por induzirem mudanças no conteúdo de clorofila das plantas e por alterarem o transporte de elétrons e a fosforilação nos fotossistemas.…”

Section: Resultsunclassified

“…Alterações em nível celular, fitormonal, fotossintético e respiratório, síntese proteica, metabolismo lipídico e de ácidos orgânicos, inibição ou estimulação da atividade enzimática específica, efeitos sobre a relação da água e efeitos sobre a síntese de DNA ou RNA compreendem efeitos diretos ocasionados pelos aleloquímicos. Efeitos indiretos compreendem interferência na produtividade da planta, de agroecossistemas e na biodiversidade local, por causar alterações na sucessão vegetal, na estrutura e composição das comunidades vegetais e na dominância de certas espécies vegetais (Rice, 1984;Rizvi et al, 1992).…”

Section: Introductionunclassified

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Potencial alelopático de extratos aquosos de frutos de Solanum americanum Mill. sobre as sementes de rabanete

Borella

Wandscheer

Pastorini

2011

Agraria

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Potencial alelopático de extratos aquosos de frutos de Solanum americanum Mill. sobre as sementes de rabanete RESUMO O objetivo deste trabalho foi investigar o potencial alelopático de extratos aquosos de frutos de erva-moura (Solanum americanum Mill.) sobre a germinação da semente e o crescimento inicial da plântula de rabanete (Raphanus sativus L.). Os extratos foram preparados nas concentrações 2; 4 e 8% e caracterizados quanto ao pH, potencial osmótico e perfil fitoquímico. Os testes foram constituídos de quatro repetições de 25 sementes de rabanete em placas de Petri contendo duas folhas de papel germitest e 5 mL de extrato aquoso. Para a germinação foram avaliados: a porcentagem de germinação (PG), a velocidade de germinação (VG), o índice de velocidade de germinação (IVG) e o coeficiente de uniformidade de germinação (CUG). Para o crescimento inicial foi avaliado: comprimento (radicular e da parte aérea), massa (fresca, seca e conteúdo de água) e teor de clorofila (a, b e total). Os extratos de frutos alteraram os parâmetros PG, VG e IVG para a germinação. Os extratos também causaram reduções no comprimento radicular, na massa fresca e nos teores de clorofila a. A ação dos extratos não está associada ao potencial osmótico e ao pH e os testes qualitativos de identificação revelam a presença de flavonóides, indicando, portanto, atividade alelopática. Palavras-chave:Alelopatia, germinação, crescimento inicial. Allelopathic potential of aqueous extracts of Solanum americanum Mill. fruits on radish seeds ABSTRACTThis study had the objective to test the allelopathic potential of aqueous extracts of nightshade fruits (Solanum americanum Mill.) on radish seed germination and leaflet early growth (Raphanus sativus L.). The extracts were prepared in the concentrations of 2, 4 and 8%, and characterized as to phytochemical profile, pH and osmotic potential. Treatments consisted of four replications of 25 radish seeds distributed in Petri dishes with two sheets of germitest paper and 5 mL of water extract. Germination parameters consisted of the germination percentage (PG), germination speed (VG), germination speed index (IVG) and germination uniformity coefficient (CUG). The initial growth was evaluated by length (root and shoot), mass (fresh, dried and water content) and chlorophyll content (a, b and total). The fruit extracts affected the PG, VG and IVG for germination. The extracts also reduced the root length, fresh mass and chlorophyll a levels. The extracts action is not related to the osmotic potential and pH and the qualitative identification tests reveals the presence of flavonoids, indicating allelopathic activity.

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Section: Resultsunclassified

Section: Introductionunclassified

Potencial alelopático de extratos aquosos de frutos de Solanum americanum Mill. sobre as sementes de rabanete

Borella

Wandscheer

Pastorini

2011

Agraria

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“…Allelochemicals aff ect various metabolic processes in or-ganisms: altering membrane permeability and ion absorption ; inhibiting electron transport in photosynthesis and respiration (Abrahim et al 2000); changing enzyme activity (Singh et al 2009); and impeding cell division (Teerarak et al 2010). Because of these eff ects, allelopathy is recognized as an important ecophysiological process in ecosystems, infl uencing primary and secondary plant succession, as well as the structure, composition and dynamics of native or cultivated plant communities (Rizvi et al 1992;Scrivanti et al 2003). In addition, allelopathy plays a key role in the detection of bioactive compounds of commercial importance (Oliveros-Bastidas 2008).…”

Section: Introductionmentioning

confidence: 99%

Interspecific variation in the allelopathic potential of the family Myrtaceae

2013

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Allelopathy is a type of biotic interference wherein a plant releases bioactive metabolites into an environment, thereby aff ecting the adjacent biota. Stressful environments stimulate the production of these metabolites. Th e present study tests the novel weapons hypothesis, which postulates that species belonging to the same genus and from the same environment have similar allelopathic eff ects. Th e aim of this study was to assess the allelopathic eff ects that the aqueous leaf extracts of 15 species belonging to fi ve genera of the Myrtaceae family have on the seed germination and initial seedling growth of lettuce (Lactuca sativa L.), tomato (Solanum lycopersicum L.) and onion (Allium cepa L.). Germination rates, average germination times, informational entropy of germination and allelopathic eff ects, as quantifi ed with a response index, were calculated. A taxonomic distance matrix based on Gower dissimilarity and a Euclidean distance matrix were constructed. Th e results revealed that all extracts from donor species signifi cantly increased average germination time or reduced the germination rate of eudicotyledonous plant species. Th e only extracts that showed no eff ect on monocotyledonous seeds were those of Campomanesia pubescens O. Berg and Psidium cinereum Mart. We conclude that eudicotyledonous and monocotyledonous plants were both signifi cantly aff ected by the presence of all extracts tested. Our results make it clear that each species behaves distinctly in relation to allelopathic activity, with no apparent grouping by genus or subtribe. Th erefore, the hypothesis was rejected, because plants from the same environment and with taxonomic proximity do not necessarily display similar production of secondary metabolites.

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“…Allelochemicals produced by one crop species can influence the growth, productivity, and yield of other crops or the same crop . The avoidance of allelopathic effects between crops, or the exploitation of beneficial interactions in a rotation or a mixed cropping system may have direct bearing on the crop yield (Rizvi et al, 1992). In the present study, the allelopathic effects of ginger rhizome, stem and leaf aqueous extracts were examined to determine if inhibitory or stimulatory effects of ginger extracts influence seed germination and seedling growth of two crops (soybean and chive) that are commonly intercropped with ginger.…”

Section: Introductionmentioning

confidence: 99%