Allelopathic effects of Rhynchosia capitata on germination and seedling growth of mungbean

Abstract

-Experiments were conducted to evaluate the allelopathic influence of Rhynchosia capitata on germination and seedling growth of mungbean (Vigna radiate) along with identification of the phytotoxic substances responsible for this activity. Water extracts of root, shoot, leaf, fruit and whole plant were prepared by soaking them in water in a ratio of 1:20 (w/v) for 24 h. All the extracts affected germination and seedling growth of mungbean, but higher inhibition was seen with R. capitata leaf water extracts. A linear decrease in the germination characteristics of mungbean was observed with the decrease in the concentration of leaf extract from 5% to 1%. The soil-incorporated residues (1-4% w/w) of R. capitata stimulated the growth of root and hypocotyl at low concentrations, while it inhibited their growth at higher concentrations. Rhynchosia capitata soil-incorporated residues (4% w/w) significantly reduced the seedling vigour index of mungbean in addition to their significant effect on total germination. A significant amount of water-soluble phenolic acids were found in R. capitata plant extracts. The content of total phenolic acids was higher in the leaf extract compared to that of the stem, fruit or root extracts. Two phenolic acids including vanillic acid and 4-(hydroxymethyl) benzoic acid were found in R. capitata leaf extracts.Keywords: phytotoxic, phenolic, allelopathy, residues, concentration, water extracts. RESUMO -Experimentos foram conduzidos para avaliar a influência alelopática deRhynchosia capitata na germinação e crescimento das mudas de mungbean (Vigna radiate) juntamente com a identificacão das substâncias fitotóxicas responsáveis por esta atividade. Extratos aquosos da raiz, caule, folha, fruto e planta inteira foram preparados a partir da imersão dos mesmos em água numa razão de 1:20 (w/v) por 24 h. Todos os extratos afetaram a germinação e crescimento das mudas de mungbean, porem a maior inibição se deu com os estratos aquosos foliares de R. capitata. Uma diminuição linear nas características de germinação do mungbean foi observada com a diminuição na concentração do extrato foliar de 5% para 1%. Os resíduos da R.capitata incorporados pelo solo (1-4%) estimularam o crescimento da raiz e do hipocotil em baixas concentrações, e também inibiram seu crescimento em maiores concentrações.Os resíduos de Rhyncosia capitata incorporados ao solo (4% w/w) reduziram significativamente o índice de vigor das mudas, tendo também um efeito significativo sobre a germinação total. Uma quantidade significativa de ácidos fenólicos solúveis na água foi encontrada nos extratos das plantas de R. capitata. O teor de ácidos fenólicos totais foi mais alto nos extratos foliares do que nos extratos do caule, fruto, ou raiz. Dois ácidos fenólicos, ácido vanílico e acido benzóico (4-hidroximetil), foram encontrados nos extratos foliares de R. capitata.

The Allelopathic Potential of Rosa blanda Aiton on Selected Wild-Growing Native and Cultivated Plants in Europe

“…The germination capacity of Red Fescue and Red Radish seeds was performed by the germination indexes. GP—germination percentage (global method), GI—germination index [ 90 ], MGT—mean germination time [ 5 ], SVI—seedling vigor index for cumulative seeds [ 91 ], CRG—coefficient rate of germination [ 92 ], MGT—mean germination time [ 93 ], RI—allelopathic seeds response [ 94 ]. GP (%) = [number of seeds germinated each day/total number of seeds used in the bioassay] × 100 MGT (day) = ƩDn/Ʃn D—the number of days counted from the beginning of germination, N—number of seeds that appeared on day D GI (%) = [Number of germinated seeds/Days of first count] + [Number of germinated seeds/Days of second count] + … + [Number of germinated seeds/Days of last or final count] CRG (%) = [(n3 + n7)/((n3 × T3) + (n7 × T7))] × 100 n3 and n7 = number of germinated seeds on time T3 and T7, T3 and T7 = 3 and 7 days after germination SVI (a.u.)…”

“…The germination capacity of Red Fescue and Red Radish seeds was performed by the germination indexes. GP-germination percentage (global method), GI-germination index [90], MGT-mean germination time [5], SVI-seedling vigor index for cumulative seeds [91], CRG-coefficient rate of germination [92], MGT-mean germination time [93], RI-allelopathic seeds response [94].…”

“…Their negative impact on the elements of the habitat may be aggravated by secreted allelopathic compounds [2]. When these substances get into the soil, they hinder the growth and development of native species, limiting their occurrence and, thus, biodiversity [3][4][5][6][7]. Allelochemical substances can be present in all parts of plants-roots, rhizomes, stalks, leaves, flowers, fruits, and seeds-and their amount and route of release vary with species [8].…”

Effect of Sorbent Additives to Copper-Contaminated Soils on Seed Germination and Early Growth of Grass Seedlings

“…The germination capacity of grass seeds was evaluated by the germination indexes. Germination percentage—GR (global method) modified because it is calculated after 3 and 7 days of seed germination, for the determination of energy and capacity of germination, speed of emergence—SE [ 90 ], germination index—(GI) [ 91 ], mean germination time—MGT [ 91 ], seedling vigor index—SVI [ 92 ], rate of germination—RG [ 93 ], contamination soil response—RI [ 94 ]. GR (%) = [Number of germinated seeds at 3 (or 7) days × 4] × 100 SE (%) = (Number of germinated seeds at the starting day of germination/Number of germinated seeds at the final days of measurement) × 100 GI (a.u.)…”

Inhibition Activity of Cleome Species Extract on Onion Guest Root

“…Allelopathy plays an important factor in crop productivity. The effect of allelopathy is able to produce and release allelochemicals or phytochemicals to inhibit or stimulate seed germination, seeding growth, shoot, and root growth of other crops [3][4][5].…”