RESUMEN

Endogenous free polyamines (PAs), putrescine, spermidine and spermine, from developing fruitlets of Citrus species (Citrus unshiu Marc. and Citrus clementina Hort ex Tanaka) which differ in their parthenocarpic ability, and from uniflowered leafy and leafless inflorescences differing in their ability to set, have been determined by dansylation and separation of dansyl derivatives by HPLC. No significant differences in PAs content were observed between species or between leafy and leafless inflorescences which, nevertheless, significantly differed in fruit set. However, significant differences in their content were found in developing fruitlets, depending on the preceding flowering intensity of the tree and on the fruitlet load. These results suggest that, in Citrus, PAs may act as a nitrogen source rather than a regulator of fruit set.

Asunto(s)

RESUMEN

This study was carried out in Alcanar (Tarragona - Spain) to evaluate the effect of five indolebutyric acid (IBA) concentrations (0.0; 0.5; 1.0; 1.5; 2.0 g/L) and inoculation with arbuscular mycorrhizae fungi (AMF) (Glomus intraradices Schenck & Smith) on Carrizo citrange (Citrus sinensis (L.) x Poncirus trifoliata (L.) Raf.) vegetative development, P and K foliar contents and root morphology. The experimental design was in a Completly Randomized Block Design with 10 seedlings per plot and 4 replicates. The IBA concentrations had no effect on vegetative development of nonmycorrhizal seedlings, althougt it had increased P and K foliar contents and primary xylem tickness. AMF increased P foliar content. IBA x AMF interaction was observed, increasing IBA concentrations on mycorrhizal seedlings resulted in increased in vegetative development, P and K foliar contents and primary xylem thickness.

Este estudo foi realizado na localidade de Alcanar (Tarragona, Espanha) e objetivou avaliar o efeito de cinco concentrações do ácido indolbutírico (AIB) (0,0; 0,5; 1,0; 1,5; 2,0 g/L) e da inoculação com micorrizas arbusculares (MA) (Glomus intraradices Schenck & Smith) sobre o desenvolvimento vegetativo, conteúdo foliar de P e K e morfologia radicular de plântulas de citrange Carrizo (Citrus sinensis (L.) X Poncirus trifoliata (L.) Raf.). Utilizou-se o delineamento experimental de blocos completos casualisados em esquema fatorial, com 4 repetições e 10 plantas por parcela. A aplicação de AIB não alterou o desenvolvimento vegetativo das plântulas cultivadas em ausência de MA, apesar de haver incrementado a quantidade de P e K e a espessura dos feixes vasculares. As MA incrementaram o conteúdo de P foliar. Encontrou-se uma interação positiva entre o AIB e as MA, pois as plântulas micorrizadas apresentaram um incremento no desenvolvimento vegetativo, nos conteúdos foliares de P e K e na espessura dos feixes vasculares com o aumento das concentrações de AIB.

RESUMEN

This study was carried out in Alcanar (Tarragona - Spain) to evaluate the effect of five indolebutyric acid (IBA) concentrations (0.0; 0.5; 1.0; 1.5; 2.0 g/L) and inoculation with arbuscular mycorrhizae fungi (AMF) (Glomus intraradices Schenck & Smith) on Carrizo citrange (Citrus sinensis (L.) x Poncirus trifoliata (L.) Raf.) vegetative development, P and K foliar contents and root morphology. The experimental design was in a Completly Randomized Block Design with 10 seedlings per plot and 4 replicates. The IBA concentrations had no effect on vegetative development of nonmycorrhizal seedlings, althougt it had increased P and K foliar contents and primary xylem tickness. AMF increased P foliar content. IBA x AMF interaction was observed, increasing IBA concentrations on mycorrhizal seedlings resulted in increased in vegetative development, P and K foliar contents and primary xylem thickness.

Este estudo foi realizado na localidade de Alcanar (Tarragona, Espanha) e objetivou avaliar o efeito de cinco concentrações do ácido indolbutírico (AIB) (0,0; 0,5; 1,0; 1,5; 2,0 g/L) e da inoculação com micorrizas arbusculares (MA) (Glomus intraradices Schenck & Smith) sobre o desenvolvimento vegetativo, conteúdo foliar de P e K e morfologia radicular de plântulas de citrange Carrizo (Citrus sinensis (L.) X Poncirus trifoliata (L.) Raf.). Utilizou-se o delineamento experimental de blocos completos casualisados em esquema fatorial, com 4 repetições e 10 plantas por parcela. A aplicação de AIB não alterou o desenvolvimento vegetativo das plântulas cultivadas em ausência de MA, apesar de haver incrementado a quantidade de P e K e a espessura dos feixes vasculares. As MA incrementaram o conteúdo de P foliar. Encontrou-se uma interação positiva entre o AIB e as MA, pois as plântulas micorrizadas apresentaram um incremento no desenvolvimento vegetativo, nos conteúdos foliares de P e K e na espessura dos feixes vasculares com o aumento das concentrações de AIB.