A comparison of callus induction in 4 Garcinia species

Background: This research is intended to determine suitable types and concentrations of plant growth regulators (PGRs) to induce callus on stem and leaf sections of 4 species of the genus Garcinia, namely, Garcinia mangostana, Garcinia schomburgkiana, Garcinia cowa, and Garcinia celebica. The base medium was MS medium containing 30 g l -1 sucrose, 0.5 g l-1 polyvinylpyrrolidone (PVP), and 7 g l-1 agar, and for the different treatments, PGRs were added to the medium as follows: thidiazuron (TDZ) at concentrations of 0, 0.1, 0.5, 1, and 2 mg l-1; 6-(3- hydroxybenzylamino) purine (meta-topolin) at concentrations of 0, 0.5, 2.5, and 5 mg l-1; 4-amino-3,5,6- trichloro-2-pyridinecarboxylic acid (picloram) at concentrations of 0, 0.5, 2.5, and 5 mg l-1; and 2,4- dichlorophenoxyacetic acid (2,4-D) at concentrations of 0, 0.5, 1, 2, and 4 mg l-1. The occurrence of callus was observed after 4 weeks. Results: A maximum of 100% and 93% of G. mangostana leaf explants formed callus in the 0.5 mg l-1 and 1 mg l-1 TDZ treatments, respectively, while 100% of G. schomburgkiana stem explants formed callus in the 1 mg l-1 TDZ treatment and 89% of G. schomburgkiana leaf explants formed callus in the 0.5 mg l-1 picloram treatment. The highest callus induction rate for G. cowa was 62% in the 1 mg l-1 TDZ treatment and for G. celebica was 56% in the 0.5 mg l-1•mT-1 treatment. Conclusions: For all 4 species, the greatest amount of large nodular callus was observed in the TDZ treatments. White, friable callus was observed on most of the 2,4-D and picloram treatment groups. Most meta-topolin treatments resulted in minimal callus formation.

Propagação in vitro de Hypericum cordatum (Vell. ) N. Robson (Clusiaceae) e análise fitoquímica de seus compostos secundários / In vitro propagation of Hypericum cordatum (Vell. Conc. ) N. Robson (Clusiaceae) and phytochemical analysis of its secondary compounds

Hypericum cordatum, planta com possível atividade medicinal foi analisada no presente estudo quanto a sua propagação in vitro e seus principais compostos secundários em comparação com Hypericum perforatum, espécie medicinal utilizada como antidepressivo. Diante das dificuldades que ocorrem na coleta e sua multiplicação por sementes ou via estacas caulinares, iniciou-se a propagação in vitro tendo como resultados: que a indução e o crescimento de brotações foram estimulados pelo regulador 6-benziladenina (2,0 mg L-1), que houve indução de raízes por ácido indol-butírico (0,5 mg L-1), e que as baixas concentrações de auxinas, ácido 2,4-diclorofenoxiacético, ou ácido naftalenoacético (0,01 a 0,4 mg L-1) induziram a formação de calos sendo uma alternativa viável para a multiplicação desta espécie in vitro. Constatou-se com base nas análises bioquímicas e cromatográficas realizadas nesta fase de desenvolvimento das plantas mantidas em culturas in vitro, que as mesmas não contêm hipericina. No entanto, pode-se atribuir o potencial medicinal de H. cordatum às outras substâncias que também possuem importantes atividades biológicas, tais como a xantona e o ácido clorogênico sintetizados nas glândulas foliares de H. cordatum.

Hypericum cordatum, a plant with possible medicinal activity, was analyzed in this study for its in vitro propagation and main secondary compounds, compared to Hypericum perforatum, a medicinal species used as antidepressant. Considering the difficulties that occur in its collection and multiplication through seeds or stem cuttings, in vitro propagation was started and showed the following results: the induction and the growth of sprouts were stimulated by the plant regulator 6-benzyladenine (2.0 mg L-1), there was root induction by indolebutyric acid (0.5 mg L-1) and the low concentrations of auxins, 2,4-dichlorophenoxyacetic acid or naphthaleneacetic acid (0.01 to 0.4 mg L-1) induced callus formation, constituting a viable alternative for the in vitro multiplication of this species. Biochemical and chromatographic analyses carried out at this developmental stage of plants kept in in vitro cultures indicated that they do not contain hypericin. However, the medicinal role of H. cordatum can be attributed to other substances that also have important biological activities, such as xanthone and chlorogenic acid, both synthesized in the leaf glands of H. cordatum.

Efecto de las micorrizas arbusculares sobre el crecimiento y supervivencia de dos especies nativas de la gran sabana, al transplantarlas a un área degradada / Effect of arbuscular mycorrhizas on growth and survival of two plant species indigenous of la gran sabana, transplanted to a degraded area

El propósito de este trabajo fue determinar si la inoculación con hongos micorrízicos arbusculares produce un aumento en el crecimiento y la supervivencia de dos arbustos nativos de La Gran Sabana, al ser transplantados a un área degradada. Semillas pre-germinadas de Clusia pusilla (Clusiaceae) y Gongylolepis benthamiana (Asteraceae) fueron sometidas a dos tratamientos durante una etapa de vivero que se extendió por 5 meses. Dichos tratamientos fueron: M: inoculación con el hongo micorrízico arbuscular Glomus manihotis, junto con la adición de 20 kg.ha-1 de superfosfato triple (SFT) y F: fertilización con 100 kg.ha-1 de SFT. Al final de la etapa de vivero, las plántulas fueron transplantadas a un área afectada por la remoción de la capa superficial del suelo en Luepa, La Gran Sabana. Los resultados obtenidos muestran un comportamiento contrastante entre ambas especies. La inoculación con micorrizas (tratamiento M) produjo un aumento significativo en la supervivencia de C. pusilla, en comparación con el tratamiento donde únicamente se aplicó el fertilizante (tratamiento F). En contraste, la supervivencia de G. benthamiana no se vio afectada por la inoculación con micorrizas. Ambas especies difieren en el tamaño de sus semillas, área foliar específica y relación vástago raíz, aunque son similares en cuanto a la densidad de pelos radicales y el diámetro de sus raíces. Se concluye que C. pusilla es mucho más dependiente de las micorrizas que G. benthamiana y se propone que esa mayor dependencia está relacionada con el menor tamaño de sus semillas en comparación con las de G. benthamiana.

The aim of this work is to evaluate the effect of arbuscular mycorrhizal inoculation on the growth and survival of two species of shrub indigenous of La Gran Sabana, when were transplanted to a degraded area. Pre-germinated seeds of Clusia pusilla (Clusiaceae) and Gongylolepis benthamiana (Asteraceae) were subjected to two different treatments during 5 months in the nursery, before transplanting to the field: F: fertilized with 100 kg.ha-1 of triple superphosphate (TSP) and M: inoculated with the arbuscular mycorrhizal fungus Glomus manihotis, plus 20 kg.ha-1 of TSP. At the end of the nursery stage, seedlings were transplanted to a degraded area situated at Luepa, in La Gran Sabana. Results were contrasting between both species. Arbuscular mycorrhizal inoculation of C. pusilla (M treatment) increased significantly its survival in comparison with treatment F. In contrast, no effect was observed on the survival of G. benthamiana, after AM-inoculation. Both species are different regarding seed weight; specific leaf area and shoot/root relationship but they have no differences respect to hair root density or root diameter. We concluded that C. pusilla is more dependent on mycorrhizas for survival than G. benthamiana. We hypothesized that the higher mycorrhizal dependence showed by C. pusilla is attributable to its smaller seeds in comparison with those of G. benthamiana.