Giulio Cesare Stancato

Germinação de sementes e formação de mudas de Caesalpinia echinata Lam. (Pau - Brasil): efeito de sombreamento

Caesalpinia echinata Lam. (Brazilwood), Brazils national tree, has ornamental potential, and due to years of exploitation this species has been reduced on the verge of extinction. This study was aimed to evaluate seed germination and seedling growth of brazil wood under shading conditions. The experiments were conducted at the IBt/SMA Ornamental Department, Sao Paulo-SP. Seeds were harvested from ripe fruits, from trees of the experimental arboretum of brazilwood at Mogi-Guacu-SP. The germination tests were carried out in 1999, 2000 and 2003 with 4 replicates consisting of 25 seeds, the germination percentage and the speed germination index (SGI), subjected to five shading levels (0%, 20%, 40%, 60%, 80%) were evaluated. Nine-month-old brazilwood seedlings were submitted to the same shading treatments and the analyzed variables were seedling heights, stem base diameters and number of leaves. The experimental design was completely randomized with four replicates, and each experimental unit consisted of 24 plants, totaling 96 plants. The obtained results showed that shading levels did not the affect seed germination percentage and SGI. The stem base diameters were not statically significant for full sunlight, 20 and 40% of shading, but they were significant for the treatments with 60 and 80% of shading.

Crescimento de orquídeas epífitas in vitro: adição de polpa de frutos

THE PULPS OF FRUITS IN THE GROWTH OF EPIPHYTIC ORCHIDS This work was carried out with the aim of studying the effect of pulp of fruits on the growth of orchids seedlings in vitro . Three species of epiphytic brazilian orchids were used: Laelia longipes Rchb.f., Laelia tenebrosa Rolfe e Miltonia spectabilis (Lindley). The following nutritive media were tested: 10:10:10 (N:P:K), at 1 gL -1 , 10:30:20 at 1 gL -1 , apple pulp, at 10 gL -1 , tomato pulp at 10 gL -1 , banana pulp at 50 gL -1 , and also the KNUDSON, VACIN and WENT, MURASHIGE and SKOOG (MS) media. In seedlings of L. Longipes cultivated in 10:10:10 and banana pulp was observed higher accumulation, and the lowest one in MS. Analysis of dry mass results for Miltonia spectabilis showed that the media 10:30:20 and banana pulp propiciated the highest dry mass accumulation and the MS medium, the lowest. In decreasing order of total dry mass accumulation are the media 10:30:20 and banana pulp, followed by 10:10:10, tomato pulp, KNUDSON (58,3%), VACIN e WENT (18,7%), apple pulp (13,2%) and MS (4,1%). For Laelia tenebrosa, seedlings cultivated in banana pulp incorporated higher dry mass content, followed by those cultivated in 10:10:10, whereas the remaining media propitiated reduced accumulation.

Associação de fungos micorrízicos arbusculares e cultivares micropropagadas de antúrio

One of the most important steps on micropropagated Anthurium plantlets is the acclimatization. Mycorrhization could be a process that helps the plantlets to change to the autotrophic state. The objective was to evaluate the effect of the mycorrhizal association on the growth of Anthurium cultivars. A experiment was conducted under greenhouse conditions, using the cultivars IAC Astral, IAC Eidibel, IAC Jureia, IAC Luau, IAC Netuno and IAC Omega and the arbuscular mycorrhizal fungi Glomus intraradices, Glomus etunicatum and Acaulospora sp., in organic substrate, at the plantlets acclimatization stage. The results showed that there was increase in shoot dry matter in mycorrhizal plantlets and that the symbiotic efficiency varied according to the cultivar and arbuscular mycorrhizal fungus.

Micorrização e adubação de mudas micropropagadas de antúrio, cv. Eidibel: crescimento e aclimatização ex vitro

Para a formacao de mudas, plântulas micropropagadas de anturio sao submetidas a uma das etapas mais criticas na cultura de tecidos de plantas que e da transferencia in vitro para ex vitro. O emprego de fungos micorrizicos arbusculares (FMA) que possam promover maior crescimento e sobrevivencia da plântula micropropagada pode ser promissor e viavel para plantas produzidas em ambiente protegido. O objetivo foi monitorar as respostas fisiologicas das plântulas de anturio cv. Eidibel sob influencia de adubacao N:P:K e/ou inoculacao de Glomus intraradices. Em uma primeira fase, as plântulas in vitro foram transferidas para bandejas de polipropileno, contendo um substrato a base de casca de Pinus, realizando-se os tratamentos: controle, adubacao (Osmocote 15:10:10), inoculacao de FMA e adubacao, e somente inoculacao. As plântulas permaneceram durante 100 dias, quando foram transplantadas para vaso de 1 L, contendo o mesmo substrato. As plântulas do controle foram divididas nos tratamentos: controle/controle, controle/adubacao, controle/adubacao e inoculacao e controle/inoculacao, enquanto as plântulas dos demais tratamentos da primeira fase permaneceram da mesma forma. Nesta fase, permaneceram por 450 dias, determinando-se: materia seca da parte aerea, da raiz, da folha e total, area foliar, relacao parte aerea/raiz, relacao materia seca/materia fresca total e colonizacao micorrizica. A micorrizacao das plântulas micropropagadas de anturio, tanto na fase de aclimatizacao quanto de obtencao de mudas, nao atingiu o mesmo efeito positivo da adubacao N:P:K na promocao do crescimento.

Efeitos de nitrogênio, fósforo e potássio no crescimento de Rhapis excelsa (Thunberg) Henry ex. Rehder (Palmeira-Ráfia)

Rhapis excelsa e uma das palmeiras ornamentais mais cultivadas no mundo, indicadas principalmente para vasos e areas de sombra. A maioria das palmeiras apresenta crescimento lento. O objetivo deste estudo e acelerar o processo de producao de mudas. Analisaram-se os efeitos da adubacao realizada com nitrogenio, fosforo e potassio, sob o crescimento da especie, ao longo de 8 meses. As mudas com altura de 3,80 cm foram plantadas em substrato constituido de partes iguais de terra e vermiculita. Realizaram-se aplicacoes semanais de NPK, diretamente no solo, na concentracao de 10 mg.L-1 de substrato, utilizando-se como fonte: MAP (P), sulfato de amonio (N) e cloreto de potassio (K). Os tratamentos foram constituidos de todas as combinacoes possiveis destes nutrientes, mais uma testemunha. O experimento foi mantido em casa-de-vegetacao com nebulizacao. Avaliaram-se os resultados com base na producao de materia seca da parte aerea e das raizes, area foliar, diâmetro do caule, numero de folhas e altura do estipe. O nutriente que proporcionou um maior desenvolvimento e crescimento da palmeira Rhapis excelsa foi o nitrogenio, influenciando de forma positiva na maioria dos parâmetros analisados. Verificou-se melhor desenvolvimento das mudas com a aplicacao de N, independente da combinacao com P e ou K.

Rhipsalis grandiflora Haw. (Cactaceae) propagation by setem cuttings

The genus Rhipsalis is being cultivated as a potted plant since the view of the pendant branches with coloured flowers and fruit is very appreciated. Considering that there is no information about the production of rooted propagules of these species, the goal of this work was to evaluate the development of stem cuttings, stimulated by the application of plant growth regulators. The indolebutyric acid (IBA) was tested at 0; 4.07; 5.81, and 11.63 mmol L-1 and the naphthaleneacetic acid (NAA) at 0; 4.53; 6.47, and 12.94 mmol L-1 for their activity in promoting roots on apical stem segments of Rhipsalis grandiflora Raw. The base of stem cuttings was dipped into auxin solutions mixed with talc and each one was partially embedded in fir bark (Pinus sp) and fern fiber (1:1) in polystyrene propagation flats, placed throughout the rooting period in a greenhouse (50% shading), at 60-90% of relative humidity and temperatures from 20 to 25oC. The experimental design was a completely randomised with eight treatments (twelve replicates), with samplings at 0; 20; 50; 80, and 150 days. The results indicate no differences between IBA and NAA regarding the dry mass of roots, but an increase in for concentrations of 0 and 4.07 mmol L-1 of IBA and 0 and 4.53 mmol L-1 of NAA, in relation to treatments with auxins. Stem cuttings treated with 4.07 mmol L-1 of IBA and 4.53 mmol L-1 of NAA, had greater dry mass of shoot bud differentiation in relation to those treated with 0 mmol L-1.

Anthurium growth responses to phosphate fertilisation and inoculation with an arbuscular mycorrhizal fungus

Summary We evaluated the effects of inoculation with an arbuscular mycorrhizal fungus (AMF) and phosphate fertilisation on the growth of commercial anthurium (Anthurium andraeanum Linden ex André, ‘Eidibel’) plantlets in a greenhouse experiment. We subjected the plantlets to the following treatments in a 3 × 4 factorial design: three AMF inoculation treatments [i.e., non-inoculated (NM) plantlets, or plantlets inoculated with Glomus intraradices Schenck & Smith (GI) or G. etunicatum Becker & Gerd. (GE)] and four rates of P fertiliser (5, 10, 15, or 30 mg l–1). Inoculation with G. intraradices or G. etunicatum promoted plantlet growth at all rates of P application, except 30 mg l–1, with average dry weights (DWs) of 0.68 ± 0.19 g in NM, 1.08 ± 0.44 g in GI-inoculated, and 1.32 ± 0.51 g in GE-inoculated plantlets. Inoculation with either AMF also increased shoot DWs, leaf areas, and shoot P concentrations. Increasing the rate of P application decreased the efficiency of symbiosis (ES; measured as the relative increase in DW) in GI-inoculated plantlets (ranging from 63.9% to 27.8%, with an average of 51.6%), but both the lowest and the highest rates of P application resulted in relatively high ES values (61.0% and 61.4%, respectively; ranging from 43.8% to 61.4% with an average of 55.6%) in GE-inoculated plantlets. Our results demonstrate that inoculation with either AMF significantly increased shoot P concentrations in A. andraeanum plantlets, which may reduce the need for the application of P fertiliser during greenhouse production.