Fernando Grossi

Estabelecimento, multiplicação e alongamento in vitro de Eucalyptus benthamii Maiden & Cambage x Eucalyptus dunnii Maiden

Neste trabalho foram testadas diferentes concentracoes de cloro ativo (NaOCl) na assepsia de explantes para o estabelecimento in vitro, bem como benzilaminopurina (BAP) e acido naftalenoacetico (ANA) para a multiplicacao e alongamento de Eucalyptus benthamii x Eucalyptus dunnii. As minicepas fornecedoras de propagulos para introducao in vitro foram conduzidas em minijardim clonal sob sistema semi-hidroponico. Segmentos nodais dos clones H12, H19 e H20 foram desinfestados com 0,5; 1,0; 1,5; e 2,0% (v/v) de cloro ativo durante 10 min e inoculados em meio de cultura MS. Na obtencao de brotacoes multiplas, utilizou-se o meio de cultura ½MS suplementado com 0; 0,25; 0,50; 0,75; e 1,0 mg L-1 de BAP. Na fase de alongamento, utilizou-se o meio de cultura ½MS com 0; 0,25; 0,50; 0,75; e 1,0 mg L-1 de ANA. Nao houve interacao entre os fatores estudados, obtendo-se 45%, 46% e 66% de estabelecimento do clone H12, H19 e H20, respectivamente. A concentracao de BAP que resultou na maior proliferacao de gemas axilares para o clone H12 aos 60 dias foi estimada na faixa de 0,25 e 0,30 mg L-1. Aos 60 dias, a faixa entre 0,25 e 0,75 mg L-1 de ANA promoveu o maior numero de brotacoes alongadas do clone H12.

Miniestaquia de Eucalyptus benthamii × Eucalyptus dunnii : (II) sobrevivência e enraizamento de miniestacas em função das coletas e estações do ano

This study aimed to evaluate, throughout the seasons, the minicutting technique as a cloning method for Eucalyptus benthamii x Eucalyptus dunnii hybrids regarding minicutting survival and rooting. The ministumps of H12, H19 and H20 clones were cultivated during 352 days in a clonal minigarden in a semi-hydroponic system in a sand bed, where the nutritive solution was supplied by drip irrigation. During the experiment, 27 successive minicutting samplings were performed in 4 seasons of the year: spring, summer, autumn and winter. The minicutting basal portion was immersed in hydro-alcoholic solutions containing 2,000 mg L -1 of IBA during 10 seconds. The experiment was conducted using an entirely randomized design with 5 replications and 20 minicuttings per replication. The minicutting rooting varied in function of the clone and presented high sensitivity to seasonal and temperature variations. The best rooting indices occurred in the cooler seasons (19.59% to 56.20%) and the lowest in warmer seasons (4.62% to 8.50%). The H19 and H20 clones presented the greater indices for rooting in all 4 seasons.

Efeito da dose de nitrogênio e de formulações de substratos na miniestaquia de Eucalyptus dunnii maiden

The aim of this study was to determine the influence of different nitrogen doses and substrate formulations on the minicutting technique of Eucalyptus dunnii Maiden. The clonal minigarden of 90-day- old seedlings was cultivated in the commercial substrate of pine bark and vermiculite (tubes of 55 cm3). The dose test used a unique source (NH4NO3) in the following concentrations of N: 0.2; 0.4 and 0.6 g L- 1. Each ministump was weekly watered with 10 mL of the tested solution. Five different substrate mixtures were tested: a commercial substrate with pine bark special, medium size vermiculite, carbonized rind of rice and incorporated fertilization. The survival of ministumps in the nitrogen doses tested was 100% until the 10th collection, after which, it was observed mortality in 0.4 treatment (1 ministump). All the evaluated characteristics showed direct relation to the N doses tested. The higher values were achieved with higher doses. The substrates presented statistical differences in the survival and formation of seedlings (collar diameter and height) and vegetative vigor of seedlings. In conclusion, the minicutting technique of E. dunnii is influenced by the nitrogen fertirrigation and the substrate. It is suggested the dose of 0.6 g L-1 and the substrate formed by the commercial substrate with pine bark and vermiculite + medium size vermiculite + carbonized rind of rice (1:1:1) + incorporated fertilization.

MINIESTAQUIA DE Eucalyptus benthamii × Eucalyptus dunnii: ( I ) SOBREVIVÊNCIA DE MINICEPAS E PRODUÇÃO DE MINIESTACAS EM FUNÇÃO DAS COLETAS E ESTAÇÕES DO ANO

This study aimed to evaluate, throughout the seasons, the mini-cutting technique as cloning method for Eucalyptus benthamii × Eucalyptus dunnii hybrids regarding to the mini-stumps survival and to the mini- cuttings production. The ministumps of H12, H19 and H20 clones were cultivated during 352 days in a clonal mini-garden under semi-hydroponic system in a sand bed, where the nutritive solution was supplied by drip irrigation. During the experiment, 27 successive mini-cuttings samplings were performed in four seasons of the year: spring, summer, autumn and winter. The experiment was conducted under whole a randomized design with five replications and four mini-stumps per replication. After 27 successive mini- cuttings samplings, the mini-stumps presented high survival percentage (89.68%), which indicated their high longevity as sprouts supply sources. The mini-cuttings production varied in function of the clone and presented a high sensitivity of seasons and temperature variations. The highest mini-cutting production occurred in warmer seasons (spring and summer), with 635.42 until 852.64 mini-cuttings m-2 variation, and the lowest in the cooler seasons (autumn and winter), with 592.38 until 629.36 mini-cuttings m-2 variation. The mini-cutting annual production was 18,934.76; 20,942.27 and 20,748.14 mini-cuttings m-2 year-1 for H12, H19 and H20 clones, respectively.

Phosphorus nutrition in the growth of Bauhinia forficata L. seedlings

One of the greatest problems in the elaboration of forestation programs using native species is the lack of knowledge about seedling production. This study aimed to evaluate the growth of Bauhinia forficata seedlings submitted to phosphorus levels. Elevenday-old seedlings were transplanted to small tubettes (110 cm3) with pinus bark and vermiculite substratum base. The experiment was conducted in an entirely randomized delineation, with six P treatments: TO-control (substratum without P addition), T1-50, T2100, T3-150, T4-200 and T5-250 mg dm-3, with five replications and 20 seedlings per replication. After 60 days, the seedlings presented a 98.2% survival rate and good root formation. The height varied in function of P levels, with maximum production up to the P dose of 250 mg dm-3; 60 days after the transplant, similar behavior for leaf area and dry matter production was observed. Furthermore, the P incorporation increased the phosphorus (P), potassium (K) and nitrogen (N) accumulation in vegetable tissues. Seedling growth was positively influenced by P levels, and the maximum growth occurred up to the P dose of 250 mg dm-3. In conclusion, this characteristic showed that the species requires high levels of P during initial growth, under the tubette system.

Seed development of Chrysophyllum gonocarpum (MART. & EICHL.) ENGL. (SAPOTACEAE)

The object of this study was to describe the embryo, endosperm and integument development of Chrysophyllum gonocarpum (Mart. & Eichl.) Engl. seed. The ovule is hemitropous, with embryo development being of the Caryophyllad type and the endosperm of the Nuclear type. The mature embryo presents a short and cylindrical hypocotyl-radicle axis with foliaceous cotyledons. The mature seed stores aleurone grains and lipids in the cotyledons and in the remaining endosperm cells. The exotesta is composed of several layers of sclerenchymatous cells, also present in the hilum region. This exotesta feature is registered for the first time in Chrysophyllum seeds and might have ecological and taxonomic implications.

Adubação fosfatada no crescimento de mudas de Bauhinia forficata L

One of the greatest problems in the elaboration of forestation programs using native species is the lack of knowledge about seedling production. This study aimed to evaluate the growth of Bauhinia forficata seedlings submitted to phosphorus levels. Elevenday-old seedlings were transplanted to small tubettes (110 cm3) with pinus bark and vermiculite substratum base. The experiment was conducted in an entirely randomized delineation, with six P treatments: TO-control (substratum without P addition), T1-50, T2100, T3-150, T4-200 and T5-250 mg dm-3, with five replications and 20 seedlings per replication. After 60 days, the seedlings presented a 98.2% survival rate and good root formation. The height varied in function of P levels, with maximum production up to the P dose of 250 mg dm-3; 60 days after the transplant, similar behavior for leaf area and dry matter production was observed. Furthermore, the P incorporation increased the phosphorus (P), potassium (K) and nitrogen (N) accumulation in vegetable tissues. Seedling growth was positively influenced by P levels, and the maximum growth occurred up to the P dose of 250 mg dm-3. In conclusion, this characteristic showed that the species requires high levels of P during initial growth, under the tubette system.

Phosphorus nutrition in the growth of Bauhinia forficata L. seedlings - DOI: 10.4025/actasciagron.v30i5.787

One of the greatest problems in the elaboration of forestation programs using native species is the lack of knowledge about seedling production. This study aimed to evaluate the growth of Bauhinia forficata seedlings submitted to phosphorus levels. Elevenday-old seedlings were transplanted to small tubettes (110 cm3) with pinus bark and vermiculite substratum base. The experiment was conducted in an entirely randomized delineation, with six P treatments: TO-control (substratum without P addition), T1-50, T2100, T3-150, T4-200 and T5-250 mg dm-3, with five replications and 20 seedlings per replication. After 60 days, the seedlings presented a 98.2% survival rate and good root formation. The height varied in function of P levels, with maximum production up to the P dose of 250 mg dm-3; 60 days after the transplant, similar behavior for leaf area and dry matter production was observed. Furthermore, the P incorporation increased the phosphorus (P), potassium (K) and nitrogen (N) accumulation in vegetable tissues. Seedling growth was positively influenced by P levels, and the maximum growth occurred up to the P dose of 250 mg dm-3. In conclusion, this characteristic showed that the species requires high levels of P during initial growth, under the tubette system.