Lucas Amaral de Melo

Alterações anatômicas e fisiológicas em Setaria anceps Stapf ex Massey e Paspalum paniculatum L. sob condições de déficit hídrico

Both Setaria anceps (setaria) and Paspalum paniculatum (paspalo) species are tolerant to soil drought water deficiency and flooding. The aim of this work was evaluate anatomical, ecophysiological and metabolic alterations on setaria and paspalo leaves and roots when submitted to soil water deficit conditions. Eleven days after the beginning of water restriction, few variations were observed in density and size of stomata in setaria, but there was decreasing in thickness of mesophyll, vascular bundle, root cortex and transpiration rate. Protein (P), total soluble sugars (AST), reducing sugars (AR) and starch content decreased in leaves and AST and starch content decrease in roots. In paspalo, varations on density and size of the stomatal cells, reduction of the metaxylem diameter and root cortex, increasing of bulliform cells size, leaf concentration of amino acid, AST, AR, and starch were observed.

Enraizamento de miniestacas de clones híbridos de Eucalyptus globulus

The objective of this study was to evaluate the effect of the growth regulator indol butiric acid (IBA) on the rooting of apical and intermediate mini-cuttings of Eucalyptus urophylla x E. globulus and Eucalyptus grandis x E. globulus clones. The mini-cutting rooting was carried out for 30 days in acclimatized greenhouse and after the cuttings were transferred to shade house, where they remained for 10 days. The experimental design was in random blocks with a triple factorial arrangement constituted by two types of mini-cuttings (apical and intermediate), three IBA concentrations (0, 2000 and 4000 mg L -1 ) and eleven clones, in three repetitions, composed of 12 mini-cuttings per repetition. The IBA did not affect the characteristics evaluated. The survival and rooting of apical mini-cuttings were significantly higher. There was significant difference among clones regarding the evaluated variables, except for survival after 30 days in greenhouse.

Anatomia foliar de Tabebuia serratifolia (Vahl) Nich. (Bignoniaceae) propagadas in vitro, in vivo e durante a aclimatização

As mudas propagadas por tecnicas de micropropagacao geralmente apresentam alteracoes significativas induzidas pelas condicoes in vitro, que diminuem a capacidade de sobrevivencia apos a transferencia para o ambiente ex vitro, sendo fundamental a avaliacao da mudanca estrutural durante o processo de adaptacao. Objetivou-se com este trabalho, identificar as diferencas anatomicas foliares entre plantas de Tabebuia serratifolia (Vahl) Nich. (ipe amarelo), cultivadas in vitro, in vivo e durante a aclimatizacao. Foram utilizadas plântulas mantidas por 43 dias em sala de crescimento, com 20, 40, 60 e 80 dias de aclimatizacao e mudas de 90 dias cultivadas em viveiro. As plântulas foram obtidas via cultura de embrioes em meio MS e transplantadas para tubetes contendo plantmax®, para aclimatizacao em viveiro, sob 50% de sombreamento. Nas mesmas condicoes da aclimatizacao, foram produzidas as mudas in vivo. Cortes transversais e paradermicos foram preparados de acordo com tecnicas usuais em microtecnia vegetal. As plântulas in vitro apresentam os tecidos foliares pouco diferenciados e estomatos maiores e mais abertos, exigindo maiores cuidados na etapa inicial de aclimatizacao. Aos 60 dias de aclimatizacao as novas folhas produzidas possuem alguns aspectos anatomicos que podem conferir maior eficiencia fotossintetica e maior capacidade de regulacao hidrica das plantas.

Otimização do tempo necessário para o enraizamento de miniestacas de clones híbridos de Eucalyptus grandis

Each phase in the minicutting process is essential for the success of the seedling production. The objective of this study was to assess the time for rooting in minicuttings of five Eucalyptus grandis hybrid clones and to adjust models that best express the behavior of the genetic materials during the rooting process. The minicutting rooting process was carried out in a acclimatized greenhouse and at three-day intervals, adventitious rooting was evaluated until the 24th day. By the analyses, it was possible to verify peculiarities in relation to the behavior of each clone during the rooting period and to conclude that the necessary time for the process differs among the genetic materials, allowing the identification of the best rooting point of

Enraizamento de estacas lenhosas de espécies florestais

Neste estudo, objetivou-se estudar o potencial de enraizamento de estacas lenhosas de 20 especies florestais nativas. Dois experimentos distintos foram conduzidos. Em ambos, as estacas caulinares apresentavam em media de 15 a 20 cm de comprimento. No primeiro, estacas de nove especies foram selecionadas em quatro classes de diâmetro, com media de 5,0; 9,0; 14,5 e 24 mm. No segundo, estacas de 20 especies foram tratadas com acido indolbutirico (AIB). Cada tratamento foi avaliado em quatro repeticoes com 10 estacas por parcela arranjadas aleatoriamente. Nos dois ensaios, os propagulos foram estaqueados em tubetes preenchidos com vermiculita e casca de arroz carbonizada na relacao 1:1 (v:v). Apos 45 dias em casa de vegetacao, as porcentagens de enraizamento, numero e comprimento de raizes por estaca foram computados. No primeiro experimento, seis apresentaram taxas de enraizamento que variaram de 2 a 88%. Estacas com diâmetro medio de 14,5mm apresentaram melhores resultados em relacao ao enraizamento e a qualidade do sistema radicular. Ja no segundo, nove especies enraizaram e o percentual variou de 0,5 a 88%, sendo que nao foi verificada influencia significativa do tratamento com AIB.

EFFECTIVENESS OF ASCORBIC ACID AND PVP IN THE ROOTING OF CLONAL MINI-CUTTINGS OF Eucalyptus urophylla x Eucalyptus grandis

The objective of this study is to evaluate the effectiveness of the antioxidants ascorbic acid and polyvinylpyrrolidone (PVP) in the rooting of mini-cuttings for three clones of Eucalyptus urophylla x Eucalyptus grandis. Mini-cuttings were gathered from a mini-clonal hedge which had been cultivated in concrete ducts containing washed sand. Five concentrations of each antioxidant were experimentally tested on each of the three clones (C1, C2 and C3). Assessments were done of mini-cutting survival and rooting rates when leaving the greenhouse and the shade house, as well as seedling survival and growth at age 50 days. Ascorbic acid was found to be beneficial to the mini-cuttings of the clone with a lower rooting percentage (C3), whereas PVP was found to be unbeneficial to the clones being studied.

Essential oil content in Eremanthus erythropappus wood powder can be estimated using near infrared spectroscopy

Candeia [Eremanthus erythropappus (DC.) MacLeish], a Brazilian tree species, is being threatened by indiscriminate logging because the essential oil present in its wood has economic importance. The aim of this study was to develop a near infrared spectroscopic model for estimating the essential oil content in E. erythropappus wood to select trees with a high amount of essential oil before harvesting them. Essential oil from 103 wood powders was extracted via hydrodistillation. The values were calculated as the ratio between the mass of essential oil extracted and the oven dry mass of wood, and correlated to the NIR spectra recorded from the wood powders. Statistics associated with the predictive models have demonstrated that NIR has the potential to be a fast and feasible method to replace standard procedures for selecting trees with a high essential oil content. The NIR-based predictions in an independent validation set yielded a high correlation (r = 0.89) with the laboratory-determined values for essential oil content in E. erythropappus wood. This NIR model can be applied to guide wood managers for selecting high-oil-content trees before harvesting them and for developing sustainable strategies for industrial utilisation of Candeia populations.

Estabelecimento in vitro de clones híbridos de Eucalyptus globulus

The present study aimed to evaluate the behavior of Eucalyptus grandis x Eucalyptus globulus and Eucalyptus urophylla x Eucalyptus globulus clones and the effect of different in vitro insertions (at 30, 90 and 150 days after pruning the donor plants) in the in vitro establishment phase. The mini-stump plants, explant providers for the in vitro introductions, were cultivated under an indoor semi-hydroponic clonal mini-hedging. Nodal segment explants of 21 Eucalyptus urophylla x Eucalyptus globulus clones and eight Eucalyptus grandis x Eucalyptus globulus clones were harvested, disinfected and inoculated in an MS culture medium, supplemented with 0.5 mg L-1 of BAP and 0.1 mg L-1 of NAA. After 30 days in culture, evaluations were made and it was concluded that there were variations among the clones, as well as in vitro introductions, for the studied variables, where the in vitro establishment was possible for most clones.

QUALIDADE E CRESCIMENTO INICIAL DE MUDAS DE Mimosa caesalpiniifolia Benth. PRODUZIDAS EM DIFERENTES VOLUMES DE RECIPIENTES

Generally, seedling quality is measured only at the nursery, disregarding the main purpose that is the response of these seedlings after planting the field. The study aimed to evaluate the influence of the container volume in the morphological quality of Mimosa caesalpiniifolia Benth. seedlings in the nursery and its survival and initial growth. Five containers (30, 55, 110, 180 and 280 cm ³) were tested, constituting treatments. At 90 and 120 days after seeding, we evaluated height (H) and stem diameter (DC), dry biomass of shoot (MSA), and root dry biomass (MSR), Robustness Index (H/DC), total dry biomass (MST), the relationship between the shoot and root biomass (RMSAR), root density (DR) and Quality Index of Dickson (IQD). After the last measurement, seedlings were field planted. Evaluations consisted in the survival at 120 days after planting, measuring shoot height, diameter at ground level, and calculated the relative growth. Although the seedlings produced in the three larger containers have shown higher morphological quality values in the nursery, it was found that after planting at field this difference tends to disappear, being possible to produce quality seedlings of Mimosa caesalpiniifolia Benth., able to survive, grow and develop after planting, in any of the tested containers.

ESTAQUIA E EFEITO DA DEFICIÊNCIA HÍDRICA OU INUNDAÇÃO SOBRE CARACTERÍSTICAS MORFOANATÔMICAS DE Cestrum axillare Vell.

The ecosystem of riparian forests has been the subject of numerous studies and research in recent years. However, due to microclimate conditions in these areas, little is known about the species with potential for use in forest restoration projects, since in the same place, it may be conditions of low water availability and floods over a year. Also, the search for alternatives for the planting of seedlings in river borders is essential since it is an enabling environment to erosion, and planting by cuttings is a possibility because there is no need for soil disturbance. Thus, the objective of this study was to evaluate the potential of rooting of stem cuttings of Cestrum axillare Vell. and its morphological and anatomical plasticity in conditions of low availability of water or inundation of root system in order to verify its potential for use in restoration projects in riparian environments. For that, cuttings were made from a matrix plant in different diameter classes and placed to root. After rooted, the plantlets were planted in containers of 4000 cm³ and at four months of age, subjected to low availability of water or flooding of root system. Evaluations were conducted throughout the study, covering visual observation and quantification of morphological and anatomical changes through histological sections. From the results, it was found that Cestrum axillare has potential to be propagated by cutting technique and it is indicated for use in restoration of riparian forest projects.