Rodrigo Sobreira Alexandre

Divergência genética entre progênies de maracujazeiro- amarelo com base em características das plântulas

O objetivo do presente trabalho foi avaliar a diversidade genetica entre 24 populacoes de maracujazeiro-amarelo, discriminando os caracteres mais importantes na avaliacao da divergencia genetica, com base em caracteristicas das plântulas. Foram coletadas sementes de frutos obtidos a partir de polinizacao natural de vinte e quatro populacoes segregantes de meios-irmaos de maracujazeiro-amarelo. Utilizou-se delineamento experimental inteiramente casualizado, em vinte e quatro tratamentos (populacoes segregantes), com quatro repeticoes, considerando-se como unidade experimental cada grupo de 50 sementes. Aos 28 dias, avaliaram-se a porcentagem de germinacao e o indice de velocidade de emergencia (IVE). Aos 45 dias, avaliaram-se porcentagem de sobrevivencia, altura das plântulas, comprimento de raiz, numero de folhas e massa da materia seca total das plântulas. Os dados obtidos foram submetidos a analise de variância, e as medias foram agrupadas pelo metodo de Scott & Knott. A diversidade genetica foi estudada de acordo com o metodo de agrupamento de Tocher, baseado na distância de Mahalanobis (D2) e variaveis canonicas. As caracteristicas que mais contribuiram para a divergencia genetica foram porcentagem de germinacao, numero de folhas e IVE. A populacao 20 pode ser recomendada para hibridacao com as outras populacoes devido a sua alta divergencia e tambem altas taxas de germinacao e vigor de sementes.

Influence of the maturity stage and post-harvest storage in germination and initial development processes of yellow passion fruit

The passion fruit is among the main fruit crops cultivated in Brazil. The propagation is predominantly by seeds. Seeds with good quality should be collected at adequate development stage, which can be established according to the fruit maturity stage. The aim of this work was to verify the influence of the fruit maturity stage and the post-harvest storage in the germination and initial development of the seedlings of yellow passion fruit (Passiflora edulis f. flavicarpa). The work was carried out in the Federal University of Vicosa (MG), Brazil. The seeds used were extracted of fruits in three fruit maturity stages (stage 1 - green beginning to alter its fruit epidermis coloration to yellow; stage 2 - fruit with 5 until 50% yellow epidermis coloration and stage 3 - fruit with more than 50% yellow epidermis coloration), and four post-harvest storage periods (0, 3, 6 and 9 days) at room temperature. After, the seeds were sowed in plastic boxes with fine washed sand. The experiment was designed in completely randomized blocks, in a factorial 3 x 4 (maturity stage x post-harvest storage period), with four replications, where each plot was constituted by 50 seeds. It was concluded that, the yellow passion fruit seeds should be extracted at the fruit maturity stages 2 or 3. For the development process of the yellow passion fruit seedlings it was recommended to store the fruits during 3 to 6 days before the seeds extraction.

Metodologia de minienxertia em maracujazeiros

The objective was to evaluate the graft methodology based on cleft grafting on the top of the hypocotyls, using adult minicuttings of apical segments of P. edulis f. flavicarpa, P. edulis, P. alata, P. mucronata and P. foetida, and intermodal of P. mucronata. The experiments were carried out under greenhouse conditions, equipped with intermittent mist irrigation, at Centro Universitario Norte do Espirito Santo (CEUNES), Universidade Federal do Espirito Santo (UFES). The rates of grafting success in combinations of P. edulis f. flavicarpa/P. edulis f. flavicarpa, P. edulis/P. edulis f. flavicarpa, P. alata/P. edulis f. flavicarpa, P. mucronata/P. edulis f. flavicarpa, P. foetida/P. edulis f. flavicarpa were 90, 90, 68, 80 and 90, respectively. The proposed methodology is a novel grafting option for those species of the genus Passiflora.

Effect of synthetic auxins on in vitro and ex vitro bromeliad rooting

The tissue culture can contribute to the propagation of several economic species, such as the bromeliads. This research aimed at evaluating the auxins type and concentration in the in vitro and ex vitro rhizogenesis of Neoregelia concentrica bromeliad. N. concentrica shoots were induced in a growth medium with 15.0 µM of 6-benzylaminopurine, for 80 days, followed by sub-cultivation in phytoregulator-free medium, for 45 days. In the in vitro rhizogenesis, the shoots grew in a medium supplemented with indole-3-butyric acid (IBA) or naphthalene-acetic acid (NAA), at the concentrations of 0.0 µM, 1.0 µM, 2.0 µM, 3.0 µM and 4.0 µM. In the ex vitro rhizogenesis, the bases of shoots were immersed, for 60 minutes, in IBA or NAA solutions, at the concentrations of 0.0 µM, 5.0 µM, 10.0 µM and 15.0 µM. After immersion, the shoots were planted in plastic trays with vermiculite. At the end of each rhizogenesis method, the phytotechnical parameters analysis was carried out. For the in vitro rhizogenesis, a higher number of roots were observed when the shoots were cultivated in concentrations higher than 1.0 µM of NAA, when compared to the IBA. However, the rooting rate differed only at 30 days after the in vitro growth, with a higher root induction in the shoots grown with NAA. At 60 days, the rooting rate was higher than 90% and statistically similar in all treatments. In the ex vitro rhizogenesis, a better formation of the rooting system was observed when 5.0 µ M of IBA was applied, with higher rooting averages and number of roots.

Broccoli production depending on the seed production system and organic and mineral fertilizer

The experiment was conducted in a greenhouse at the Universidade Federal do Espirito Santo, in Alegre, Espirito Santo state, Brazil, to evaluate the broccoli production depending on the seed production system and organic and mineral fertilization. Seeds of the broccoli cultivar Ramoso Piracicaba were originated from lots of seed obtained in an organic and conventional production system. The experimental design was of randomized blocks, with four replications in a factorial arrangement combination of the lots, 2x5 (organic and mineral fertilized seeds) and substrates [S1 (soil + sand + manure), S2 (soil + sand + manure + NPK), S3 (soil + sand + manure + Fertium® 10 g L-1), S4 (soil + sand + manure + Fertium® 30 g L-1) and S5 (soil + sand + manure + Fertium® 50 g L-1]. The analyzed variables were emergency, fresh and dry mass of aerial part, emergency speed and height of seedlings after 28 days of sowing, and plant diameter, leaf area, number of leaves, fresh and dry mass of aerial part, plant height, root volume, fresh and dry root mass, absolute and relative growth rates and increment to leaf area and plant height after 104 days. The emergency was similar in the different substrates; great vigor occurred on conventional seeds; the mineral fertilization increased the production of fresh mass of aerial part; the use of substrate containing soil, sand soil conditioner Fertium (30 to 50 g L-1) increased the volume, fresh and dry mass of roots and rate of increase in these variables.

Enraizamento adventício de estacas do maracujazeiro silvestre Passiflora mucronata Lam.: forma de veiculação e concentrações do ácido indol-3-butírico

Adventitious rooting of wild passionflower Passiflora mucronata Lam. cuttings: vehiculation ways and concentrations of indole-3-butyric acid Passiflora mucronata Lam. is an ornamental, medicinal plant and resistant to bacterial blight on leaves. In addition, it is highly resistant to anthracnose in fruits and branches. The objective of this study was to evaluate the vehicultaion way, liquid or solid, and concentrations of indole-3-butyric acid (IBA) on adventitious rooting of P. mucronatacuttings. The experiment was carried out in a randomized block design in a 2x5factorial design (IBA vehiculation ways: liquid and solid x IBA concentrations: 0; 250; 500; 750 and 1000 mg L -1 for liquid or mg Kg -1 for solid), with four replicates with 16 cuttings each. The characteristics evaluated were rooting (%), root number, longest root length (cm), root volume (cm 3 ) and dry weight of root (g). It was found that the rooting of P. mucronata Lam. does not depend on the way IBA is conveyed, solid or liquid, but the quality of the root system, evaluated by means of the number , volume and dry mass of roots was superior to the one achieved whensolid IBA was used. The behavior of rooting, number and length of roots increased linearly up to the maximum concentration of IBA (1000 mg L -1 or mg Kg -1 ).

Comparison of methods for classification of the coefficient of variation in papaya

The objective of this work was to study the distribution of values of the coefficient of variation (CV) in the experiments of papaya crop (Carica papaya L.) by proposing ranges to guide researchers in their evaluation for different characters in the field. The data used in this study were obtained by bibliographical review in Brazilian journals, dissertations and thesis. This study considered the following characters: diameter of the stalk, insertion height of the first fruit, plant height, number of fruits per plant, fruit biomass, fruit length, equatorial diameter of the fruit, pulp thickness, fruit firmness, soluble solids and internal cavity diameter, from which, value ranges were obtained for the CV values for each character, based on the methodology proposed by Garcia, Costa and by the standard classification of Pimentel-Gomes. The results obtained in this study indicated that ranges of CV values were different among various characters, presenting a large variation, which justifies the necessity of using specific evaluation range for each character. In addition, the use of classification ranges obtained from methodology of Costa is recommended.

Propagação vegetativa de espécies silvestres do gênero Piper, com potencial para uso como porta enxertos em pimenta-do-reino (Piper nigrun)

The establishment of species used as rootstock, which are important in horticulture crop scan may be multiplied, with the aid of growth regulators, by cutting. The objective of this study was to evaluate the influence of IBA on the establishment of native species of the genus Piper with potential use as rootstock of Piper nigrum. Cuttings of P. arboreum, P. amplum and P. sp were treated with different concentrations of IBA (0 ,2000, 4000, 6000 and 8000mg.L-1) and maintained in a greenhouse with intermittent irrigation, with the temperature and humidity controlled. The experimental design was completely randomized in a factorial 3x5 plan (3 Piper species x5 doses of IBA) and comprising of three repetitions per treatment, each plot consisting of 10 cuttings. The evaluation was performed at 45 days of transplanting and the analyzed variables were: survival rate, the number of leaves, the number of shoots and the length of the largest shoot. The Piper arboretum species showed the best growth results for the aerial part independent of the IBA concentration used.

Somatic embryogenesis in Carica papaya as affected by auxins and explants, and morphoanatomical-related aspects

The aim of this study was to evaluate somatic embryogenesis in juvenile explants of the THB papaya cultivar. Apical shoots and cotyledonary leaves were inoculated in an induction medium composed of different concentrations of 2,4-D (6, 9, 12, 15 and 18 µM) or 4-CPA (19, 22, 25, 28 and 31 µM). The embryogenic calluses were transferred to a maturation medium for 30 days. Histological analysis were done during the induction and scanning electron microscopy after maturing. For both types of auxin, embryogenesis was achieved at higher frequencies with cotyledonary leaves incubated in induction medium than with apical shoots; except for callogenesis. The early-stage embryos (e.g., globular or heart-shape) predominated. Among the auxins, best results were observed in cotyledonary leaves induced with 4-CPA (25 µM). Histological analyses of the cotyledonary leaf-derived calluses confirmed that the somatic embryos (SEs) formed from parenchyma cells, predominantly differentiated via indirect and multicellular origin and infrequently via synchronized embryogenesis. The secondary embryogenesis was observed during induction and maturation phases in papaya THB cultivar. The combination of ABA (0.5 µM) and AC (15 g L-1) in maturation medium resulted in the highest somatic embryogenesis induction frequency (70 SEs callus-1) and the lowest percentage of early germination (4%).

Divergência genética em genótipos de maracujazeiro azedo, com base em características físicas e químicas dos frutos

Objetivou-se com o presente trabalho avaliar a divergencia genetica e as caracteristicas fisicas e quimicas de frutos de duas populacoes do maracujazeiro azedo na regiao Norte do Espirito Santo, como as progenies de meio-irmaos de acesso local de um plantio comercial (genotipos: 1; 2; 3; 4; 5; 6; 7; 8; 9 e 10) e do hibrido BRS Ouro Vermelho (genotipos: 11; 12; 13; 14; 15; 16; 17; 18; 19 e 20). A divergencia genetica foi avaliada por procedimentos multivariados como a distância generalizada de Mahalanobis (D2) e pelos metodos de agrupamento de otimizacao de Tocher e UPGMA. Encontrou-se divergencia genetica entre as populacoes estudadas promovendo a formacao de grupos diferentes entre o metodo de Tocher e do UPGMA. As caracteristicas, referentes ao tamanho do fruto, diâmetro polar e equatorial, foram as que mais contribuiram na diversidade genetica dos genotipos. Nas populacoes estudadas de maracujazeiro azedo ha grande variabilidade genetica quanto as caracteristicas avaliadas, o que possibilita selecionar plantas com elevado potencial para fins de melhoramento genetico. O hibrido BRS Ouro Vermelho apresenta boa adaptacao as condicoes locais.