Telde Natel Custódio

Diferentes suplementos no cultivo in vitro de embriões de pinhão-manso

The objective of this work was to evaluate the influence of maturation stages of physic nut fruits on the development of their embryos cultivated in MS medium supplemented with sucrose, coconut water and activated carbon. Fruits were collected, and their embryos were extracted aseptically. They were submitted to two experimental conditions: embryos from fruits in three development stages (immature, mature and dry) were put into MS medium, supplemented with sucrose (0, 15, 30 and 60 g L-1); embryos derived from dry fruits were put into MS medium supplemented with sucrose 30 g L-1, activated carbon (0, 1, 2 and 3 g L-1), and coconut water (0, 50, 100, 150, 200 e 250 mL L-1). Explants were kept in a growth chamber under controlled conditions during 30 days. Only the zygotic embryos from immature fruits needed sucrose supplementation in the culture medium to sustain germination. Better embryos development occurs in MS medium supplemented with 60 g L-1 of sucrose. The association of activated carbon and coconut water provides better growth of seedlings derived from embryos extracted from seeds of dry fruits.

Ecofisiologia da germinação de sementes de Campomanesia pubescens

The gabiroba bush [Campomanesia pubescens (DC.) O. Berg. (Myrtaceae)], a native species of the Cerrado is considered a plant with melliferous, ornamental and medicinal potential. Aiming to evaluate the influence of abiotic factors on seed germination, two experiments were conducted. The first was conducted in a completely randomized design in a factorial design(4x3x2), composed of four temperatures (15-25, 20-30°C alternate, 25 and 30°C constant), 3 substrates (paper, sand and vermiculite) and two light conditions (light and dark). The second experiment aimed to evaluate the tolerance to desiccation of fresh seeds dried superficially, with 35% of water, by drying it in oven with forced ventilation of air at 30°C for 30, 60, 90, 120, 150, 180, 260, 360, 750 and 810 minutes. To evaluate the physiological quality of seeds gabiroba, shrub planting on paper, in the dark and 30°C, enables a better expression of the force. The seeds of bush gabiroba are intolerant to desiccation and can be classified as recalcitrant.

Caracterização morfoagronômica e coeficientes de trilha de caracteres componentes da produção em mandioca

The objectives of this work were to perform the agronomic characterization of 100 cassava plants (Manihot esculenta Crantz) and to obtain path coefficients analysis between the storage root production (basic variable) and five production components (explanative variable). The experiment was conducted at a research farm of Universidade Federal de Lavras, Minas Gerais State, Brazil, in square lattice (10x10), with two replications, using 100 clones and four plants per plot. Statistical analyses were accomplished considering the eight characteristics individually. The Scott-Knotts test was used for grouping the means. Clones 87 and 88 showed to be promising both to be used in crossings and to be fixed as new cultivate, due to their excellent performance in the characteristics: length, number and storage roots production per plant. Path coefficient analysis demonstrates that root number per plant and aerial part weight can be used as criteria of indirect selection for storage roots production.

Modelos de predição para sobrevivência de plantas de Eucalyptus grandis

Objetivou-se com este trabalho comparar modelos de predicao de plantas sobreviventes de Eucalyptus grandis. Utilizaram-se os seguintes modelos: modelo linear misto com os dados transformados, utilizando-se as transformacoes angular e BOX-COX; modelo linear generalizado misto com distribuicao binomial e funcoes de ligacao logistica, probit e complemento log-log; modelo linear generalizado misto com distribuicao Poisson e funcao de ligacao logaritmica. Os dados sao provenientes de um experimento em blocos ao acaso, para avaliacao de progenies maternas de Eucalyptus grandis, aos 5 anos de idade, em que a variavel resposta sao plantas sobreviventes. Para comparacao dos efeitos entre os modelos foram estimadas as correlacoes de Spearman e aplicado o teste de permutacao de Fisher. Foi possivel concluir que, o modelo linear generalizado misto com distribuicao Poisson e funcao de ligacao logaritmica se ajustou mal aos dados e que as estimativas para os efeitos fixos e predicao para os efeitos aleatorios, nao se diferenciaram entre os demais modelos estudados.