Miranda Titon

Dinâmica do enraizamento de microestacas e miniestacas de clones de Eucalyptus grandis

The aim of this work was to evaluate the dynamics of microcutting and minicutting techniques during rooting process, by monitoring root emergence and development in microcuttings and minicuttings of four Eucalyptus grandis clones. Microcuttings were obtained from in vitro rejuvenated plant-derived sprouts, whereas minicuttings from rooted sprouts derived from plants propagated through conventional cutting technique. The results suggest the greater rooting ability of the microcuttings as compared to the minicuttings, evidenced by the number of roots/cuttings, total root/cutting length, largest root/cutting length, mean length of roots/cutting and dry weight of roots.

Eficiência das minicepas e microcepas na produção de propágulos de clones de Eucalyptus grandis

The objective of this work was to evaluate the efficiency of clonal gardens in the microcutting and minicutting techniques of four Eucalyptus grandis clones regarding the survival, vigor and productive capacity of the microstumps and ministumps in successive collections of microcuttings and minicuttings. The microstumps were obtained from rejuvenated tissue explants through subculture in vitro, and the ministumps by minicuttings derived from conventional rooted cuttings. The ministumps and microstumps of E. grandis exhibited similar performance, i.e., high survival rate, vigor and productive capacity of vegetative propagation material.

Efeito dos reguladores de crescimento dicamba e picloram na embriogênese somática em Eucalyptus grandis

The objective of this paper was to evaluate the effect of dicamba and picloram on the induction of somatic embryogenesis in mature zygotic embryos, cotyledons and hypocotyls of Eucalyptus grandis. Callus induction was obtained in MS culture medium with dicamba (0.25; 0.5; 1.0 and 2.0 mg L-1) or picloram (0.5; 1.5; 5.0 and 10.0 mg L-1). Treatments of cotyledonary explants with dicamba (0.5 mg L-1) or picloram (5.0 and 10.0 mg L-1) resulted in structures similar to somatic embryos, which appeared in different development stages. The histological analysis confirmed the presence of independent structures with an independent vascular system, suggesting that the structures are somatic embryos.

Populações, matrizes e idade da planta na expressão de variáveis físicas em frutos do pequizeiro

Pequi is a very common tree in Central and Center-East Brazilian territory, known as Cerrado sensu strict, and its fruits are largely appreciated by people that live in these regions. This study was proposed due to the lack of information about environmental and genetic effects on physical attributes expression in pequi fruits. Information on this subject is relevant to favor decisions regarding to domestication and breeding processes of this species. Pequi fruits were collected from populations of Curvelo and Sao Goncalo do Rio Preto, State of Minas Gerais, being 15 mother trees per population. These mother trees were selected based on physical attributes that imply their age, being stem diameter at ground level (SD), the main one. Physical attributes were: fruit Total Weight (FTW); Outer Mesocarp Weight (OMW); Putamen Weight per fruit (PW); Putamen Number per fruit (PN) and Pulp Total Weight per fruit (PLTW). There was a mother tree effect for all attributes evaluated, whereas for populations, there was effect only for PN. Correlations among all variables were positive, being some of them significant. Also, correlations between SD and all other variables were positive and some, significant. Results allow the conclusion of high expected gains through vegetative propagation of mother tree selected by means physical fruit attributes: pulp weight can be selected based on putamen weight; the effect of plant age on fruit physical attributes is null or positive, so the selection can be carried out in youth plants.

REDUÇÃO FOLIAR EM MINIESTACAS E MICROESTACAS DE CLONES HÍBRIDOS DE Eucalyptus globulus

The objective of this study was to evaluate the effect of leaf reduction in the rooting of two types of mini-cuttings and micro-cuttings (apical and intermediate) of four hybrid clones of Eucalyptus globulus. Evaluations were performed on the percentage of survival, roots at the lower end of the tube, rooting, height, stem diameter, dry weight of shoot and root. At 90 days, it can be concluded that the apical cuttings with and without leaf reduction were higher than the intermediate cuttings, besides each clone behaved differently in relation to the rooting of mini-cuttungs and micro-cuttings. Vegetative propagation by apical cuttings without leaf reduction can be recommended for the production of seedlings of Eucalyptus urophylla x E. globulus and Eucalyptus grandis x E. globulus.

Effect of Minicutting Length and Leaf Area Reduction on Growth and Nutritional Status of Eucalypt Propagules

Significant improvements to the technique of minicutting Eucalyptus clones have been reported in the literature. However, despite these recent efforts, studies addressing the proper size of minicuttings and the reduction of leaf area have not been well explored. Thus, the present study had the objective of evaluating the effects of the length of the minicuttings and the leaf area reduction on the growth and nutritional condition of Eucalyptus urophylla during propagation. The experiment was conducted for 90 days in the Plantar Reforestation Co. Nursery in the municipality of Curvelo, MG, using a randomized block design with 4 replicates in a factorial arrangement. The effects of 4 lengths of minicuttings (4, 6, 8, and 10 cm), 2 levels of leaf area reductions (0 and 50%), and 2 commercial clones were studied. The length of the minicuttings and the reduction of leaf area did not affect the nutritional status of the leaves, nor did the length affect the quality of the plants at the age of 90 days. The results indicate that it is unnecessary to reduce the leaf area for Eucalyptus propagation.