The objective of this work was to evaluate the induction of indirect organogenesis by concentrations of dichlorophenoxyacetic acid (2,4-D) and thidiazuron (TDZ) in pitaya (Hylocereus undatus) explants, using scanning electron microscopy and the flow cytometry technique. The treatments consisted of the concentrations of 0, 2.0, and 4.0 mg L-1 2,4-D and TDZ and of the combinations of these regulators. Percentages of callus coverage at 45 and 60 days were evaluated. The explants subjected to the treatments were analized by flow cytometry and scanning electron microscopy. All treatments induced endoreduplication, and there was no somaclonal variation. Under the combination of 2.0 mg L-1 TDZ and 4.0 mg L-1 2,4-D, calluses were formed in 95% of the explants, but were smaller than those produced with 2,4-D separately. The concentration of 2.0 mg L-1 TDZ induces the indirect organogenesis in pitaya explants, confirmed by the presence of conducting vessels through scanning electron microscopy.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
With the increasing demand for pitaya orchard management information to achieve high productivity and commercial quality fruits, liming practice is fundamental since most Brazilian soils are acidic. This study aims to assess lime requirements of Typic Quartzipisamment and Haplorthox soils to calculate tolerated aluminum saturation, desired base saturation, calcium and magnesium requirements to cultivate two pitaya species; Hylocereus undatus and Hylocereus polyrhizus. Two independent experiments were conducted in a greenhouse, organized in a 2 x 4 factorial scheme. Treatments were distributed in randomized blocks with five replications. Treatments of the first experiment corresponded to H. undatus and H. polyrhizus and four lime requirements, 0; 0.8; 1.2 and 1.7 t ha-1 cultivated in Typic Quartzipisamment. Treatments of the second experiment corresponded to H. undatus and H. polyrhizus and four lime requirements, 0; 1.3; 2.0 and 2.8 t ha-1 cultivated in Haplorthox. Shoot and root dry matter, chemical soil attributes and shoot nutrient concentrations were measured. Regression equations were adjusted for each variable, according to the lime requirements of both soils providing the highest dry matter yield in both pitaya species. H. undatus and H. polyrhizus cultivated in Typic Quartzipisamment produced more dry matter when the aluminum saturation was between 13% and 16%, base saturation 70% and the calcium and magnesium requirement 2.5 cmolcdm-3. H. undatus and H. polyrhizus cultivated in Haplorthox produced more dry matter when the aluminum saturation was between 1% and 4%, base saturation between 55% and 70%, and calcium and magnesium requirement 3.0 cmolcdm-3.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.