Impedimento físico do crescimento radicular de bananeiras cultivadas in vitro

Abstract

Oxygen deficiency conditions caused by soil compaction can be simulated in vitro. The increasing Phytagel concentration in the culture medium can lead to anoxia in the root environment conditions allowing the study of the cultivars of banana under this condition. The objective of this study was to evaluate the cultivars Grande Naine, Vitória and Princesa have photosynthetic capacity and vegetative growth correlated to those presented in the field, as well as select cultivars tolerant to soil compaction condition. In the test tube was placed the same culture medium at the top standard culture medium with the dosage of 1.8 g L-1 and the lower layer Phytagel , 1.8; 2.8; 3.8; 4.8 and 5.8 g L-1 Phytagel. The experiment was carried out and analyzed in a completely randomized design. For the analysis of gas exchange scheme was 3 x 5 factorial (3 cultivars and five doses of Phytagel). For growth analyzes the scheme was in split-plot in time, in the main plots were evaluated three cultivars of bananas (Grande Naine, Vitória and Princesa). The subplot consisted of five doses of Phytagel (1.8, 2.8, 3.8, 4.8 and 5.8 g L-1) and the sub-subplots of the three evaluation periods (10, 20 and 30 days after inoculation of the explant in culture medium). It was concluded that the behavior of the cultivar Grand Naine, Cavendish , in vitro correlates with its greatest force behavior compared cultivars of Silver and Apple subgroup field. This is evidence that it was possible to extrapolate the test field for controlled laboratory conditions. The cultivar Vitória is recommended as the most tolerant in compacted soil conditions, this result was of great importance for the genetic improvement of crops.