Aclimatização de amoreira preta-preta cv tupy com rizogenese in vitro e ex vitro sob inoculação de microorganismos promotores do crescimento

Abstract

Aiming at high quality seedlings, micropropagation has established itself as an important technique for seedling production. However, because it is costly, protocols are sought to reduce costs, without loss of quality. As an example, there is the practice of performing rooting and concomitant acclimatization. Therefore, it was sought in this work to evaluate the use of the inoculation of the diazotrophic bacteria Azospirilum brasilense and of the arbuscular mycorrhiza Rhizoglomus clarum in the propagation of blackberry. For this, the experimental design adopted was entirely randomized, in a 2 x 4 factorial scheme. The first factor corresponds to rhizogenesis (in vitro and ex vitro) and the second, the forms of inoculation (control, A. brasilense (AZO), R. clarum (FMA) and coinoculation of these). Initially, in the acclimatization performed in the laboratory, three replicates and five plants per plot were used, where part of these were relocated for acclimatization in a greenhouse, composing a sample of three repetitions with three plants. After 50 days of acclimatization, the FMA showed no differences between the rhizogenesis in the morphological parameters and in ex vitro it was statistically superior to the other treatments in the total fresh mass, total number of leaves and live leaves, length of the root and of the aerial part, with the other inoculations do not differ from the control; in vitro, there was no difference between inoculations. For survival, inoculations averaged 90, 66.67, 70 and 40% for FMA, AZO, FMA + AZO and control, respectively. All inoculations benefited the synthesis of phenolic compounds. As for the enzymatic activity of peroxidase and phenylalanine ammonia, the FMA generated increases in relation to the other treatments, with no differences between the rhizogeneses. After 180 days in the greenhouse, all inoculations were beneficial for improving the photosynthetic apparatus, nutrient content and gains in biomass, and colonization with FMA was also confirmed. Thus, it is concluded that the isolated inoculation of R. clarum can replace rhizogenesis in vitro by ex vitro. Already in the greenhouse, when the plants were in ample growth and greater demand for nutrients and metabolites, all inoculations were beneficial.