Efeito de rizobactérias no crescimento inicial e colonização de raízes de alface

Abstract

The lettuce is a hardwood vegetable that stands out because the planting is carried out all year round. However, due to the growing demand for food production, it is necessary to increase the production of lettuce, and with this, several researches are being carried out and one of these methods is the use of rhizobacteria to stimulate their plant development. Organisms selected from the rhizosphere, defined as bacteria with high affinity range, and may be able to perform various activities related to the promotion of plant development. The objective of this work was to evaluate the effect of rhizobacteria in the treatment of lettuce seeds on initial growth and colonization of lettuce roots. The experiments were conducted at the Laboratory of Phytopathology and Soil Microbiology in the years 2017/2018, at the Federal University of Pampa - Campus Itaqui. The experimental design was a completely randomized design with 11 treatments and four replications. The growth promotion test carried out from the treatment of the seeds with the rhizobacteria, where the triple washing of the seeds occurred, then the seeds were added to a bacterial suspension in solution (NaCl 0.85%) and concentration of OD540 = 0 , And was maintained under continuous stirring at 120 rpm for 5 minutes. At the sowing, four seeds were seeded by pots containing substrate. Plant height, number of leaves and dry matter were observed. For root colonization the in vitro test was prepared with test tubes containing agar-water, agar (0.8%), and then autoclaved for 40 min at 120 ° C. For microbiolization, the seeds were placed in a test tube containing agar-water. The tubes were placed in B.O.D. 28 ° C for 7 days. Based on the results it can be concluded that the tested isolates do not promote growth increase of lettuce seedlings and do not colonize the root system in vitro.