Inoculação de rizobactérias em sementes e plântulas para produção de mudas de guaranazeiro

Abstract

The guaraná tree (Paullinia cupana var. sorbilis (Mart.) Ducke) is a native species of the Amazon region with high caffeine concentration and economic potential for Amazonas State. There are cultivars developed by Embrapa with resistance to pests and diseases, good adaptability and productivity. These cultivars and their interactions with soil microorganisms are important, especially in the seedling production process. The beneficial relationships between plant and microorganisms are related to the biosynthesis and supply of growth stimulator substances may result in shortening the cycle plant yatchery or increasing in productivity. Thus, this research has the objective to evaluate the potential of rhizobacteria promotors of growth on rooting of guarana plants. The experimental research was completely randomized block design with four repetitions in a 2x2 factorial + 2, where the factors are: two cultivars of guarana tree (BRS-Amazon and BRS-Maués), two rhizobacteria (Burkholderia ambifaria and Bacillus sp.) And more two witnesses, one for each cultivar. At 180 days after sowing, the seedlings were taken from the plastic bags, separating the root system of the plant canopy, and measured the length of roots, volume, shoot dry mass, height, number of leaves, leaf area and shoot dry mass, determined the carbohydrate content, proline and shoot nutrients. The rhizobacteria did not influence the growth of seedlings, however, the levels of carbohydrates and nutrients were higher when there was inoculation of rhizobacteria, and the bacterium Burkholderia ambifaria cultivar BRS the best results. Proline contents were higher in the control treatment of both cultivars.