ISOLATION AND CHARACTERIZATION OF PLANT GROWTH PROMOTING BACTERIA ISOLATED FROM GARLIC (allium sativum).

Abstract

-Garlic has great economic and social importance in Santa Catarina. It is a demanding crop in nutrients, being necessary high amount of chemical fertilizers, increasing the cost of production and the environmental impact. An alternative to the use of inputs are Rizobacteria Promoting Plant Growth (RPCP). Among the RPCPs, the most studied genera are Azospirillum, Bacillus and Pseudomonas of the fluorescent group that have shown benefits for the growth of several plant species. In this context, isolates of RPCP obtained from the rhizosphere of garlic maintained in protected cultivation were phenotypically and genotypically characterized and a growth promotion test in vivo was carried out, in protected cultivation. The biochemical tests used for phenotypic characterization were glucose and sucrose fermentation, Methyl Red (MR), catalase production and urea hydrolysis. The potential of plant growth induction was also evaluated by analyzing the production capacity of IAA (Indol-Acetic Acid) and calcium phosphate solubilization in vitro. Twenty-seven isolates were obtained. For the biochemical tests, 21 isolates were able to ferment glucose and 26, sucrose. For the other tests, all isolates showed a positive reaction. As for the mechanisms of plant growth promotion, 81.5% and 66.6% of the isolates presented IAA production and phosphate solubilizing capacity, respectively. The in vivo growth promotion test using maize (Zea mays) as a model indicated that the tested isolates (EB02, EB16, EB14, EB26, EB23) showed similarity to the treatment with 100% recommended nitrogen fertilization. The isolates were identified by sequencing the 16S rRNA gene. Fourteen isolates (51, 85% of the collection) were identified as Bacillus subtillis, including those tested in planta. These microorganisms present potential for the promotion of plant growth.Key words: growth promotion, rizobacteria, liliacea, corn.Resumo -O alho possui grande importância econômica e social em Santa Catarina. É um cultivo exigente em nutrientes, sendo necessária elevada quantidade de fertilizantes químicos, incrementando o custo de produção e o impacto ambiental. Uma alternativa ao uso de insumos são as Rizobactérias Promotoras de Crescimento de Plantas (RPCP). Dentre as RPCPs, os gêneros mais estudados são Azospirillum, Bacillus e Pseudomonas do grupo fluorescente que têm demonstrado benefícios para o crescimento de várias espécies vegetais. Neste contexto, foram caracterizados, fenotípica e genotipicamente, isolados de RPCP obtidos da rizosfera de alho mantido em cultivo protegido e realizado teste de promoção de crescimento in vivo, também em cultivo protegido. Os testes bioquímicos utilizados para caracterização fenotípica foram fermentação de glicose e sacarose, Vermelho de Metila (VM), produção de catalase e hidrólise da ureia. Também foi avaliado o potencial de indução do crescimento vegetal, mediante análise da capacidade de produção de AIA (Ácido Indol-Acético) e de solubilização de fosfatos de cálcio in vitro. Foram obtidos 27 isolados. Para ...

Isolates of Bacillus sp. from garlic: effect on corn development and plant growth-promoting mechanisms

“…The isolates EB02, EB12, EB14, EB16, and EB23 tested in the greenhouse showed a positive effect on plant growth, similar to the supplying 50 % of the required N (Leoncio and Botelho, 2017). These isolates were obtained from the medium without N supply, suggesting their BNF capacity.…”

“…The Bacillus isolates were obtained from the garlic soil rhizosphere brought from Dias farm in Curitibanos (SC) (Leoncio and Botelho, 2017). From a collection of 27 isolates, 14 were identified as belonging to the genus Bacillus by 16S RNA gene sequencing.…”

“…For this reason, ecological methods that maintain productivity are studied. One of the alternatives to reduce these costs is the use of Plant Growth Promoting Microorganisms (PGPM), such as nitrogen-fixing bacteria (Fukami et al, 2018), Plant Growth-Promoting Rhizobacteria (PGPR) (Leoncio and Botelho, 2017;Turatto et al, 2018,), and mycorrhizal fungi (Berbara et al, 2006). These microorganisms can play a relevant and strategic role to ensure high productivity at low cost, in addition to environmental benefits (Valadares-Inglis and Lopes, 2019).…”

“…Many plant-growth-promoting rhizospheric bacterial genera have been described, and Azospirillum, Pseudomonas, and Bacillus are the most studied (Ayyaz et al, 2016;Fukami et al, 2017;Botelho et al, 2019;Mpanga et al, 2019). The genus Bacillus is part of the main rhizobacteria group, which can induce plant development either directly (Lima et al, 2011;Leoncio and Botelho, 2017) or indirectly (Braga Júnior et al, 2017;Fira et al, 2018). These rhizobacteria influence germination, development, and yield of the crop due to several common mechanisms to PGPR (Kupper et al, 2003;Beneduzi et al, 2012;Khan et al, 2018;Turatto et al, 2018).…”

“…Twenty-seven Bacillus isolates was obtained from garlic rhizosphere samples grown in Nfb medium (Leoncio and Botelho, 2017). Five selected isolates showed potential for corn growth induction like N fertilization at a greenhouse experiment (Leoncio and Botelho, 2017). For this reason, this study aimed to evaluate the performance of these Bacillus sp.…”