INOCULATION AND ISOLATION OF PLANT GROWTH-PROMOTING BACTERIA IN MAIZE GROWN IN VITÓRIA DA CONQUISTA, BAHIA, BRAZIL

Joelma Da Silva Santos,Vera Lúcia Divan Baldani,Cristina Meira De Jesus,Joilson Silva Ferreira,Tarciana De Oliveira Viana

doi:10.1590/01000683rbcs20150725

Abstract

Maize is among the most important crops in the world. This plant species can be colonized by diazotrophic bacteria able to convert atmospheric N into ammonium under natural conditions. This study aimed to investigate the effect of inoculation of the diazotrophic bacterium Herbaspirillum seropedicae (ZAE94) and isolate new strains of plant growth-promoting bacteria in maize grown in Vitória da Conquista, Bahia, Brazil. The study was conducted in a greenhouse at the Experimental Area of the Universidade Estadual do Sudoeste da Bahia. Inoculation was performed with peat substrate, with and without inoculation containing strain ZAE94 of H. seropedicae and four rates of N, in the form of ammonium sulfate (0, 60, 100, and 140 kg ha-1 N). After 45 days, plant height, dry matter accumulation in shoots, percentage of N, and total N (NTotal) were evaluated. The bacteria were isolated from root and shoot fragments of the absolute control; the technique of the most probable number and identification of bacteria were used. The new isolates were physiologically characterized for production of indole acetic acid (IAA) and nitrogenase activity. We obtained 30 isolates from maize plants. Inoculation with strain ZAE94 promoted an increase of 14.3 % in shoot dry mass and of 44.3 % in NTotal when associated with the rate 60 kg ha-1 N. The strains N11 and N13 performed best with regard to IAA production and J06, J08, J10, and N15 stood out in acetylene reduction activity, demonstrating potential for inoculation of maize.

Highlights

Maize (Zea mays L.) is among the most important crops in the world
This study aimed to investigate the effect of inoculation of the diazotrophic bacterium Herbaspirillum seropedicae (ZAE94) and isolate new strains of plant growth-promoting bacteria in maize grown in Vitória da Conquista, Bahia, Brazil
This article aimed to investigate the effect of inoculation of the diazotrophic bacterium H. seropedicae (ZAE94) and isolate new strains of plant growth-promoting bacteria in maize grown in Vitória da Conquista, Bahia, Brazil

Summary

Introduction

Maize (Zea mays L.) is among the most important crops in the world. In Brazil, this grain is significant both in the economic and the social fields, being used as food and feed, aside from serving as raw material in a diverse food processing procedures.Of the whole national maize production, about 70 to 80 % of the grain yield is used in the feed industry (Kwiatkowski and Clemente, 2009). Maize (Zea mays L.) is among the most important crops in the world. In Brazil, this grain is significant both in the economic and the social fields, being used as food and feed, aside from serving as raw material in a diverse food processing procedures. Of the whole national maize production, about 70 to 80 % of the grain yield is used in the feed industry (Kwiatkowski and Clemente, 2009). Nitrogen availability is a limiting factor in agricultural productivity. It is one of the nutrients absorbed in greater quantity by crops. In maize, it influences the grain yield directly (Amado et al, 2002)

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