Synergistic Effects of Plant Growth Promoting Rhizobacteria and Chitosan on In Vitro Seeds Germination, Greenhouse Growth, and Nutrient Uptake of Maize (Zea mays L.).

Lamine Baba-Moussa,Nadège A Agbodjato,Adolphe Adjanohoun,Léonce Agbessi,Pacôme A Noumavo

doi:10.1155/2016/7830182

Abstract

This study aimed to assess the effects of three plant growth promoting rhizobacteria (PGPR) and chitosan either singly or in combination on maize seeds germination and growth and nutrient uptake. Maize seeds were treated with chitosan and bacterial solution. The germination and growth tests were carried out in square Petri dishes and plastic pots. The combination chitosan-A. lipoferum-P. fluorescens has increased the seeds vigor index up to 36.44% compared to the control. In comparison to the control, P. putida has significantly improved root weight (44.84%) and germinated seed weight (31.39%) whereas chitosan-P. putida has increased the shoot weight (65.67%). For the growth test, the maximal heights (17.66%) were obtained by plants treated with the combination A. lipoferum-P. fluorescens-P. putida. Chitosan-P. fluorescens induced the highest increases of leaves per plant (50.09%), aerial (84.66%), and underground biomass (108.77%) production. The plants inoculated with A. lipoferum had the large leaf areas with an increase of 54.08%, while combinations P. fluorescens-P. putida and chitosan-A. lipoferum improved the aerial and underground dry matter of plants to 26.35% and 18.18%. The nitrogen content of the plants was increased by chitosan-A. lipoferum-P. fluorescens-P. putida with an increasing of 41.61%. The combination of chitosan and PGPR can be used as biological fertilizers to increase maize production.

Highlights

Nowadays, the use of synthesis products such as mineral fertilizers, pesticides, and growth regulators in agriculture causes a real public health problem
plant growth promoting rhizobacteria (PGPR) are soil bacteria capable of colonizing the root systems of many cultures and impact positively the plant physiological process [2]. These bacteria are involved in the plant resistance to biotic and/or abiotic stresses [3]. Though their mechanisms of action are not fully elucidated, PGPR are currently classified into four groups: (i) “biofertilizers” for their ability to solubilize mineral phosphates and to fix atmospheric nitrogen [4], (ii) “phytostimulators” for their ability to produce plant hormones [5], (iii) “rhizoremediators” for their capacity to degrade organic pollutants [6], and at last (iv) “biopesticides” for their ability to produce
The present study aims to assess the effect of three PGPR (A. lipoferum, P. fluorescens, and P. putida) and chitosan either singly or in combination on in vitro seeds germination and greenhouse growth of maize

Summary

Introduction

The use of synthesis products such as mineral fertilizers, pesticides, and growth regulators in agriculture causes a real public health problem. It is urgent to find alternative agricultural practices that do not use the agrochemical products or significantly limit their use. In this perspective, the use of bioresources such as plant growth promoting rhizobacteria (PGPR) and chitosan (chitin derived) caught the researchers attention, because they have considerable agronomic advantages. PGPR are soil bacteria capable of colonizing the root systems of many cultures and impact positively the plant physiological process [2]. These bacteria are involved in the plant resistance to biotic and/or abiotic stresses [3]. Though their mechanisms of action are not fully elucidated, PGPR are currently classified into four groups: (i) “biofertilizers” for their ability to solubilize mineral phosphates and to fix atmospheric nitrogen [4], (ii) “phytostimulators” for their ability to produce plant hormones [5], (iii) “rhizoremediators” for their capacity to degrade organic pollutants [6], and at last (iv) “biopesticides” for their ability to produce

Objectives

Methods

Results

Conclusion