Isolation and Molecular Characterization of Plant-Growth-Promoting Bacteria and Their Effect on Eggplant (Solanum melongena) Growth

Xuqing Li,Dingyi Li,Jingze Zhang,Yugen Jiang,Hong Wang,Ya Zhang,Bin Li,Temoor Ahmed,Jianli Yan

doi:10.3390/agriculture11121258

Xuqing Li, Dingyi Li + Show 7 more

Open Access

https://doi.org/10.3390/agriculture11121258

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Abstract

In recent years, the optimum development of land resources has become an important task for ensuring the security of food production in China. Soil microorganisms have been considered to play an important role in conferring soil fertility and productivity. In order to obtain the plant-growth-promoting bacteria in newly reclaimed land, a total of 988 bacterial strains were isolated from nine soil samples collected from different sites in wastelands in Hangzhou (Zhejiang Province, China), a rural mountainous area. Among them, five strains exhibited substantial potential of phosphate solubilization, nitrogen fixation, siderophore production and indole acetic acid production at both pH 5.0 and pH 7.0, and also promoted eggplant growth in immature soil from newly reclaimed land. Furthermore, bacterial strains ZJ62 and ZJ3-12 were identified as Pantoeadispersa and Pantoea ananatis, respectively, while strains ZJ5, ZJ9 and ZJ174 were identified as Burkholderiaarboris, Burkholderia pyrrocinia and Burkholderia pyrrocinia, respectively, based on colony morphology observation and phylogenetic analysis of 16S rDNA and the housekeeping genes sequences. Overall, the result of this study showed that the 5 obtained bacterial strains have a great potential in promoting plant growth in immature soil from newly reclaimed land.

Highlights

The limitation of available land resources and the gradual decrease of arable area with the expansion of urbanization have led to food supply challenges in China [1]
To meet the demand for land, we carried out a land reclamation of the benchland in the mountainous outskirts of the city of Hangzhou (Zhejiang Province, China), by raising the elevation of a waterbed and low-lying land using immature soils produced from road or reservoir construction
Soil bacteria that thrive in the rhizosphere, colonize plant roots and facilitate plant growth are designated as plant growth-promoting bacteria (PGPB) [6]

Summary

Introduction

The limitation of available land resources and the gradual decrease of arable area with the expansion of urbanization have led to food supply challenges in China [1]. The immature soils are those, which are new and not fully developed, characterized by slight weathering of the mineral material and generally containing a small amount of organic matter. These soils are not suitable for plant growth due to high gravel content, acidity and low nutrient contents [2]. Organic amendments, such as livestock manure, biosolids, wood residuals, and crop residues, have been widely used in soil reclamation owing to their ability to modify soils’ physical and chemical properties [3,4]. Soil bacteria that thrive in the rhizosphere, colonize plant roots and facilitate plant growth are designated as plant growth-promoting bacteria (PGPB) [6]

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Results