Rhizobial diversity associated with the spontaneous legume Genista saharae in the northeastern Algerian Sahara

• Published in: Symbiosis (Philadelphia, Pa.) Vol. 71; no. 2; pp. 111 - 120
• Main Authors: Chaïch, Khaled, Bekki, Abdelkader, Bouras, Noureddine, Holtz, Michael D., Soussou, Souhir, Mauré, Lucette, Brunel, Brigitte, de Lajudie, Philippe, Cleyet-Marel, Jean-Claude
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-02-2017; Springer Nature B.V; Springer Verlag
• Subjects: Biodiversity and Ecology; Biomedical and Life Sciences; Desertification; Developmental Biology; Drought resistance; Ecology; Environmental Sciences; Evolutionary Biology; Genetic diversity; Legumes; Life Sciences; Microbiology; Phylogeny; Plant Sciences; Preservation; RecA protein; Root nodules; rRNA 16S; Sodium chloride; Species; Strains (organisms); Rhizobial diversity; Housekeeping genes; fixation; Spontaneous legume; Algerian Sahara; N; préservation de l'environnement; diversité génétique; stabilisation du sol; dune; desertization; phylogénétique; soil; sol; sahara; désertification; rhizobial diversity; legume; genista saharae; N-2-fixation; soil stabilization; genêtic variation; housekeeping genes; caractérisation génétique; fixation de l'azote; légumineuse; spontaneous legume; algérie
• ISSN: 0334-5114; 1878-7665
• DOI: 10.1007/s13199-016-0414-y

Genista saharae
is an indigenous shrub legume that spontaneously grows in the northeastern Algerian Sahara. It is known for efficient dune fixation and soil preservation against desertification, due to its drought tolerance and its contribution to sustainable nitrogen resources implemented by biological N
2
-fixation. In this study, the root nodule bacteria of
G. saharae
were investigated using phenotypic and phylogenetic characterization. A total of 57 rhizobial strains were isolated from nodules from several sites in the hyper-arid region of Metlili and Taibet (east Septentrional Sahara). They all nodulate
G. saharae
species but they differed in their symbiotic efficiency and effectiveness. The genetic diversity was assessed by sequencing three housekeeping genes (
atpD
,
recA
and 16S rRNA). The majority of isolates (81 %) belonged to the genus
Ensifer
(previously
Sinorhizobium
), represented mainly by the species
Ensifer meliloti
. The next most abundant genera were
Neorhizobium
(17 %) with 3 different species:
N. alkalisoli
,
N. galegae
and
N. huautlense
and
Mesorhizobium
(1.75 %) represented by the species
M. camelthorni
. Most of the isolated strains tolerated up to 4 % (w/v) NaCl and grew at 45 °C. This study is the first report on the characterization of
G. saharae
microsymbionts in the Algerian Sahara.