Screening of rhizosphere bacteria from grapevine for their suppressive effect on Xiphinema index Thorne & Allen on in vitro grape plants

Abstract

Xiphinema index is the most aggressive root parasite affecting vines in Chile, controlled mainly chemically. The aim of this study was to identify rhizobacteria in grapevine roots growing in infested soils and to determine if some of these affect the parasitism caused by the nematode. Rhizobacteria of ungrafted grapevine cultivars from 11 vineyards were isolated using TSBA and identified with FAMEs analysis. The antagonistic effect to X. index of those from soils 1 to 4 was assessed in 500 ml pots treating 2 months old in vitro plants with a bacterial suspension containing 1×10 6 c.f.u./ml and 400 nematodes, determining after 4 months growth nematode populations and root damages. Also culture filtrates were assessed. 400 isolates in 25 genera were obtained from the 11 vineyards. The most frequent species were Pseudomonas putida (35.1%), Escherichia coli (7.6%) and Pseudomonas fluorescens (6.1%). Isolates of soils 1 to 4, show that Bacillus megaterium, B. brevis, Pseudomonas corrugata, P. savastanoi, Stenotrophomonas maltophilia and Serratia plymuthica reduced root damage and suppressed populations, meanwhile strains of B. brevis and Comamonas acidovorans increased plant growth but did not control nematodes. It is concluded that these isolates may be useful in biological control programmes in vineyards.

Metagenomic analysis exploring taxonomic and functional diversity of soil microbial communities in Chilean vineyards and surrounding native forests

“…Although Mediterranean Chile is one of the most important wine-producing regions and the area occupied by vineyards in Chile has rapidly expanded (Viers et al, 2013), there are very few studies exploring the microbial diversity of these vineyard soils (but see Aballay, Maternsson & Persson, 2011; Castañeda et al, 2015). Recently, Castañeda et al (2015) have shown that the soil bacterial communities in native forests and vineyards are similar, whereas the fungal communities differ between the habitats.…”

Plant Growth Promotion Potential Is Equally Represented in Diverse Grapevine Root-Associated Bacterial Communities from Different Biopedoclimatic Environments

“…Historically, grape and derived products held an important economic role in the area, and this importance persists to the present day. Vineyards are extremely sensitive to phytopathogen attacks, and a huge interest has been devoted to understanding the mechanisms of virulence [1] and environmental-friendly biocontrol approaches [2]. Certain biocontrol strategies rely on the exploitation of beneficial traits of plant growth-promoting (PGP) microorganisms that are naturally associated with plants [3].…”

Exoenzymes and metabolites related to the nematicidal effect of rhizobacteria on Xiphinema index Thorne & Allen

“…The results obtained in this study indicate that rhizobacterial filtrates are able to produce in vitro mortality on X. index adults and juveniles and are in agreement with previous works (Aballay et al . ). Additionally, the results of the present work agree with other studies on intensively studied species, such as M. incognita (Jonathan et al .…”