Root-associated bacteria promote grapevine growth: from the laboratory to the field

Abstract

Background and Aims Laboratory and greenhouse experiments have shown that root-associated bacteria have beneficial effects on grapevine growth; however, these effects have not been tested in the field. Here, we aimed to demonstrate whether bacteria of different geographical origins derived from different crop plants can colonize grapevine to gain a beneficial outcome for the plant leading to promote growth at the field scale. Methods To link the ecological functions of bacteria to the promotion of plant growth, we sorted fifteen bacterial strains from a larger isolate collection to study in vitro Plant Growth Promoting (PGP) traits. We analysed the ability of these strains to colonise the root tissues of grapevine and Arabidopsis using greenfluorescent-protein-labelled strain derivatives and a cultivation independent approach. We assessed the ability of two subsets randomly chosen from the 15 selected strains to promote grapevine growth in two field-scale experiments in north and central Italy over two years. Parameters of plant vigour were measured during the vegetative season in de novo grafted vine cuttings and adult productive plants inoculated with the bacterial strains. Results Beneficial bacteria rapidly and intimately colonized the rhizoplane and the root system of grapevine. In the field, plants inoculated with bacteria isolated from grapevine roots out-performed untreated plants. In both the tested vineyards, bacteria-promotion effects largely rely in the formation of an extended epigeal system endowed of longer shoots with larger diameters and more nodes than non-inoculated plants.Conclusions PGP bacteria isolated in the laboratory can be successfully used to promote growth of grapevines in the field. The resulting larger canopy potentially increased the photosynthetic surface of the grapevine, promoting growth.

Root bacterial endophytes confer drought resistance and enhance expression and activity of a vacuolar H+‐pumping pyrophosphatase in pepper plants

“…Drought is one of the most severe abiotic plant stresses that strongly limits crop productivity (Calanca, 2017). Plants have evolved mechanisms both to cope with drought independently, including escape strategies, avoidance and tolerance (Jarzyniak and Jasi nski, 2014), and to cooperate with beneficial plant growth promoting (PGP) microorganisms that provide the plant-host with ecosystem services and activities that mitigate the effects of several abiotic stresses (Lau and Lennon, 2011;Marasco et al, 2013a,b;Chen et al, 2017;Rolli et al, 2017;Vergani et al, 2017).…”

Growth, Yield and Chemical Composition Response of some Legume Crops to Inoculation with Non-rhizobial Endophytic Bacteria from Melilotus indicus (L.) All. Nodules

“…All the tested endophytic non-rhizobial strains improve the growth and increased yield of the four legume plants. This means that endophytes bacteria are appropriate for inoculation, indicating the ability of the inoculated bacteria to colonize plant and to perform the beneficial effect (Souza et al, 2015;Rolli et al, 2017). We found that bacterial strains consistently increased one or more of plant growth parameter.…”

Vine Growth and Yield Response of Alphonse Lavallée (V. Vinifera L.) Grapevines to Plant Growth Promoting Rhizobacteria Under Alkaline Condition in Soilless Culture

“…Generally, fertilization management is relevant to the application of suitable amount of non-chemical and chemical fertilizers, which result in an increase of soil quality, plant nutrition, cultural advantages, and finally, obtaining of suitable yield [Shakeri et al 2016]. For non-chemical sustainable fertilization strategies, manipulation of symbiotic and free-living plantgrowth-promoting rhizobacteria (PGPR) has become a significant component in many intensive cropping systems [Bashan et al 2004, Rolli et al 2017.…”