Methods of screening for microorganisms that impart beneficial properties to plants

A method for the selection of one or more microorganisms capable of improving resistance or tolerance of one or more plants to an abiotic stressor, the method comprising the steps of:

• a) subjecting one or more plants to a growth medium in the presence of a first set of one or more microorganisms, wherein the growth medium comprises the abiotic stressor;
• b) selecting one or more plant parts from the one or more plants of step a), wherein the selection is based on increased resistance or tolerance of the one or more plants to the abiotic stressor;
• c) acquiring a second set of one or more microorganisms from said one or more plant parts selected in step b);
• and
• d) repeating steps a) to c) one or more times, wherein the second set of one or more microorganisms acquired in step c) is used as the first set of microorganisms in step a) of any successive repeat.