Root development in agronomically distinct six‐rowed barley (Hordeum vulgare) cultivars inoculated with Azospirillum brasilense Sp7

Abstract

AbstractThe growth‐promoting rhizobacteria Azospirillum brasilense Sp7 positively affects many crops, but its influence on barley remains to be fully investigated. The aim of this study was to track early root growth of four barley cultivars that are widely used in Spanish breeding programmes under different growing scenarios. Different growth conditions are hypothesized to affect the response of young plants to A. brasilense Sp7, so seeds were inoculated with A. brasilense Sp7 and directly sown in the growth chamber, or planted in vitro. Plant height was measured and root structure analysed with the WinRHIZO program. Azospirillum brasilense Sp7 inoculation increased the length, surface area and number of root tips in both systems and in most cultivars in a similar way. Cultivars ‘Barberousse’ and ‘Plaisant’ were the most responsive to A. brasilense Sp7 treatment, while ‘Albacete’ was especially interesting in terms of its physiological interaction with A. brasilense Sp7 under abiotic stress imposed by the in vitro system. The utility of the in vitro system is criticized.