Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : The rhizobiome of barley species : comparison of traditional and modern varieties

Auteur : Lanbach, Daniel

Université de soutenance : Universität Innsbruck

Grade  : Master of Science (MS) 2022

Résumé partiel
Due to the progress of climate change, crops are increasingly facing new challenges. The spread of phytopathogens, competing neophytes and the increase in droughts or extreme precipitation events are just a few of the many consequences of global warming. In addition, the need to produce food sustainably and organically is increasing, which cannot be satisfied by traditional agrochemical-based agriculture.

To meet these challenges in the future, research on the interactions between plants and the microorganisms living in the soil has become a focus of scientific attention. The area of the soil influenced by roots, the rhizosphere, is a highly specific habitat for a wide variety of microorganisms. The exchange of nutrients takes place through targeted communication between plants and microorganisms. Microorganisms benefit from the carbohydrates released by the plants and in return provide access to complex substrates. In addition, the microorganisms in the rhizosphere cause the plants to develop different characteristics, which can manifest themselves in the form of increased resistance to pests or tolerance to unfavourable environmental conditions, among other things.

The present work deals with the characterisation of the microbial community within the rhizosphere of barley (Hordeum sp.). Barley is not only one of the oldest, but still one of the most important globally cultivated crops.

Four different barley cultivars are studied, two of them can be assigned to two traditional landraces and two to modern cultivars. Each group contains one barley variety with a preference for either "moist" or "dry" cultivation conditions.

The aim of the present investigation was to characterise the rhizobiome of barley, to compare it with the microbiome of the surrounding bulk soil and to detect specific marker organisms for barley varieties, their cultivar type (traditional vs modern) and water preferences in order to contribute to the understanding of the complex interactions between plants and microorganisms and ultimately sustainable agriculture in times of changing environmental conditions.

Between the investigated fractions, rhizosphere vs. bulk soil, a highly significant difference in alpha- and betadiversity could be detected. The species richness in the rhizosphere was significantly lower than in the bulk soil, but varied strongly between barley varieties, suggesting the emergence of a different microbial community and indicating a barley variety specific influence. The cultivar specific composition of the microbial community was observed from the phylum to the genus level.

Présentation

Version intégrale (2,8 Mb)