Contrasting roles of abundant and rare root-associated fungi in wheat: Community assembly, heritability and agronomic impacts

Abstract

Root-associated fungal communities of wheat have a great impact on plant health, crop productivity and quality. However, little is known about the relationships among wheat varieties, fungal communities, and wheat productivity. In this study, we analyzed fungal communities in the endosphere and rhizosphere across 95 wheat varieties during two important wheat growth stages, i.e., the regreening stage and the heading stage. The results showed that abundant and core subcommunities played a prominent role in shaping the overall fungal community composition and structure. Stochastic processes including undominated process and dispersal limitation were the main assembly mechanisms in both endosphere and rhizosphere. Rhizosphere fungi at the regreening stage contained the most low-abundance keystone taxa, which contributed to maintaining community stability and functionality. Wheat quality and yield were positively affected by rare taxa in the rhizosphere at the regreening stage. Wheat yield showed significant positive correlations with keystone taxa and Glomeromycota at the heading stage. Abundant and core taxa exhibited higher heritability than rare and non-core taxa. In the rhizosphere, abundant subcommunity was enriched with taxa of low/moderate heritability at regreening stage, while rare subcommunity recruited taxa with higher heritability at heading stage. While abundant and core taxa strongly influenced overall community structure and composition, the importance of less abundant rhizosphere species should be emphasized for the keystone status, the relationships with wheat quality/yield, and the higher heritability. This study enhances our understanding of wheat-fungal interactions and their implications for sustainable agriculture, guiding wheat breeding and management practices to improve productivity.