Crops and their wild progenitors recruit beneficial and detrimental soil biota in opposing ways

Abstract

Conventional agriculture promotes negative feedbacks of soil microbes on crop performance (plant soil feedbacks, PSFs) by stimulating species-specific pathogens. Crop traits, modified by domestication, also influence PSFs. Therefore, we asked if crop cultivars and their wild progenitors promote soil pathogens and mutualists differently, and thus trigger different PSFs. We studied PSFs in cultivated varieties and wild progenitors of ten crops. In a first season, we grew all genotypes separately in a common soil to obtain genotype-specific soil inocula (‘trained soil’) for a second season. In season two, we examined the effects of the trained soil on plant interactions with arbuscular mycorrhizal fungi and with root-feeding nematodes, and on plant performance. Mycorrhizal colonization was lower, and nematode infection rate was higher, in plant roots growing on soils previously trained by domesticated plants. Moreover, domesticated plants showed lower mycorrhizal colonization, and higher nematode infection rates than their wild progenitors, irrespective of previous soil training. The response of plant performance to soil training was species-specific and unrelated to cultivated vs wild status. Soil legacies differed between cultivated varieties and their wild progenitors, suggesting an impact of domestication on the way rhizosphere organisms are recruited, on the resistance of plants to herbivores, and on their interactions with root mutualists.