Mutualism breakdown in breadfruit domestication

• Published in: Proceedings of the Royal Society. B, Biological sciences Vol. 279; no. 1731; pp. 1122 - 1130
• Main Authors: Xing, Xiaoke, Koch, Alexander M, Jones, A. Maxwell P, Ragone, Diane, Murch, Susan, Hart, Miranda M
• Format: Journal Article
• Language: English
• Published: England Royal Society 22.03.2012; The Royal Society
• Subjects: Artocarpus; Artocarpus - microbiology; Breadfruit; crops; Crops, Agricultural - microbiology; cultivars; Domestication; Food crops; food security; Fruits; Fungi; islands; Melanesia; mutualism; Mycorrhiza; Mycorrhizae - physiology; Mycorrhizal fungi; Mycorrhizas; Plant domestication; Plant roots; Plant Roots - microbiology; Plants; Polymerase chain reaction; Polynesia; roots; species diversity; stress tolerance; symbionts; Symbiosis; vesicular arbuscular mycorrhizae; Polynesia; Melanesia
• ISSN: 0962-8452; 1471-2954
• DOI: 10.1098/rspb.2011.1550

During the process of plant domestication, below-ground communities are rarely considered. Some studies have attempted to understand the changes in root symbionts owing to domestication, but little is known about how it influences mycorrhizal response in domesticated crops. We hypothesized that selection for above-ground traits may also result in decreased mycorrhizal abundance in roots. Breadfruit (Artocarpus sp.) has a long domestication history, with a strong geographical movement of cultivars from west to east across the Melanesian and Polynesian islands. Our results clearly show a decrease in arbuscular mycorrhizas (AMs) along a domestication gradient from wild to recently derived cultivars. We showed that the vesicular and arbuscular colonization rate decreased significantly in more recently derived breadfruit cultivars. In addition, molecular analyses of breadfruit roots indicated that AM fungal species richness also responded along the domestication gradient. These results suggest that human-driven selection for plant cultivars can have unintended effects on below-ground mutualists, with potential impacts on the stress tolerance of crops and long-term food security.