Effects of single and mixed inoculation with two arbuscular mycorrhizal fungi in two different levels of phosphorus supply on β-carotene concentrations in sweet potato (Ipomoea batatas L.) tubers

• Published in: Plant and soil 2013-11, Vol.372 (1-2), p.361-374
• Main Authors: Tong, Yu, Gabriel-Neumann, Elke, Ngwene, Benard, Krumbein, Angelika, Baldermann, Susanne, Schreiner, Monika, George, Eckhard
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Beta carotene; Biological and medical sciences; Biomedical and Life Sciences; Diseases and pests; Ecology; Economic plant physiology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Glomus intraradices; Glomus mosseae; Health aspects; Host-parasite relationships; Ipomoea batatas; Life Sciences; Mycorrhizas; Nitrogen, phosphorus, potassium fertilizations; Phosphorus fertilization; Phosphorus in the body; Plant Physiology; Plant Sciences; Regular Article; Soil Science & Conservation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Solanum tuberosum; Sweet potatoes; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...)
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-013-1708-y

Aims This study aimed to determine the effect of arbuscular mycorrhizal (AM) fungi and phosphorus (P) supply levels on β-carotene concentrations in sweet potato ( Ipomoea batatas L.) tubers. Methods Two commercial AM fungal isolates of Glomus intraradices (IFP Glintra) and Glomus mosseae (IFP Glm) which differ in their life cycles were used. Sweet potato plants were grown in a horizontal split-root system that consisted of two root compartments. A root-free fungal compartment that allowed the quantification of mycelial development was inserted into each root compartment. The two root compartments were inoculated either with the same or with different AM isolates, or remained free of mycorrhizal propagules. Each fungal treatment was carried out in two P supply levels. Results In the low P supply level, mycorrhizal colonization significantly increased β-carotene concentrations in sweet potato tubers compared with the non-mycorrhizal plants. Glomus intraradices appeared to be more efficient in increasing β-carotene concentrations than G . mosseae . Dual inoculation of the root system with the two mycorrhizal fungi did not result in a higher increase in tuber β-carotene concentrations than inoculation with the single isolates. Improved P nutrition led to higher plant tuber biomass but was not associated with increased β-carotene concentrations. Conclusions The results indicate a remarkable potential of mycorrhizal fungi to improve β-carotene concentrations in sweet potato tubers in low P fertilized soils. These results also suggest that β-carotene metabolism in sweet potato tubers might be specifically activated by root mycorrhizal colonization.