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Effect Of Mycorrhizal Colonization And Light Limitation On Growth And Reproduction Of Lima Bean (Phaseolus Lunatus L.), Daniel J. Ballhorn, Jess A. Millar

Biology Faculty Publications and Presentations

Plants can respond with sink stimulation of photosynthesis when colonized with fungal or bacterial root symbionts, compensating costs of carbohydrate allocation to the microbes. However, constraints may arise under light limitation when plants cannot extensively increase photosynthesis. We hypothesize that under such conditions the costs for maintaining the symbiosis outweigh the benefits, ultimately turning the mutualist microbes into parasites, resulting in reduced plant growth and reproduction.

Using lima bean (Phaseolus lunatus) as experimental plant, we applied two levels of light (full light, 75% shading) and microbial inoculation (sterile soil, mycorrhizal fungi) and quantified both vegetative and generative plant …