Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2001
Publication Date: 4/1/2002
Citation: POULTON, J.L., BRYLA, D.R., KOIDE, R.T., STEPHENSON, A. MYCORRHIZAL INFECTION AND HIGH SOIL PHOSPHORUS IMPROVE VEGETATIVE GROWTH AND THE FEMALE AND MALE FUNCTIONS IN TOMATO.. NEW PHYTOLOGIST. 2002. Interpretive Summary: A glasshouse study was done to characterize the effect of arbuscular mycorrhizal fungi on plant reproduction. Mycorrhizal fungi occur in nearly all natural and agricultural soils, and commonly colonize roots of many plant species. Unlike root pathogens, these fungi can increase plant growth and reproduction by enhancing uptake of nutrients from soil, particularly phosphorus (P). Two cultivars of tomato were grown with or without the fungi in high or low P soil. Mycorrhizal infection and high P soil improved various reproductive traits in both cultivars including total flower production, fruit mass, seed number and pollen production per plant, and mean pollen production per flower. In one cultivar, mycorrhizal infection had a much greater effect on pollen production than on fruit and seed production. In general, mycorrhizal effects were largely the result of improved P acquisition.
Technical Abstract: To further characterize the effects of mycorrhizal infection and soil phosphorus (P) availability on plant fitness, this study examined their effects on the female and male functions, as well as vegetative growth of tomato (Lycopersicon esculentum). Two cultivars of tomato were grown in a glasshouse under three treatment combinations: nonmycorrhizal, low P (NMP0); nonmycorrhizal, high P (NMP3); and mycorrhizal, low P (MP0). Mycorrhizal infection and high soil P conditions improved several vegetative (leaf area, days until first flower and leaf P concentration) and reproductive traits (total flower production, fruit mass, seed number and pollen production per plant, and mean pollen production per flower). In general, mycorrhizal and P responses were greater for reproductive traits than vegetative traits. In one cultivar, these responses were greater for the male function than the female function. Thus, mycorrhizal infection and high soil P conditions enhanced fitness through both the female and male functions. Similar trends were usually observed in the NMP3 and MP0 treatments, suggesting that mycorrhizal effects were largely the result of improved P acquisition.