PARENT SESSION
Poster Session # 10: Soil Ecology.

Tuesday, August 5 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Arbuscular mycorrhizal colonization and phosphorus acquisition of plants: Effects of coexisting plant species.

Chen, Xin^*,1, Zhi, Guiye¹, Hu, Shuijin², ¹ Zhejiang University, Hangzhou, Zhejiang, China² North Carolina State University, Raleigh, NC

ABSTRACT- Arbuscular mycorrhizal (AM) fungi influence interactions among plant species through enhancing nutrient uptake and possibly by facilitating nutrient transport among plants. However, the effects of one species on its coexisting species on AM infection and activity are not well understood. We examined root AM colonization and phosphorus (P) acquisition of plants in a highly P-limiting soil near Lanxi city, Zhejiang Province, China from the year 2000 to 2002. Three dominant native plant species, Kummerowia striata, Digitaria ciliaris and Ixeris denticulate, were planted at a rate 300 seedlings per plot (2m × 2m). In the monoculture, K. striata had the highest and D. ciliaris had the lowest AM infection, but plant P content was higher in I. denticulate and D. ciliaris than in K. striata. In the mixture, D. ciliaris and I. denticulate did not significantly affect the AM colonization or spore production, but increased the P content of the K. striata plants. K. striata and I. denticulate significantly increased root AM colonization of D. ciliaris roots, but had no impact on its P content. K. striata enhanced but D. ciliaris reduced AMF infection and P content of I. denticulate. These results suggest that the effects of one plant species on its coexisting species in mycorrhizal infection and P acquisition may be asymmetrical and cannot be predicted from the performance of individual species in monoculture.

Key words: plant species, mycorrhiza, phosphorus acquisition