TY - JOUR
T1 - Defoliation effects on the community structure of arbuscular mycorrhizal fungi based on 18S rDNA sequences
AU - Saito, Katsuharu
AU - Suyama, Yoshihisa
AU - Sato, Shusuke
AU - Sugawara, Kazuo
N1 - Funding Information:
Acknowledgements We thank M. Saito, National Institute for Agro-Environmental Sciences (NIAES) for valuable suggestions. We are grateful to the members of the Laboratory of Land Ecology, in particular to Y. Yashima, for their assistance in grassland management. We appreciate discussions with A. Nishiwaki of Miyazaki University and N. Watanabe of National Agricultural Research Center for Hokkaido Region (NARCH) about Japanese native grasslands and ecology of the wild plants. This research was partially supported by the Ministry of Education, Culture, Sports, Science and Technology, Grant-in-Aids for Scientific Research (B) (2), 14360157, 2002.
PY - 2004/12
Y1 - 2004/12
N2 - The effects of defoliation on arbuscular mycorrhizal (AM) associations in the field were investigated in terms of the community structure of AM fungi colonizing roots of grassland plants; the carbohydrate balance of the host plants was also determined. We focused on two plant species dominating Japanese native grasslands: the grazing-intolerant species Miscanthus sinensis and the grazing-tolerant species Zoysia japonica. Community structures of AM fungi were determined from 18S rRNA gene sequences. The dominant fungal group in both plant species was the Glomus clade, which was classified into several phylogenetic groups based on genetic distances and topology. In Miscanthus roots, the Glomus-Ab, Glomus-Ac, and Glomus-Ad groups were detected almost equally. In Zoysia roots, the Glomus-Ab group was dominant. Defoliation effects on the community structure of AM fungi differed between the plant species. In Miscanthus roots, the percentage of root length colonized (%RLC) by the Glomus-Ac and Glomus-Ad groups was significantly reduced by defoliation treatment. On the other hand, AM fungal group composition in Zoysia roots was unaffected by defoliation except on the last sampling date. Decreased %RLC by Glomus-Ac and Glomus-Ad coincided with decreased non-structural carbohydrate (NSC) levels in host plants; also, significant positive correlations were found between the %RLC and some NSC levels. On the other hand, the %RLC by Glomus-Ab in both plant species was unaffected by the NSC level. These results suggest that AM fungal groups have different carbohydrate requirements from host plants.
AB - The effects of defoliation on arbuscular mycorrhizal (AM) associations in the field were investigated in terms of the community structure of AM fungi colonizing roots of grassland plants; the carbohydrate balance of the host plants was also determined. We focused on two plant species dominating Japanese native grasslands: the grazing-intolerant species Miscanthus sinensis and the grazing-tolerant species Zoysia japonica. Community structures of AM fungi were determined from 18S rRNA gene sequences. The dominant fungal group in both plant species was the Glomus clade, which was classified into several phylogenetic groups based on genetic distances and topology. In Miscanthus roots, the Glomus-Ab, Glomus-Ac, and Glomus-Ad groups were detected almost equally. In Zoysia roots, the Glomus-Ab group was dominant. Defoliation effects on the community structure of AM fungi differed between the plant species. In Miscanthus roots, the percentage of root length colonized (%RLC) by the Glomus-Ac and Glomus-Ad groups was significantly reduced by defoliation treatment. On the other hand, AM fungal group composition in Zoysia roots was unaffected by defoliation except on the last sampling date. Decreased %RLC by Glomus-Ac and Glomus-Ad coincided with decreased non-structural carbohydrate (NSC) levels in host plants; also, significant positive correlations were found between the %RLC and some NSC levels. On the other hand, the %RLC by Glomus-Ab in both plant species was unaffected by the NSC level. These results suggest that AM fungal groups have different carbohydrate requirements from host plants.
UR - http://www.scopus.com/inward/record.url?scp=11844262750&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=11844262750&partnerID=8YFLogxK
U2 - 10.1007/s00572-003-0286-x
DO - 10.1007/s00572-003-0286-x
M3 - Article
C2 - 14727168
AN - SCOPUS:11844262750
VL - 14
SP - 363
EP - 373
JO - Mycorrhiza
JF - Mycorrhiza
SN - 0940-6360
IS - 6
ER -