Abstracts |
Knowledge about the presence and diversity of arbuscular mycorrhizal fungi (AMF)
in a specific area is an essential first step for utilizing these fungi in any application. The
community composition of AMF in intensively managed agricultural soil in the Sichuan Province of
southwest China currently is unknown. In one set of samples, AMF were trapped in pot cultures
from 40 fields growing legumes in the Panxi region, southeast Sichuan. In a second set of
samples, the MPN method with four-fold dilutions and maize as host was used to estimate infective
propagules in soil from another 50 agricultural sites throughout the province. Soil types were
heterogeneous and were classified as purple, yellow, paddy and red. Crops at each site were
either maize, wheat or sweet orange. From this set of soil, AMF spores were also extracted and
identified. Including all ninety soils, thirty glomeromycotan species in Glomus (20 species),
Acaulospora (four species), Scutellospora (three species), Ambispora (one species), Archaeospora
(one species) and Paraglomus (one species) were identified. Yellow, red and purple soils yielded
similar numbers of AMF species, while AMF species diversity was clearly lower in paddy soil. In
trap culture soils, the most frequent species were Glomus aggregatum or Glomus intraradices,
Glomus claroideum and Glomus etunicatum. The species Acaulospora capsicula, Acaulospora delicata,
G. Aggregatum (or intraradices), G. Claroideum, Glomus epigaeum, G. Etunicatum, Glomus luteum,
Glomus monosporum, Glomus mosseae and Glomus proliferum were successfully cultured as
single-species pot cultures in Plantago lanceolata. The three most frequent species in field
soils were G. Mosseae, Glomus caledonium and Glomus constrictum. MPN values varied between 17 and
3334 propagules 100 g soil(-1) among the fifty field sites sampled. Regression analysis,
including host&soil, log(P) and pH as explanatory variables explained 59% of the variation in
log(MPN). The highest MPN estimates were found in purple soil cropped with maize and citrus, 324
and 278 propagules 100 g soil(-1), respectively. The lowest MPN value, 54 propagules 100 g
soil(-1), was measured in wheat in purple and yellow soil. Despite intensive agricultural
management that can include often repeated tillage, our examination of 90 agricultural sites
revealed that soils of the Sichuan region have moderate to high numbers of infective AMF
propagules as well as a high AMF species diversity. This opens possibilities for further studies
and utilization of AMF in agriculture and horticulture in the Sichuan province, People's Republic
of China. |