为了解致病性尖孢镰刀菌在土壤团聚体中分布状况并从土壤养分方面弄清其分布机制,本试验将土壤灭菌后接种致病性尖孢镰刀菌,并分别添加不同养分元素(有机物、氮、钾、钠、钙、镁、铜、锌、铁、锰)培养15 d后,通过干筛法将土壤筛分为4种粒径团聚体(>4.0 mm、2.1~4.0 mm、1.1~2.0 mm、≤1.0 mm),测定土体土及团聚体中尖孢镰刀菌数量.结果表明,添加有机物显著增加了土体土中尖孢镰刀菌数量,而添加氮、钙、镁、铜、锌、铁、锰显著降低了土体土中尖孢镰刀菌数量.添加不同养分元素显著改变了尖孢镰刀菌在不同粒径团聚体中的分布.通过相关性分析发现,土体土中尖孢镰刀菌数量与1.1~4.0 mm粒径团聚体中尖孢镰刀菌数量显著相关.据此推测,不同养分元素主要是通过影响尖孢镰刀菌在1.1~4.0 mm粒径团聚体中定殖状况而最终影响土体土中尖孢镰刀菌的生长.%To make clear the distribution of pathogenic Fusarium oxysporum in soil aggregates, the sterilized soil was inoculated with pathogenic F.oxysporum and applied with different nutrient elements (organic matter, N, K, Na, Ca, Mg, Cu, Zn, Fe, and Mn).After 15-d incubation, the soil was screened into four sizes of aggregates (>4.0 mm, 2.1-4.0 mm, 1.1-2.0 mm, ≤1.0 mm) and the populations of F.oxysporum in bulk soil and soil aggregates were measured.The results showed that the addition of organic matter significantly increased the number of F.oxysporum in bulk soil which was decreased by the addition of N, Ca, Mg, Cu, Zn, Fe, and Mn.The distribution of F.oxysporum in different sizes of aggregates was significantly changed by nutrient elements.The number of F.oxysporum in bulk soil was significantly correlated with that in the aggregates of 1.1-4.0 mm, indicating that nutrient elements influenced the growth of F.oxysporum in bulk soil by affecting its colonization in 1.1-4.0 mm aggregates.
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