长期定位施肥对石灰性紫色水稻土AMF多样性的影响

Effects of long-term fertilization on arbuscular mycorrhizal fungi community in calcareous purple paddy soil

为了解长期定位施肥对石灰性紫色水稻土丛枝菌根真菌(AMF)物种多样性的影响,从稻麦轮作下连续26年定位施农家肥(M)、氮肥+农家肥(NM)、氮磷肥+农家肥(NPM)、氮磷钾肥+农家肥(NPKM)、不施肥(CK)、氮肥(N)、氮磷肥(NP)、氮磷钾肥(NPK)等不同施肥处理小区采集根区土样,分离鉴定AMF、测定多样性特征。共鉴定出17种AMF,其中球囊霉属Glomus12种,占已分离总数的70.5%,为优势属;无梗囊霉属Acaulospora3种,占17.6%;原囊霉属Archaeospora和内养囊霉属Entrophospora各1种,各占5.9%。无论是石灰性紫色土种植水稻还是小麦,AMF侵染率最高的施肥处理均为无肥处理(CK),施肥特别是磷肥,降低AMF侵染率、孢子密度、相对多度和种丰度。变性梯度凝胶电泳(denaturinggradient gel electrophoresis,DGGE)分析结果表明,不施肥对照(CK)的AMF多样性最丰富,多样性指数最高,水稻和小麦种植下的多样性指数分别为2.68和3.02;与无机肥处理相比,农家肥配施无机肥提高了AMF多样性指数。农家肥配施无机肥更有利于AMF发育。

To determine the influence of long term fertilization on arbuscular mycorrhizal fungi （AMF） species diversity in calcareous purplish paddy soil, rhizosphere soil samples collected from different designed plots continuously supplied with manure only （M）, nitrogen fertilizer plus manure （NM）, nitrogen and phosphoric fertilizer plus manure （NPM）, nitrogen, phosphoric and potassium fertilizer plus manure （NPKM）, mineral nitrogen （N）, nitrogen-phosphoric fertilizer （NP）, nitrogen and phosphoric and potassium fertilizer （NPK） and without treatment （CK）, under rice-wheat rotations for 26 years were mycologically investigated. The results showed that there are 17 species of AMF, among them, 12 species belong to Glomus, accounting for 70.5 percent of the total isolated species. Three species belong to Acaulospora, accounting for 17.6 percent of the isolated species. One species belongs to Archaeospora and one species Entrophospora, accounting for 5.9 percent of isolated species. Regardless of wheat and rice, the AMF highest infection rate emerged in the control treatment （CK）. Fertilizer treatments especially using phosphorus would decrease the infection rate, spore density, relative abundance and species richness of AMF. Denaturing gradient gel electrophoresis （DGGE） profiles showed that both the AMF community structure and Shannon diversity index were the highest in the soil under CK as compared with those in the soil under any other fertilizer treatments. AMF diversity index in planting plots of wheat and rice were 2.68 and 3.02, respectively. In compared with the inorganic fertilizer treatments, the combining use of manure and inorganic fertilizer increased the AMF diversity index. The results suggested that the mixing of manure and inorganic fertilizer would be more beneficial to the development of the soil AMF.