长期定位施肥土壤中AM真菌对寄主植物的侵染状况

Colonization status of arbuscular mycorrhizal fungi on host plants grown in long-term fixed fertilization field

分别于2003年9月和2004年5月在莱阳农学院长期(26年)定位施肥试验田采集玉米和小麦根系,以测定不同施肥处理对丛枝菌根(AM)真菌侵染状况的影响。结果表明长期定位施氮(N)肥显著降低了AM真菌对寄主植物的侵染率(MCP)、丛枝着生率(ACP)、单位根长泡囊数(NV)和侵入点数(NE)。高N处理的小麦MCP低于低N处理,高N处理的玉米ACP低于低N处理。长期定位施有机肥,尤其是高有机肥处理显著降低了MCP、ACP和NE。有机肥和N肥配施也降低了MCP、ACP、NV和NE,以高有机肥和高N肥配施处理的降低效应最大。除小麦根系NV外,长期定位NPK配合施用降低了玉米和小麦的MCP、ACP、NV和NE。其中,以NP处理的玉米ACP、小麦的MCP和ACP最低。另外,低有机肥与N肥配施和NPK配施处理条件下玉米MCP高于小麦。结论认为不同施肥体制对作物菌根生长发育及其结构具有不同影响,而且有机肥和N肥在影响AM真菌侵染方面存在互作。

Roots of corn （Zea mays L.） and wheat （Triticum aestivm L.） grown in a long-term fixed fertilization field of Laiyang Agricultural College were collected in September 2003 and May 2004, respectively. The mycorrhizal colonization status of the root in different treatments was determined. Results showed that the long-term nitrogen （N） fertilization treatment significantly reduced mycorrhizal colonization percentage （MCP）, arbuscule colonization percentage （ACP）, number of vesicle （NV） and entry points （NE） per mm root length. The MCP of wheat treated with low N was higher than that treated with high N, while ACP of corn treated with high N was lower than that treated with low N. The MCP, ACP, NV, and NE of the plants treated with long-term fixed manure fertilization, especially high manure fertilization were significantly reduced. Manure mixed with N fertilizer also significantly reduced MCP, ACP, NV, and NE. Except NV of wheat, the long-term fixed NPK fertilization decreased MCP, ACP, NV, and NE on corn and wheat roots. In NP treatment, the ACP on corn and MCP and ACP on wheat showed the lowest. In addition, the MCP of corn treated with low manure mixed with N fertilization, and NPK was higher than that of wheat. It is concluded that the development of mycorrhizas and their structures were influenced with different fertilization regimes. There are interactions between manure and nitrogen fertilization in influencing AM fungal colonization.