Pereyra S A, Dill-Macky R
Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108.
Plant Dis. 2008 May;92(5):800-807. doi: 10.1094/PDIS-92-5-0800.
The presence of Fusarium spp. was examined in the residues of wheat, barley, corn, sunflower, pasture, and gramineous weed species common in wheat and barley cropping systems collected from no-tillage and reduced-tillage plots from February 2001 to March 2003 in Uruguay. Gibberella zeae was recovered from residues of wheat, barley, corn, sunflower, fescue, and the gramineous weeds Digitaria sanguinalis, Setaria spp., Lolium multiflorum, and Cynodon dactylon, except from birdsfoot trefoil or white clover. Of the Fusarium spp. obtained, G. zeae was the most frequently recovered from wheat and barley residues, while other species were more common in other crops. G. zeae declined over time in all residues examined. Wheat and barley residues produced more ascospores of G. zeae than corn or other gramineous residues. Sunflower residue did not support ascospore production, indicating that it probably did not contribute to primary inoculum. Wheat and barley residues supported G. zeae colonization longer in no-till than in reduced-tillage production systems and, thus, may represent major contributors to Fusarium head blight (FHB) inoculum in Uruguay. The presence of G. zeae in the gramineous components of pastures, weed species, and sunflower should be considered when implementing control strategies for FHB.
2001年2月至2003年3月期间，在乌拉圭免耕和少耕地块采集的小麦、大麦、玉米、向日葵、牧场以及小麦和大麦种植系统中常见的禾本科杂草的残体中，检测了镰刀菌属的存在情况。从除鸟趾三叶草或白三叶外的小麦、大麦、玉米、向日葵、羊茅以及禾本科杂草马唐、狗尾草属、多花黑麦草和狗牙根的残体中分离出了玉米赤霉。在所获得的镰刀菌属中，玉米赤霉最常从小麦和大麦残体中分离出来，而其他种类在其他作物中更为常见。在所有检测的残体中，玉米赤霉随时间减少。小麦和大麦残体产生的玉米赤霉子囊孢子比玉米或其他禾本科残体更多。向日葵残体不支持子囊孢子的产生，这表明它可能对初侵染接种体没有贡献。在免耕生产系统中，小麦和大麦残体比少耕生产系统更长时间地支持玉米赤霉的定殖，因此，可能是乌拉圭镰刀菌穗腐病（FHB）接种体的主要来源。在实施FHB控制策略时，应考虑牧场禾本科成分、杂草种类和向日葵中玉米赤霉的存在情况。
