Huelva (Spain) is the largest European producer of blueberry for early spring harvest. Blueberry fields in Huelva are intensively cultured. Canker or stem blight of blueberry and the resultant twig dieback caused mostly by botryosphaeriaceous species has become a serious problem throughout blueberry producing areas worldwide; although the presence of Botryosphaeriaceae species associated with this disease varies. In Huelva, blueberry canker or stem blight has been attributed to Neofusicoccum parvum, N. australe and Lasiodiplodia theobromae. Meanwhile, Macrophomina phaseolina has been associated with blueberry charcoal rot. Plants with cankers and root rot, due to Botryosphaeriaceae species and M. phaseolina respectively, were found frequently. This observation has led to consider the possible interaction of these infections. Thus, blueberry plants from a farm with high canker incidence and severity were sampled, and stems and roots of diseased plants were analysed. The highest number of nearly dead or dead plants was associated with coinfection by N. parvum or L. theobromae and M. phaseolina. For this reason, here, we designed bioassays with inoculations of N. parvum or L. theobromae, with and without M. phaseolina rhizosphere inoculation. The results indicated that canker disease severity increased due to root coinfection of M. phaseolina, depending on the N. parvum or L. theobromae inoculum and the blueberry cultivar. These findings show that the disease is more complex than previously thought, and should be considered in the development of more effective control measures.

韦尔瓦（西班牙）是欧洲最大的早春蓝莓生产国。韦尔瓦省的蓝莓田被精耕细作。蓝莓的溃疡病或枯萎病以及导致的枝条枯萎主要由葡萄球菌引起，已成为全世界蓝莓产区的一个严重问题。尽管与此疾病相关的葡萄球菌种类的存在有所不同。在韦尔瓦，蓝莓溃疡或茎枯病已被归因于Neofusicoccum孢子虫，N. AUSTRALE和Lasiodiplodia theobromae。同时，菜豆（Macrophomina phaseolina）与蓝莓木炭腐烂有关。由于葡萄孢菌属和菜豆分枝杆菌种而有溃疡和根腐病的植物分别被频繁发现。该观察结果导致考虑了这些感染的可能相互作用。因此，从溃疡病发生率高和严重程度高的农场中抽取了蓝莓植物，并对患病植物的茎和根进行了分析。几乎死亡或死亡的植物数量最高与小猪链球菌或L. theobromae和菜豆合并感染有关。因此，在这里，我们设计了接种小白猪笼草或Theobromae的生物分析，并伴有或不伴有菜豆分枝杆菌根际接种。结果表明，溃疡疾病的严重程度因根共感染增加M. phaseolina，这取决于N. parvum或L. theobromae接种物和蓝莓品种。这些发现表明，这种疾病比以前认为的要复杂，在制定更有效的控制措施时应考虑到这一点。