ABSTRACT

Teratosphaeria stem canker is one of the most important diseases to have emerged on non-native plantation-grown Eucalyptus trees cultivated globally. The study assessed the pathogenicity of two Teratosphaeria species associated with Teratosphaeria stem canker and the susceptibility of Eucalyptus grandis and six commonly grown Eucalyptus hybrids to these fungal species in Uganda. The inoculation trials indicated that Eucalyptus species and hybrids were susceptible to fungal pathogens used. A comparison of Eucalyptus species and hybrids for each fungal species showed that GC 540 and GC 796/2 are the most susceptible hybrids to T. zuluensis and T. gauchensis respectively while hybrid clone GU 8 had a higher tolerance to both fungal species. GC 540 was also tolerant to T. gauchensis while F2 and GC 550 were tolerant to T. zuluensis. Eucalyptus grandis sourced from Australia (F2) showed a higher tolerance than Eucalyptus grandis from South Africa (F1). The results further revealed that both Teratosphaeria zuluensis and Teratosphaeria gauchensis are pathogenic to Eucalyptus species and hybrids. The generated information indicates that there is an opportunity to sustainably manage Teratosphaeria stem canker disease if tolerant species are grown in areas with high disease impact.

摘要

Teratosphaeria茎溃疡病是在全球范围内种植的非本地种植的桉树上出现的最重要疾病之一。这项研究评估了与乌贼属茎枯萎病相关的两种乌贼属物种的致病性，以及乌干达的巨桉桉树和六种通常生长的桉树杂种对这些真菌的敏感性。接种试验表明，桉树种和杂种对所使用的真菌病原体敏感。对桉树种和每种真菌种的杂种进行的比较表明，GC 540和GC 796/2是祖鲁木棉和斑节对虾最易感的杂种。高加索氏菌分别与杂种无性系GU 8对两种真菌都有较高的耐受性。GC 540也耐受高棉锥虫（T. gauchensis），而F2和GC 550则耐受T. zuluensis。来自澳大利亚的桉树（F2）的耐受性高于来自南非的桉树（F1）。结果进一步表明，祖鲁氏小球藻和高赤氏小球藻均对桉树种和杂种致病。所产生的信息表明，如果在疾病影响大的地区种植耐受性物种，就有机会可持续地管理红球菌干枯病。