Since the early 2000s, over 5000 hectares of guava orchards have been decimated in Brazil by guava decline. The disease has caused tens of millions of dollars in yield losses, the loss of thousands of jobs, and the closing of many fruit pulp-processing plants. Guava decline has been described as a synergistic interaction between the nematode Meloidogyne enterolobii and the fungus Fusarium solani. Nonetheless, the etiology of the disease has had to be reappraised because recent molecular studies have reassigned the whole ‘F. solani species complex’ to the genus Neocosmospora, with several plant-parasitic species being reclassified or synonymized. Hence, from a collection of ‘F. solani’ isolates associated with guava decline, we chose four of the most aggressive isolates, from which we sequenced RNA polymerase II subunit 1 (RPB1), RNA polymerase II subunit 2 (RPB2), and translation elongation factor 1-alpha (TEF1) genes. A GenBank® BLASTn search showed that the isolates belonged to Neocosmospora sp. Phylogenetic analyses using the maximum likelihood (ML) and Bayesian inference (BI) methods, with individual and combined datasets for TEF1, RPB1 and RPB2 genes, clustered all isolates within the N. falciformis clade, with maximum support in the ML and BI multilocus analyses. This and previous studies show that N. falciformis is the causal agent of guava decline and soybean sudden death syndrome, as well as of crown and root rots in other annual and perennial crops.

自2000年代初以来，由于番石榴的减少，巴西超过5,000公顷的番石榴果园被淘汰。该病害造成数千万美元的产量损失，数千个工作岗位的损失以及许多果肉加工厂的关闭。番石榴的衰弱被认为是线虫肠线虫和茄镰刀菌之间的协同相互作用。尽管如此，由于最近的分子研究已经将整个“茄茄F. solani种复合物”重新分配给了Neocosmospora属，因此不得不重新评估该病的病因，并重新分类或同义词化了几种植物寄生物。因此，来自' F. solani在与番石榴下降相关的菌株中，我们选择了四种最具攻击性的菌株，从中对RNA聚合酶II亚基1（RPB1），RNA聚合酶II亚基2（RPB2）和翻译延伸因子1-alpha（TEF1）基因进行了测序。GenBank®BLASTn搜索显示分离株属于Neocosmospora sp.。系统发育分析使用最大似然（ML）和贝叶斯推理（BI）的方法，具有用于个体和组合的数据集TEF1，RPB1和RPB2基因，该群集内的所有分离株N.阅览者进化枝，具有在ML和BI多位分析最大支持。这项研究和以前的研究表明镰状猪笼草是番石榴产量下降和大豆猝死综合症以及其他一年生和多年生作物冠腐病和根腐病的病因。