Citrus have been grown as a commercial fruit crop in Morocco for a decade. The area dedicated to growing and producing citrus has increased from 2006 to 2018 throughout the country. The rapid decline of citrus trees has been observed in many locations. Therefore, this study aimed to identify and characterize fungal pathogens associated with dry root rot (DRR) disease of citrus from diseased trees and soil collected from different citrus-growing plantations. Isolation and morphological identification of pathogens were performed using PDA-SC medium. Thirty-four Fusarium isolates were recovered from symptomatic plants. These isolates were identified based on morphological traits and the sequence of the internal transcribed spacer (ITS) region. Four Fusarium species were identified. Fusarium solani (Martius) was most frequently identified (70.60%), followed by F. oxysporum (17.65%), F. equiseti (8.82%) and F. brachygibbosum (2.94%). The two latter species have recently been associated with DRR in Morocco. Two separate pathogenicity trials were conducted to test the effect of the pathogens on young citrus seedlings. Results indicated that, with the exception of F. equiesti, Fusarium isolates were aggressive pathogens of citrange-Troyer and sour orange seedlings 2 months postinoculation. Citrus trees displayed key symptoms of DRR such as root rot, discolored and necrotic roots, purple wood discoloration, plant yellowing and general weakness. Further, all four species were able to induce lesions when they were used to inoculate citrus branches. This is the first detailed report of Fusarium species associated with DRR in Morocco.

柑桔已经在摩洛哥作为商业水果作物种植了十年。从2006年到2018年，全国柑桔种植和种植面积有所增加。在许多地方都观察到柑橘树的迅速衰退。因此，本研究旨在鉴定和表征与从不同的柑橘种植园收集的患病树木和土壤中的柑橘干根腐病（DRR）相关的真菌病原体。使用PDA-SC培养基进行病原体的分离和形态学鉴定。从有症状的植物中回收了34株镰刀菌。根据形态特征和内部转录间隔区（ITS）区域的序列鉴定这些分离株。确定了四种镰刀菌。茄病镰刀菌（马蒂乌斯）中最经常识别的（70.60％），其次是尖孢镰孢（17.65％），F.木贼（8.82％）和F. brachygibbosum（2.94％）。后两个物种最近在摩洛哥与DRR相关。进行了两个单独的致病性试验，以测试病原体对柑橘幼树的影响。结果表明，除F. equiesti外，镰刀菌分离物是接种后2个月的橘子小鸡和酸橙幼苗的侵袭性病原体。柑桔树显示出DRR的主要症状，例如根腐烂，根变色和坏死，紫木变色，植物变黄和总体无力。此外，当将这四个物种用于接种柑橘分支时，它们都能够诱发病变。这是摩洛哥与DRR相关的镰刀菌属物种的第一个详细报告。