The present work was initiated in order to test whether the growth and pathogenic behavior of fungal isolates infecting Faba bean (FB) are influenced by salt and drought stress. A collection of 108 fungal isolates was recovered from different infected FB plants grown in various bioclimatic zones in Tunisia. Koch’s postulates revealed that 54% of those isolates caused root rots infection by 25% to 100% of the whole root system. Eighteen pathogenic fungal isolates were chosen based on their high incidence on various plant growth parameters using the heat map analysis to undergo the in vitro analysis, where 13 isolates belong to Fusarium spp. The in vitro mycelial growth of the 18 strains in potato-dextrose agar amended with NaCl and PEG6000 was strain dependent, in which F. equiseti (VFF12, VFF16), F. graminearum VFF6, F. brachygibbosum VFF9, Alternaria sp. VFF5, Boeremia exigua VFF4, Rutstroemia sp. VFF7 and Rhizopus oryzae VFF1 showed a significant increase by up to 150% compared to controls. Best linear unbiased predictors (BLUPs) for differences in root and shoot dry weights between control (inoculated unstressed plants) and inoculated under salt and drought stress of the tolerant fungal strains were analyzed. BLUPs of VFF16, VFF6, and VFF7 were significantly increased under both stresses compared to controls. While, BLUBs of VFF12, VFF9, and VFF4 were not significant, which maintained similar pathogenic effect. However, BLUPs of VFF5 and VFF1 were significantly decreased. Consequently, soil salinization and water deficiency - occurring nowadays in many parts of the world - can increase the aggressiveness of phytopathogenic fungi.

开展本研究工作是为了测试盐和干旱胁迫是否会影响感染蚕豆（FB）的真菌分离株的生长和致病行为。从突尼斯各个生物气候带中生长的不同感染的FB植物中回收了108种真菌分离株。科赫的假设表明，这些分离株中有54％引起根腐病感染，占整个根系的25％至100％。根据其在各种植物生长参数上的高发生率，使用热图分析选择了18种病原性真菌分离株进行体外分析，其中13个分离株属于镰孢属。用NaCl和PEG6000修饰的18种马铃薯葡萄糖琼脂菌株的体外菌丝生长依赖菌株，其中马F木（F. equiseti）（VFF12，VFF16），禾谷镰刀菌VFF6，短臂镰刀菌VFF9，链格孢菌。VFF5，Exigua Boeremia，VFF4，Rutstroemia sp.。VFF7和米根霉与对照组相比，VFF1显着提高了150％。分析了对照（接种无胁迫植物）与耐性真菌菌株在盐和干旱胁迫下接种后根和茎干重量差异的最佳线性无偏预测因子（BLUP）。与对照相比，在两种压力下，VFF16，VFF6和VFF7的BLUP均显着增加。同时，VFF12，VFF9和VFF4的BLUB并不显着，其维持相似的致病作用。但是，VFF5和VFF1的BLUP显着降低。因此，当今世界许多地方都发生的土壤盐碱化和缺水会增加植物致病真菌的侵略性。