Abstract: Many analytic strategies have emerged to estimate plant responses to Fusarium wilt. The demand for fast and reliable
method (diagnosis, prediction) to determine isolate strength accurately is not established yet. Early determination of pathogen
strength helps in plant medication. The aim of this study was to develop a faster strategy and method for early determination of
fungal isolates strength in correlation to plant response. Till now, the scientists have no consensus on the most correlated parameters
that could express wilt precisely. In this study, 30 isolates of Fusarium oxysporum isolated from Lupinus termis L. were used to
provide an explicit image about the real strength of Fusarium isolates and its impact on the plant. Wilting percentage ranged from
26.67% to 93.33% of the infected plants depending on isolate virulence. Some of cellular, morphological and physical measurements
were conducted on 8 out of 30 isolates, including root (length, fresh weight (FW) and dry weight (DW)), nodules (water content
(WC), FW, DW), stem (height, WC, FW, DW), total leaves/plant (WC, FW, DW) and the fourth leaf (WC, FW, DW, leaf area,
epidermal cell area, epidermal cell number, succulence). Hierarchical clustering was used to determine the variance between the
isolates. Detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) were used to determine the most
important growth parameters that could express wilting accurately. The CCA results showed that most of the measured parameters on
the fourth leaf, except for leaf epidermal cell number, were highly and positively correlated to wilt. That makes these specific
parameters valuable and sensitive for any changes in isolates strength. Accordingly, a mathematical model was created to be helpful
in the quick determination of isolate strength and precise medication.