Molecular Identification of Fusarium solani and β-Aminobutyric Acid (BABA)-Induced Resistance in Tomato (Solanum lycopersicum L.)

الملخص

This study aimed to investigate the molecular diversity of the plant pathogen Fusarium solani using molecular techniques, specifically polymerase chain reaction (PCR), due to its high accuracy compared to conventional morphological identification of fungal pathogens in tomato plants. The internal transcribed spacer regions (ITS1 and ITS4) within ribosomal DNA (rDNA) were targeted for identification.

Sequence analysis and comparison with reference sequences available in the NCBI GenBank database confirmed that the studied isolate represents a newly recorded isolate in Iraq, registered under the accession number (PV616682).

Pathogenicity tests of F. solani showed a significant reduction in seed germination percentage of tomato cultivar Mansoura F1. Germination rates decreased to 73.33% in Petri dishes and 90.00% in plastic pots, compared to the control treatment, which recorded 100% and 96.66%, respectively. Inhibition percentages reached 26.7% in Petri dishes and 20.0% in pots, whereas the control recorded 0% and 3.34%, respectively.

The results further demonstrated that treatment with β-Aminobutyric Acid (BABA) effectively induced systemic resistance in tomato plants by activating key defense-related enzymes, namely Peroxidase (POX) and Catalase (CAT). The combined treatment (F. solani + BABA) recorded the highest enzyme activity levels (2.56 and 2.45, respectively), compared to the control (1.49 and 1.38, respectively), at a significance level of 0.05.