ISOLATION AND CHARACTERIZATION OF PHOSPHATE-SOLUBILIZING FUNGI FROM SALINE REGION FOR INCREASED CROP PRODUCTIVITY

The study designed to isolate and characterize PSF from the saline rhizosphere of Avicennia marina, which is dominant mangrove species, to evaluate their potential as biofertilizer in saline soil of Kutch region. Eight fungal isolates from mangrove soils in Kandla, Gujarat, were identified as Alternaria alternata, Aspergillus fumigatus, Aspergillus versicolor, and Penicillium oxalicum species using 18S rRNA gene sequencing. Phosphate solubilization was measured using NBRIP and PVK medium. The development of plant growth assets particularly siderophore and indole acetic acid synthesis were investigated. The quantitative study of A. fumigatus (PSF-4) revealed the highest IAA synthesis (59.0 µg/ml), the strongest siderophore activity, and the highest phosphate solubilization ability (700 µg/ml in NBRIP and 680 µg/ml in PVK). Furthermore, A. versicolour (PSF-6) demonstrated considerable potential due to its growth-promoting and persistent solubilization characteristics. PSF-4 and PSF-6 exhibited the highest levels of plant growth-promoting characteristic which includes siderophore synthesis and indole-3-acetic acid (IAA), suggesting their dual activity. This result confirmed that native fungal isolates from soils related with mangroves have the potential to be effective bioinoculants for sustainable agriculture, especially in saline conditions.