GIBBERELLIN PRODUCTION BY ANTAGONISTIC FUNGUS STRAINS (Trichoderma harzianum)

Résumé

Trichoderma is one of the most important fungi in agriculture. It has demonstrated many capabilities to be used
as biofertilizers as well as bio-fungicides. It has also shown its sustainability and various mechanisms of
providing the crop with nutrients. It was reported to improve the plant growth of many crops. Six strains of
Trichoderma harzianum were isolated and identified in the laboratory of biopesticides in the National Institute of
Agronomic Research of Algeria (INRAA). All the obtained strains were tested for their capacity to produce
gibberellin. The results revealed that all the isolated strains have the ability to produce GA3 whereas the 1st strain
showed the production of GA3 with no difference between days. Unlike, the other strains showed very highly
significant production of GA3 between days. The production of GA3 reached the highest value after 14 days,
unlike the 7 and 21 days after. On the other hand, S2 presented the highest average for filtrate content of GA3
with 83 mg/100mL, followed by S with 76 mg/100mL, and S5 with 68 mg/100mL, while other isolates have
recorded the lowest average of 64, 75, and 48 mg/100mL