بررسي اثر چند باكتري آنتاگونيست در كلونيزاسيون ريشه و افزايش رشد گياه كلزا

A Study of the Effect of Some Antagonistic Bacteria Colonization on Root to Increase Canola (Brassica napus) Plant Growth

Seven Isolates of bacteria were studied for their ability to suppress canola (Brassica napus) damping-off, as caused by Rhizoctonia solani. Four bacterial species of Pseudomonas fluorecens (Isolates PI, P2, P3), Burkholderia cepacia (Isolate Bui), Bacillus subtilis (Isolates Bl, B2) and Streptomyces sp. (Isolate SI) were tested at greenhouse conditions against the pathogen. Seed and soil treatments with the seven bacterial isolates resulted in significant increased plant growth of canola and its reduced disease severity. Isolates applied to soil demonstrated a significantly higher increase in plant growth compared to seed treatments. Isolates PI, P2, P3, Bui caused a significant increase in plant fresh weight as well as in root growth. P3 Isolate was the most effective in increasing plant growth by an average of 13%, while P2 Isolate was also very effective in increasing growth and by an average of 11% as compared to control. PI, Bui, Bl, B2 and SI (respectively by 10, 10, 9, 7 and up to 6 %) increased plant growth as compared to control. Furthermore, all isolates were capable of colonizing canola root in the free from causal agent conditions, for which, P3 was determined as the strongest colonizer of canola root.