Fusarium wilt biocontrol and tomato growth stimulation, using endophytic bacteria naturally associated with Solanum sodomaeum and S. bonariense plants

Egyptian Journal of Biological Pest Control

Table 2 Antagonistic and plant growth-promoting (PGP) mechanisms of the seven selected endophytic bacterial isolates recovered from Solanum sodomaeum and Solanum bonariense

Solanum spp.	Bacterial isolates	Antagonistic traits				PGP ability
		Hydrolytic enzymes			Volatile antibiotic	PGP ability
		Chitinase^a	Protease^b	Pectinase^c	HCN^d	Phosphate solubilization^e	IAA^f
S. sodomaeum	S11	+	++	+	+	−	+
	S14	+	+	+	−	+	++
	S28	+	+	+	+	++	++
	S26	-	+	+	−	−	++
S. bonariense	S23	+	++	+	−	−	+++
	S24	+	++	+	−	−	+++
	SV81	+	−	+	−	+	+

S11, Azotobacter chroococcum; S14, Serratia marcescens; S23, S24, S26, and S28, Stenotrophomonas maltophilia; SV81, Bacillus sp.
^aTested on chitin-agar (0.5% w/v) medium and incubated at 28 ± 2 °C for 72 h; “+”, presence of clear zone; “−”, absence of clear zone
^bTested on skim milk agar (3% v/v) medium and incubated at 28 ± 2 °C for 48 h; “+” and “++”, presence of clear zone (15.67 to 25 and 30 to 45.83 mm in diameter, respectively); “−”, absence of clear zone
^cTested on pectin-agar (0.5% w/v) medium and incubated at 28 ± 2 °C for 48 h; “+”, presence of clear zone
^dHCN, hydrogen cyanide production on glycine-agar (4.4 g/L w/v) medium and incubated at 25 °C for 4 days; “+”, modification on the filter paper color (light-reddish color) compared to the control (yellow); “−”, no modification on the filter paper color (yellow)
^eTested on Pikovskaya agar medium and incubated at 28 ± 2 °C for 7 days; “+” and “++”, presence of clear zone (8.33–9.8 and 13.17 mm in diameter, respectively); “−”, absence of clear zone
^fIAA, indole-3-acetic acid production after 48 h of incubation at 28 ± 2 °C in Luria-Broth medium; “+”, “++”, and “+++”, production of IAA (5–9.4, 14.38–18.71, and 20.5–24.8 μg/ml, respectively)