Diversity, Biocontrol, and Plant Growth Promoting Abilities of Xylem Residing Bacteria from Solanaceous Crops

Table 3

In vitro inhibition of R. solanacearum and production of antagonistic compounds and plant growth promoting substances by XRB.

Strain	Haplotype	Inhibition of R. solanacearum	Volatile and diffusible inhibitory compounds				Plant growth promoting substances
		Radius in mm	HCN	Ammonia	Acetoin	Siderophore	Phosphate solubilisation	ACC deaminase^a	IAA^b  μg/mL
XB1	M80-7	2.83±0.29	−	−	−	−	−	+++	105.00±7.07
XB7	M80-27	3.33±0.58	+	−	−	+	+	−	47.73±3.21
XB8	M80-20	3.33±0.29	−	−	−	−	+	−	19.09±1.29
XB20	M80-20	3.27±0.40	−	−	−	−	+	−	25.45±1.71
XB27	M80-20	1.83±0.29	−	−	−	−	+	−	15.91±1.07
XB62	M80-31	8.17±0.76	+	−	−	−	+	++++	73.18±4.93
XB70	M80-15	3.83±0.58	−	−	−	−	−	−	171.82±11.57
XB86	M80-7	2.33±0.76	−	−	−	−	−	+++	66.82±4.50
XB93	M80-6	3.17±0.29	+	−	+	−	+	−	57.27±3.86
XB99	M80-9	6.83±0.58	−	+	+	−	+	−	321.36±21.64
XB100	M80-9	4.50±0.50	−	+	+	−	+	−	238.64±16.07
XB114	M80-31	6.50±0.50	−	−	−	+	+	−	89.09±6.00
XB122	M80-28	4.33±0.58	+	−	−	+	+	−	66.82±4.50
XB123	M80-31	3.00±0.87	−	+	+	−	+	−	416.82±28.07
XB126	M80-27	2.83±0.29	−	−	+	−	+	−	60.45±4.07
XB134	M80-37	1.57±0.12	−	+	+	−	+	−	645.91±43.50
XB140	M80-5	3.67±0.76	−	+	−	+	+	++++	50.91±3.43
XB153	M80-6	3.17±0.29	−	−	+	−	+	−	155.91±10.50
XB157	M80-6	2.50±1.00	−	−	+	−	+	−	184.55±12.43
XB165	M80-29	1.57±0.12	−	−	−	−	−	+	190.91±12.86
XB169	M80-6	1.53±0.06	−	−	−	−	−	−	15.91±1.07
XB170	M80-6	3.51±0.02	+	−	−	−	+	−	28.64±1.93
XB177	M80-6	1.99±0.49	−	−	−	−	−	−	76.36±5.14
XB196	M80-10	3.93±0.12	−	−	−	−	−	−	35.00±2.36
XB197	M80-38	4.33±0.29	−	−	+	−	−	−	41.36±2.79
XB200	M80-36	1.87±0.23	−	−	−	−	−	++	168.64±11.36
XB202	M80-31	4.67±0.21	−	−	−	−	+	+++	82.73±5.57
XB203	M80-31	3.67±0.29	−	−	−	−	−	−	70.00±4.71

Inhibition zones are mean of three replications and showing standard deviation. Inhibition zone was measured as radius from the outer edge of well. All the experiments were conducted at 28±2°C. + indicates presence of trait; − indicates absence of trait in plate based assays. ^aLevels of ACC deaminase activities based on growth on plate based assay denoted as + for less growth, +++ for moderate growth, +++ for luxuriant growth, and ++++ for highly luxuriant growth; ^bIAA was estimated in culture filtrate and expressed as 𝜇g/mL using analytical grade IAA as standard; values indicate mean and standard deviation.