TABLE 1.

Quantification of X. axonopodis pv. citri in lesions from naturally infected plants by PCR using pGXIS as the competitive element

Sample	Speciesa	Sample type	% of pixels that were from the target sequenceb with a pGXIS concn (pg/μl) of:			Avg from different pGXIS concns (log10 CFU/ml)c
			1.5	0.15	0.015
S1a	Grapefruit	Leaf	34.2	46.4	100	5.8 ± 0.2
S1b	Grapefruit	Leaf	0	13.6	89.1	5.0 ± 0.3
5W	Lemon	Fruit	10.9	33.3	100	4.9 ± 0.6
5B	Lemon	Fruit	22.1	45.2	96.7	5.5 ± 0.4
S2W	Grapefruit	Leaf	39.1	49.9	100	6.0 ± 0.2
S3B	Grapefruit	Leaf	28.1	41.4	90.8	5.5 ± 0.2
8W	Grapefruit	Leaf	0	0	51.1	4.3
7B	Lemon	Leaf	25.6	36.7	93.0	5.4 ± 0.2
X00-00048	Persian lime	Leaf	0	12.8	85.8	5.0 ± 0.3
XI00-00080	Grapefruit	Fruit	0	0	0	<2.7
XI00-00075	Grapefruit	Fruit	0	0	0	<2.7
X00-12906	Mexican lime	Leaf	11.3	33.0	100	4.9 ± 0.6
XI00-143a	Sweet orange	Leaf	0	0	63.6	4.6
XI00-143b	Sweet orange	Leaf	0	0	70.1	4.8
X00-13042	Mexican	Leaf	38.4	52.5	100	6.1 ± 0.2
	Lime
X00-13043	Grapefruit	Leaf	34.5	37.1	100	5.6 ± 0.1
X00-13044	Lemon	Leaf	0	13.4	100	4.7

^aGrapefruit, Citrus paradisi (Macf.); lemon, C. limon (L) Burm. f.; Persian lime, C. latifolia Tan.; Mexican lime, C. aurantifolia (Christm.) Swing; sweet orange, C. sinensis (L.) Osbeck. 

^bPercentage of the pixels from PCR product obtained from the target sequence (222 bp) relative to the total number of pixels generated from target and pGXIS (400-bp) PCR products using three concentrations of pGXIS in PCRs. 

^cArithmetic mean and standard deviation obtained with the three bacterial concentrations calculated from the equation that resulted from each pGXIS concentration.