. 2010 Mar 5;76(9):2697–2703. doi: 10.1128/AEM.02697-09

TABLE 2.

Contamination rates and numbers of positive samples detected using seed macerates of infected seed lots

Seeds	Assay	No. of seed samples	Multiplex nested PCR detection		Semiselective isolation		No. of lots detected by both methods
Seeds	Assay	No. of seed samples	CR (%)	No. of positive lots	CR (%)	No. of positive lots	No. of lots detected by both methods
Seed lot P2 (CR, 1/10,000)^a	Assay 1	35	0.000077	6	0.000050	4	3
	Assay 2	35	0.000121	9	0.000012	1	1
	Mean		0.000099		0.000031
Seed lot P2 mixed with healthy seeds (1:1.1) (CR, 1/21,000)^b	Assay 1	35	0.000050	4	0.000000	0	0
	Assay 2	35	0.000037	3	0.000024	2	0
	Mean		0.000043		0.000012
Seed lot P2 mixed with healthy seeds (1:2) (CR, 1/30,000)^b	Assay 1	35	0.000037	3	0.000000	0	0
Seed lot P2 mixed with healthy seeds (1:2) (CR, 1/30,000)^b	Assay 2	35	0.000037	3	0,000012	1	0
	Mean		0.000037		0.000006
Seed lot P2 mixed with healthy seeds (1:12.8) (CR, 1/138.000)^b	Assay 1	35	0.000000	0	0.000012	1	0
	Assay 2	35	0.000000	0	0.000000	0	0
	Assay 3	35	0.000037	3	0.000012	1	0
	Mean		0.000012		0.000008
Healthy seeds	Assay 1	35	0.000000	0	0.000000	0
	Assay 2	35	0.000000	0	0.000000	0

The seed contamination rate was determined by multiplex nested PCR analyses.

The theoretical seed contamination rate was obtained by diluting seed lot P2 with healthy seeds.