TABLE 1.

The diversity of the Rp1-D21-mediated HR in maize

	Indiana scores		NC scores
Cross	Height ratio	Necrosis score	Height ratio	Necrosis score
A632 × Rp1-D21-H95	0.8	1.5	0.67	2.3
B73 × Rp1-D21-H95	0.64	4	0.74	2.2
B97 × Rp1-D21-H95	0.82	2	0.73	3.4
CM103 × Rp1-D21-H95	0.23	7	0.50	5.6
CML228 × Rp1-D21-H95	0.73	3.5	0.89	1.9
CML322 × Rp1-D21-H95	0	10	0.32	7.2
CML333 × Rp1-D21-H95	0.4	4	0.69	3.1
CML69 × Rp1-D21-H95	0.48	6	—	—
CML277 × Rp1-D21-H95	0.19	7	0.62	3.6
CML247 × Rp1-D21-H95	0.73	3	—	—
IL14H × Rp1-D21-H95	0.22	8	0.60	5.7
Ki3 × Rp1-D21-H95	0	10	0.35	6.4
Ki11 × Rp1-D21-H95	0.73	3	—	—
Ky21 × Rp1-D21-H95	0.18	9	0.37	6.6
M162W × Rp1-D21-H95	0	10	0.30	7.8
M37W × Rp1-D21-H95	0	10	0	10
Mo17 × Rp1-D21-H95	0.39	6	0.48	6.3
Mo18w × Rp1-D21-H95	0.68	3	0.66	4.3
MS-71 × Rp1-D21-H95	0.35	6.5	0.82	5.2
NC350 × Rp1-D21-H95	0	10	0	10
NC358 × Rp1-D21-H95	0.44	6	0.72	5.1
Oh43 × Rp1-D21-H95	0.76	3.5	0.89	2.7
Oh7B × Rp1-D21-H95	0.68	3	—	—
P39 × Rp1-D21-H95	0	10	—	—
Tx303 × Rp1-D21-H95	0	10	0.34	6.3
Tzi8 × Rp1-D21-H95	0.51	4.5	0.81	3.9

F₁ families were derived from crosses between a number of inbreds and the Rp1-D21-H95 line, which was heterozygous for the Rp1-D21 gene. The resulting F₁ families therefore segregated 1:1 for the necrotic spotting phenotype associated with Rp1-D21. The height ratio was the ratio between the average height of the mutant and wild-type plants within a family. If all the mutant plants died as seedlings the height ratio was reported as 0. This was measured in Clayton, North Carolina, in 2006. The same families were planted in West Lafayette, Indiana, in 2009. In this case severity scores were taken on a 0–10 scale with 0 being no lesions at all and 10 being dead.