TABLE 4.

Chromosomal location in IBM map units and parameters associated with major quantitative trait loci (QTL), affecting lesion severity conferred by the Rp1-D21 gene

	Bin 1.05a				Bin 9.02				Bin 9.03				Bin 10.03
Trait	2 LOD intervalb	ac	LODd	R2(%)e	2 LOD interval	a	LOD	R2(%)	2 LOD interval	a	LOD	R2(%)	2 LOD interval	a	LOD	R2(%)
GH necrosis	463-473-482	0.21	8.9	14					241-249-257	0.16	5.2	8	174-179-185	0.23	11	19
IN necrosis													164-165-178	0.58	13	24
NC '07 necrosis									244-249-253	0.17	7.6	11	171-178-186	0.26	15.8	26
NC '08 necrosis					122-133.6-142	−0.14	5.4	7	235-248-253	0.12	5.4	6	176-180-183	0.24	17.8	23
Overall necrosis									238-250-253	0.13	6.6	7	176-178-181	0.25	21.3	26
GH height													168-173-188	0.05	4.3	1
IN height													162-165-167	0.1	11.1	25
NC '07 height													170-179-186	0.05	9.9	18
NC '08 height													165-180-196	0.02	8.4	13
Overall height									238-250-256	0.03	4.2	5	169-179-185	0.06	18	26
NC '07 anthesis													169-184-196	0.96	5.2	11

Data were derived from a population derived from a cross between the Rp1-D21-H95 maize line heterozygous for Rp1-D21 and 233 different lines from the B73 × Mo17 advanced intercross IBM population. The population was assessed in four environments: in a greenhouse in winter 2006 in Raleigh, North Carolina (denoted GH), in the field in West Lafayette, Indiana, in summer 2007 (IN), and in the field in Clayton, North Carolina, in summer 2007 and 2008 (NC '07 and NC '08). Three different traits were measured: lesion severity measured on a 1–5 scale (with 1 being complete absence of lesions and 5 being complete coverage of the ear leaf with lesions—denoted as “necrosis” in the table), the ratio between the average height of lesion mimic and wild-type individuals within each F₁ family (height), and the average divergence in time to anthesis in days between lesion mimic and wild-type individuals within each F₁ family (anthesis). Least-squares means for each F₁ family over the three field environments (IN, NC '07, NC '08) were used to calculate QTL for “overall necrosis” and “overall height.” These traits are shown in bold.

^aChromosome bin location of QTL peak on 1 of the 10 chromosomes of the maize genome. Bins divide the genetic map into 100 approximately equal segments. The segments are designated with the chromosome number followed by a two-digit decimal (e.g., 1.00, 1.01, 1.02, and so on).

^bThe two outer numbers report the positions that define the two LOD interval around the position of peak likelihood for the QTL. The middle number defines the position of the peak. All values are in IBM map units (IcM; see Balint-Kurti et al. 2007) and are based on the IBM2 map (http://www.maizegdb.org/map.php).

^cThe additive effect of the QTL. For necrosis ratings this is in terms of the 1–5 scale. For height ratings this is in terms of the ratio with “1” meaning a 1:1 ratio. For anthesis this is in terms of days. A positive number means the allele for decreased score (lower lesion level), increased ratio, or decreased anthesis differential derived from B73.

^dThe log of odds (LOD) value at the position of peak likelihood of the QTL.

^eR² estimates the proportion of phenotypic variance (%) explained by the detected QTL.