Chromosomal locations of the maize (Zea mays L.) HtP and rt genes that confer resistance to Exserohilum turcicum
Genetics and Molecular Biology
We used 125 microsatellite markers to genotype the maize (Zea mays L.) near isogenic lines (NIL) L30 HtPHtPRtRt and L30 htphtpRtRt and the L40 htphtprtrt line which contrast regarding the presence of the recently described dominant HtP and the recessive rt genes that confer resistance to Exserohilum turcicum. Five microsatellite markers revealed polymorphisms between the NIL and were considered candidate linked markers for the HtP resistance gene. Linkage was confirmed by bulked segregant
... ked segregant sample (BSS) analysis of 32 susceptible and 34 resistant plants from a BC 1 F 1 population derived from the cross (L30 HtPHtPRtRt x L40 htphtprtrt ) x L40 htphtprtrt . The bnlg198 and dupssr25 markers, both located on maize chromosome 2L (bin 2.08), were polymorphic between bulks. Linkage distances were estimated based on co-segregation data of the 32 susceptible plants and indicated distances of 28.7 centimorgans (cM) between HtP and bnlg198 and 23.5 cM between HtP and dupssr25. The same set of susceptible plants was also genotyped with markers polymorphic between L30 HtPHtPRtRt and L40 htphtprtrt in order to find markers linked to the rt gene. Marker bnlg197, from chromosome 3L (bin 3.06), was found linked to rt at a distance of 9.7 cM. This is the first report on the chromosomal locations of these newly described genes.