TY - PRO AU - Lopez-Vera,E.E. AU - McIntosh,R. AU - Ruiz-Medrano,R. AU - Xoconostle-Cazares,B. AU - Huerta-Espino,J. AU - Sukhwinder-Singh AU - Singh,R.P. AU - Bhavani,S. TI - Mapping gene SrNiini effective against the Pgt race Ug99 group SN - 978-0-615-70429-6 PY - 2012/// N1 - Abstract only N2 - Wheat line Niini is resistant to the Pgt race Ug99 group at the seedling and adult plant stages. We conducted molecular mapping of resistance in an F5 population of 148 RILs from Cacuke/Niini (Pedigree: Ningmai 9558//Chilero/Chuanmai 18). The parents and RILs were phenotyped at Njoro, Kenya, in 2010. The field reactions of lines varied from R to MR-MS with a range of severities indicating that the expression of resistance was influenced by genetic background. The distribution of 70 homozygous resistant, 67 homozygous susceptible and 12 segregating RILs indicated single gene segregation. The resistance gene in Niini was temporarily designated SrNiini. Sixty resistant and 50 susceptible RILs with clear phenotypic differences were chosen for mapping using a bulked segregant analysis approach. SSR markers were used to screen the parental lines, and resistant and the susceptible bulks in the first instance, and then individual lines were analyzed with the polymorphic markers. SSR marker Xcfd49 on chromosome arm 6DS was 4.5 cM from the resistance gene. Further studies are needed to determine the relationship of Srniini and other Sr genes located on chromosome 6DS ER -