Inheritance of New Stem Rust Resistance in CHAM-6/WW1402 Spring Wheat.

Abstract

The wheat stem rust pathogen, Puccinia graminis f. sp. tritici Eriks.& E. Henn (Pgt) can potentially devastate wheat (Triticum aestivum L.) crops globally.  Resistant wheat cultivars are an important component of minimizing crop damage caused by Pgt.  A stem rust resistant plant selection of the spring wheat line CHAM-6/WW1402, developed at CIMMYT, is moderately resistant to Indiana isolates of Pgt.  A population of recombinant inbred lines (RIL) from the cross of CHAM-6/WW1402 X 6HRW’SN125 (susceptible) was developed and characterized for resistance to local isolates of Pgt in field tests in 2009 (F_2:3) and in 2010 (F_5:6) at Lafayette, Indiana. Segregation for resistance in the RI population in the two respective tests, as determined by the Chi-square test for goodness of fit, indicated that resistance of CHAM6/WW1402 is conferred by one gene and resistance is dominant. SSR markers that are polymorphic on the parent lines, and resistant and susceptible bulks of, respectively, 8 RILs have been identified, and will be used to map the stem resistance of CHAM-6/WW1402.  Markers that co-segregate with the new stem rust resistance will be useful for marker-assisted selection for this resistance in wheat improvement.