Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 2006
Publication Date: June 23, 2006
Citation: Jin, Y. 2006. Resistance to Race TTKS of Puccinia graminis f. sp. tritici in Chris and Related Spring Wheat. Phytopathology. 97:S162. Technical Abstract: Race TTKS (or Ug99) of Puccinia graminis f. sp. tritici, present in eastern Africa, is virulent to many stem rust resistance genes in wheat cultivars worldwide. Spring wheat cultivars AC Barrie, Chris, Thatcher and several other related wheat lines, were found to be resistant to race TTKS based on seedling tests. Chris and Thatcher were also highly resistant at the adult plant stage tested in Kenya. The inheritance of resistance to race TTKS was investigated using F2 populations of the resistant cultivars crossed with Chinese Spring and/or Marquis, genotypes susceptible to TTKS. The TTKS resistance in AC Barrie and Chris appeared to be controlled by two complementary recessive genes, and in Thatcher by three complementary recessive genes. While the inheritance of TTKS resistance in these wheat lines could be sufficiently explained by two to three complementary recessive genes, it is more likely that the low frequencies of resistant plants in the segregating populations are due to the presence of specific suppressors in the susceptible parents. F2 populations of intercrosses among AC Barrie, Chris and Thatcher did not segregate, indicating that they share the same resistance gene(s). These sources of resistance could be used to develop wheat cultivars resistant to race TTKS.