Field Resistance to the Ug99 Race Group of the Stem Rust Pathogen in Spring Wheat Landraces

• DOI: 10.1094/pdis-02-12-0200-re
• Publication Date: 2012-11-07T19:46:06Z
• Authors: M. Newcomb; M. Acevedo; H. E. Bockelman; G. Brown-Guedira; B. J. Goates; E. W. Jackson; Y. Jin; P. Njau; M. N. Rouse; D. Singh; R. Wanyera; J. M. Bonman
• Keywords: Stem rust; Rust (programming language)

Wheat landraces provide a source of genetic variability for breeding. The emergence and spread highly virulent races the stem rust pathogen (Ug99 race group Puccinia graminis f. sp. tritici) threaten wheat production globally. Spring were screened resistance in eight field seasons at Kenya Agricultural Research Institute, Njoro, where Ug99 has become endemic. Accessions showing one season retested with molecular markers associated genes Sr2, Sr24, Sr36, Lr34/Yr18; two height-reducing genes; photoperiod insensitivity allele. Of 2,509 accessions tested, 278 categorized as resistant based on results from least seasons. these accessions, 32 positive or more Rht-B1b, Rht-D1b, indicating that they do not fit definition “landrace” because likely introduced via modern breeding practices. Thus, 246 identified. countries than five tested Afghanistan, Iran, Portugal, Ethiopia, Uzbekistan, Greece, Tajikistan, Bosnia Herzegovina, Serbia had 10% to group. Future research will characterize determine its novelty incorporate novel into improved lines.