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Inheritance of Resistance to Stem Rust in ‘Triumph 64’ Winter Wheat
Author(s) -
Knott D. R.
Publication year - 2000
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2000.4051237x
Subject(s) - stem rust , biology , backcrossing , puccinia , resistance (ecology) , cultivar , gene , botany , rust (programming language) , inheritance (genetic algorithm) , genetics , horticulture , agronomy , mildew , computer science , programming language
The winter wheat ( Triticum aestivum L.) cultivar Triumph 64 has resistance to a number of races of stem rust ( Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn) and has been used as a supplementary differential in identifying stem rust races. Triumph 64 was crossed and backcrossed to a susceptible wheat, LMPG, to study the inheritance of its resistance to races MCC and LCB. Four additional backcrosses to LMPG were made to produce near‐isogenic lines (NILs) carrying the Triumph 64 genes for resistance to races MCC and LCB. Twenty‐two NILs were tested with isolates of 10 stem rust races to determine the number of genes for resistance that were present. The genetic study indicated that Triumph 64 carries two genes conditioning resistance to both races MCC and LCB, and four genes conditioning resistance only to LCB. However, the NILs produced from Triumph 64 appeared to carry at least nine Sr genes, six giving resistance to both races MCC and LCB, and only one giving resistance just to LCB. Furthermore, some of the NILs were resistant to races TMH(15B‐1) and TMH(15B‐4) to which Triumph 64 is susceptible. One possible explanation for the results is that Triumph 64 carries one or more suppressors that were lost during the backcrossing, allowing the suppressed Sr genes to be expressed. Four of the NILs were resistant to all 10 races of stem rust and should be useful in wheat breeding.