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Genetics of Leaf Rust Resistance in the Soft Red Winter Wheat ‘Caldwell’
Author(s) -
Kolmer J. A.
Publication year - 2009
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/cropsci2008.10.0598
Subject(s) - biology , backcrossing , rust (programming language) , seedling , inoculation , wheat leaf rust , cultivar , resistance (ecology) , botany , poaceae , horticulture , agronomy , gene , genetics , programming language , virulence , computer science
The soft red winter wheat ( Triticum aestivum L.) ‘Caldwell’ has effective resistance to leaf rust caused by Puccinia triticina . To determine the genetic basis of this resistance, Caldwell was crossed with the leaf rust–susceptible spring wheat ‘Thatcher’, and the F 1 plants were backcrossed to Thatcher to obtain backcross (BC) F 2 (BC 1 F 2 ) families. In the seedlings, the BC 1 F 2 families segregated for a single gene to P. triticina race SBDG, which is likely Lr14a based on tests with BC 1 F 3 lines. In field tests, the BC 1 F 2 families segregated for a single gene for adult plant resistance that was independent of the seedling resistance. BC 1 F 2 adult plants were inoculated in greenhouse tests with P. triticina races BBBD and THBJ, and resistant plants were selected and advanced by single‐seed descent to produce BC 1 F 4 lines. In greenhouse tests, adult plants of some of the BC 1 F 4 lines had the same low and high infection type (IT) to different P. triticina races as the Thatcher isoline with Lr12 Other BC 1 F 4 plants had intermediate IT to the P. triticina race THBJ. The BC 1 F 4 plants with the intermediate ITs were selected and tested as BC 1 F 5 adult plants in greenhouse tests and as BC 1 F 4:6 lines in field plot tests at two locations. Caldwell likely has the seedling resistance Lr14a, the adult plant gene Lr12 , and an uncharacterized adult plant resistance gene that conditions an intermediate level of effective resistance in field plots.