HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Kolmer, J. A. PubMed Articles by Kolmer, J. A. Agricola Articles by Kolmer, J. A. Related Collections Wheat Plant Disease Crop Genetics

CROP BREEDING & GENETICS

Genetics of Leaf Rust Resistance in the Soft Red Winter Wheat ‘Caldwell’

USDA-ARS, Cereal Disease Lab., St. Paul MN, 55108

^* Corresponding author (jkolmer{at}umn.edu).

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 F₁ plants were backcrossed to Thatcher to obtain backcross (BC) F₂ (BC₁F₂) families. In the seedlings, the BC₁F₂ families segregated for a single gene to P. triticina race SBDG, which is likely Lr14a based on tests with BC₁F₃ lines. In field tests, the BC₁F₂ families segregated for a single gene for adult plant resistance that was independent of the seedling resistance. BC₁F₂ 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 BC₁F₄ lines. In greenhouse tests, adult plants of some of the BC₁F₄ lines had the same low and high infection type (IT) to different P. triticina races as the Thatcher isoline with Lr12. Other BC₁F₄ plants had intermediate IT to the P. triticina race THBJ. The BC₁F₄ plants with the intermediate ITs were selected and tested as BC₁F₅ adult plants in greenhouse tests and as BC₁F_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.

Abbreviations: BC, backcross • IT, infection type • MR, moderately resistant • MS, moderately susceptible • R, resistant • S, susceptible