Characterization of Leaf Rust Resistance in Hard Red Spring Wheat Cultivars

Abstract

Leaf rust, caused by Puccinia triticina Eriks., is the most common disease of wheat (Triticum aestivum L.) in the United States and worldwide. The objective of this study was to characterize seedling and adult plant leaf rust resistance in hard red spring wheat cultivars grown in Minnesota, North Dakota, and South Dakota, and postulate the identity of the seedling leaf rust resistance genes in the cultivars. Twenty-six cultivars, near-isogenic lines of Thatcher wheat that differ for single leaf rust resistance genes, and three wheat cultivars with known leaf rust resistance genes, were tested with 11 different isolates of leaf rust collected from the United States and Canada. The leaf rust infection types produced on seedling plants of the cultivars in greenhouse tests were compared with the infection types produced by the same isolates on the Thatcher near-isogenic lines to postulate which seedling leaf rust resistance genes were present. Seedling leaf rust resistance genes Lr1, Lr2a, Lr10, Lr16, Lr21, and Lr24 were postulated to be present in spring wheat cultivars. Seedling genes Lr3, Lr14a, and Lr23 likely were present in some cultivars but could not be clearly identified in this study. Most of the cultivars had some level of adult plant leaf rust resistance, most likely due to Lr34. Cultivars that had seedling resistance genes Lr1, Lr2a, Lr10, or Lr16 had poor to intermediate levels of leaf rust resistance in field plots. Cultivars with combinations of seedling resistance genes Lr16 and Lr24 with additional adult plant resistance were highly resistant to leaf rust.

Genetic analysis of rust resistance genes in global wheat cultivars: an overview

“…The Lr20 gene is very rare in Australian germplasm, American soft red winter wheat, and Argentinian germplasm [41,122]. The Lr1 gene has been most frequently recorded in Australian wheat cultivars, American hard red spring wheat, Mexican bread wheat, Chinese cultivars, and Indian and Pakistani wheat cultivars [122,179,[180][181][182], while this gene is rare in Argentinean germplasm [45]. The Lr10 is very common in international winter wheat nurseries, Indian and Pakistani wheat cultivars, Mexican bread wheat, and Brazilian and Argentinean wheat cultivars [44,45,[181][182][183].…”

Tolerance of wheat varieties seedlings by glyphosate accelerated degradation

“…Growth reduction by glyphosate of wheat varieties seedlings, LGR after 15 and maximum yellowing of first leafs after 10 days However, the effect of all specific Lr genes had to be ensured by parasite entrance across consequential water deficit in cell. Mostly the enhancement of the resistance with respect of durability of the trait was achieved by combinations of nonspecific and specific Lr genes (Kolmer 1996, Oelke & Kolmer 2004. The appearance was linked to temporary water deficit consequential in lower infection efficiency or decreased reaction type (De Vallavieille-Pop et al 1995, Niks & Dekens 1991, Jerkovic et al 2013b.…”

PCR-based molecular markers linked to the leaf rust resistance gene Lr19 in different bread wheat cultivars

“…One of the common and harmful diseases of cereal crops is brown leaf rust caused by basidium fungus Puccinia recondite f. sp. tritici [1][2][3].…”