Postulation of seedling leaf rust resistance genes in 84 Chinese winter wheat cultivars

Abstract: Wheat rust caused by the fungus Puccinia triticina Eriks. is one of the most important leaf diseases of wheat (Triticum aestivum L.). The use of resistant varieties is the most economical and safest method of disease control. Knowledge of the resistance genes of the host plant greatly facilitates their effective use in breeding. The gene postulation method helps to quickly identify probable rust resistance genes (Lr genes) presented in a large number of wheat varieties at the same time. The aim of this work is to test the genes of juvenile resistance to brown rust, potentially present in 11 varieties of winter soft wheat sown in southern Russia, using ten isolates P. triticina. To identify resistance genes, types of damage (TD) by 10 fungus isolates on 11 varieties were compared with TD on a standard set of almost isogenic lines of Tatcher. If the stable reaction on the line and variety coincides with the majority of fungal isolates with different virulence, the corresponding gene of resistance of the line and variety is also matched. The resistance of varieties and lines to the pathogen in the phase of adult plants was evaluated in the experimental fields of the All-Russian Scientific Research Institute of Biological Plant Protection in 2017. Lr genes were postulated in ten varieties in juvenile stage: 2a, 3bg, B, 18, 20, 21, 25, 28, 29, 30, 32, 43, 45, 47. In the adult state of plants, Lr29, Lr32, Lr43, Lr45, Lr47 genes are effective to the North Caucasian population P. triticina. Varieties in which effective genes of resistance to brown rust have been postulated are recommended for further use in breeding and territorial distribution in southern Russia.

TL;DR: In this article , a genetic linkage map of LrCH1539 was constructed using the developed 2BS chromosome-specific markers, and its flanking markers were sxau-2BS136 and sxAU- 2BS81.

TL;DR: Wang et al. as discussed by the authors identified ten leaf rust resistance genes, Lr1, 9, 10, 19, 20, 24, 26, 34, 37 and 46, in 108 wheat cultivars from the Beijing and Shandong province and a set of 36 differentials, mostly near-isogenic lines in the background of Thatcher with known leaf rust resistant genes, were tested with 20 Puccinia triticina pathotypes.

TL;DR: In this article , a genetic linkage map of LrCH1539 was constructed using the developed 2BS chromosome-specific markers, and its flanking markers were sxau-2BS136 and Sxau 2BS81 .

TL;DR: The importance of leaf rust in the main wheat production areas as reflected by yield losses, the complexity of virulence variation in pathogen populations, the role cultivars with race-specific resistance play in pathogenic evolution, and the control measures currently practiced in various regions of the world are summarized.

TL;DR: One hundred and seventy-eight loci have been mapped in Triticum tauschii (Coss.), and a hypervariable sequence was identified, which may have potential use in varietal fingerprinting.

TL;DR: The conversion process of AFLP fragments to STS markers was technically difficult, mainly because of the presence of contaminating fragments, but a general verification strategy was formed prior to clone sequencing to reduce the frequency of false positives and to identify the correct clone.

TL;DR: Near-isogenic lines (NILs) for the leaf rust resistance gene Lr9 were screened for polymorphisms at the molecular level, proving their general applicability in wheat breeding programs.