Cytogenetical studies in wheat. XIV. Sr8b for resistance to Puccinia graminis tritici

1986 ◽  
Vol 28 (2) ◽  
pp. 189-197 ◽  
Author(s):  
R. P. Singh ◽  
R. A. McIntosh

A recessive, hemizygous-ineffective gene for resistance to Puccinia graminis tritici in 'Barleta Benvenuto', 'Klein Titan', and 'Klein Cometa' was located on chromosome 6AS, was genetically independent of the 6A centromere and failed to recombine with Sr8 (r < 0.3% at P = 0.05). It was therefore designated Sr8b. The gene formerly known as Sr8 was redesignated Sr8a. Sr8b conferred adult-plant resistance to the strains used for field tests. 'Klein Cometa' possessed a second gene in chromosome 5D; this was identified as Sr30.Key words: Puccinia, Triticum, gene location, linkage, wheat, cytogenetics, rust resistance.

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 664-670 ◽  
Author(s):  
R. P. Singh ◽  
R. A. McIntosh

Resistance to Puccinia graminis tritici pathotype 34-1, 2, 3, 4, 5, 6, 7 in a South African wheat, W3757, was attributed to a dominant gene located in an alien (possibly Agropyron elongatum) chromosome that had substituted with wheat chromosome 6D. This gene, designated SrB, and present in two additional South African wheats, W3758 and W3759, conferred a high level of adult plant resistance to pathotypes used for field assessments. Because SrB is apparently different from other genes transferred from A. elongatum to wheat, its possible exploitation following translocation to a wheat chromosome seems warranted. Key words: Puccinia graminis tritici, Triticum aestivum, wheat cytogenetics, rust resistance, alien substitution line.


Plant Disease ◽  
2020 ◽  
Author(s):  
Yu Wu ◽  
Yuqi Wang ◽  
Fangjie Yao ◽  
Li Long ◽  
Jing Li ◽  
...  

Stripe rust (yellow rust), caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive diseases of wheat in the world. Chinese wheat landrace ‘Guangtoumai’ (GTM) exhibited a high-level resistance against predominant Pst races in China at the adult-plant stage. The objective of this research was to identify and map the major locus/loci for stripe rust resistance in GTM. A set of 212 recombinant inbred lines (RILs) was developed from a cross between GTM and Avocet S (AvS). The parents and RILs were evaluated in three field tests (2018, 2019, and 2020 at Chongzhou, Sichuan) with the currently predominant Pst races for final disease severity (FDS) and genotyped with the Wheat 55K SNP array to construct a genetic map with 1,031 SNP markers. A major locus, named QYr.GTM-5DL, was detected on chromosome 5DL in GTM. The locus was mapped in a 2.75 cM interval flanked by SNP markers AX-109855976 and AX-109453419, explaining up to 44.4% of the total phenotypic variation. Since no known Yr genes have been reported on chromosome 5DL, QYr.GTM-5DL is very likely a novel adult plant resistance (APR) locus. Haplotype analysis revealed that the resistance allele displayed enhanced levels of stripe rust resistance and is likely present in 5.3% of the 247 surveyed Chinese wheat landraces. The derived cleaved amplified polymorphic sequence (dCAPS) marker dCAPS-5722, converted from a SNP marker tightly linked to QYr.GTM-5DL with 0.3 cM, was validated on a subset of RILs and 48 commercial wheat cultivars developed in Sichuan. The results indicated that QYr.GTM-5DL with its linked dCAPS marker could be used in marker-assisted selection to improve stripe rust resistance in breeding programs, and this QTL will provide new and possibly durable resistance to stripe rust.


2010 ◽  
Vol 61 (12) ◽  
pp. 1036 ◽  
Author(s):  
J. Zhang ◽  
C. R. Wellings ◽  
R. A. McIntosh ◽  
R. F. Park

Seedling resistances to stem rust, leaf rust and stripe rust were evaluated in the 37th International Triticale Screening Nursery, distributed by the International Wheat and Maize Improvement Centre (CIMMYT) in 2005. In stem rust tests, 12 and 69 of a total of 81 entries were postulated to carry Sr27 and SrSatu, respectively. When compared with previous studies of CIMMYT triticale nurseries distributed from 1980 to 1986 and 1991 to 1993, the results suggest a lack of expansion in the diversity of stem rust resistance. A total of 62 of 64 entries were resistant to five leaf rust pathotypes. In stripe rust tests, ~93% of the lines were postulated to carry Yr9 alone or in combination with other genes. The absence of Lr26 in these entries indicated that Yr9 and Lr26 are not genetically associated in triticale. A high proportion of nursery entries (63%) were postulated to carry an uncharacterised gene, YrJackie. The 13 lines resistant to stripe rust and the 62 entries resistant to leaf rust represent potentially useful sources of seedling resistance in developing new triticale cultivars. Field rust tests are needed to verify if seedling susceptible entries also carry adult plant resistance.


Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 269-276
Author(s):  
M. Padidam ◽  
D. R. Knott

Resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks, and Henn.), particularly adult plant resisitance to race 15B-1, was studied in seven wheat (Triticum aestivum L.) cultivars or lines: 'Bonza', 'Chris', 'FKN-II-50-17', 'MRFY', 'Thatcher', 'Marquillo', and 'Hope'. Each of the seven was crossed with a susceptible parent and either F4- or F5-derived lines developed by single seed descent. All of the lines were tested with race 15B-1 in field nurseries. Lines derived from parents carrying seedling resistance to race 15B-1 were also tested as seedlings in the greenhouse with race 15B-1, and in some cases races 56, 29, and C65. The data indicated that 'Bonza' carries Sr6, probably Sr5, an unidentified gene giving resistance to race 56, two unidentified genes for resistance to race C65, and two minor genes that combine to produce intermediate adult plant resistance. 'Chris' carries Sr5, Sr7a, Sr8a, and Sr12. In addition, it may have three minor genes for adult plant resistance. 'FKN-II-50-17' carries Sr6 and may have four minor genes that combine to produce moderate adult plant resistance. 'MRFY', which is seedling susceptible to race 15B-1, carries Sr9b, possibly Sr5, plus an unidentified gene for resistance to C65. In addition, it appears to have one major gene for adult plant resistance plus two or more minor genes. 'Thatcher', 'Marquillo', and 'Hope' had only limited resistance to race 15B-1 in the field and no genetic analysis of their crosses was possible. The four parents that had good resistance to race 15B-1 in the field, 'Bonza', 'Chris', 'FKN-II-50-17', and 'MRFY', all carry minor genes for adult plant resistance that had little effect individually but produced moderate resistance when combined. The genes Sr5 and Sr9b, which have no effect on resistance to 15B-1 is seedlings, were found to significantly increase resistance in adult plants in the field.Key words: stem rust, Puccinia graminis tritici, wheat, Triticum aestivum, adult plant rust resistance.


1988 ◽  
Vol 68 (3) ◽  
pp. 633-639 ◽  
Author(s):  
P. L. DYCK ◽  
O. M. LUKOW

Gene Lr29 transferred from Agropyron elongatum to chromosome 7D of wheat and gene LrVPM transferred from VPM1 both segregated as single genes for seedling resistance to leaf rust when backcrossed into common wheat (Triticum aestivum). Although the seedling resistance of the VPM lines was intermediate, their adult plant resistance was excellent. This resistance was not on chromosome 7D. The VPM lines also had seedling and adult plant resistance to stem rust. Resistant backcross lines with either Lr29 or LrVPM had higher kernel protein levels than did susceptible sister lines under both rust and rust-free conditions. Although this higher protein content was associated with weaker dough mixing properties, the remix loaf volume remained constant. Leaf rust infection had a detrimental effect on grain yield and kernel weight and on wheat quality as shown by decreased kernel protein content and farinograph absorption. Dough mixing strength was higher for the rust infected lines than the rust resistant lines.Key words: Triticum aestivum, wheat (spring), leaf rust resistance, protein content, breadmaking quality


2020 ◽  
Author(s):  
Yuqi Wang ◽  
Can Yu ◽  
Yukun Cheng ◽  
Fangjie Yao ◽  
Li Long ◽  
...  

Abstract Background: Stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), is a serious foliar disease of wheat. Identification of novel stripe rust resistance genes and cultivation of resistant varieties are considered to be the most effective approaches to control this disease. In this study, we evaluated the infection type (IT), disease severity (DS) and area under the disease progress curve (AUDPC) of 143 Chinese wheat landrace accessions for stripe rust resistance. Assessments were undertaken in five environments at the adult-plant stage with Pst mixture races under field conditions, in addition, IT was assessed at the seedling stage with two prevalent Pst races (CYR32 and CYR34) under controlled greenhouse conditions.Results: Seventeen accessions showed stable high-level resistance to stripe rust across all environments under field tests, while four accessions showed resistance to the Pst races CYR32 and CYR34 at the seedling stage. Combining phenotypic data from the field and greenhouse trials with 6404 markers covering the whole genome, we detected 17 quantitative trait loci (QTL) on 11 chromosomes for IT associated with seedling resistance and 15 QTL on seven chromosomes for IT, final disease severity (FDS) or AUDPC associated with adult-plant resistance. Four stable QTL detected on four chromosomes, which explained 9.99%–23.30% of the phenotypic variation, were simultaneously associated with seedling and adult-plant resistance. Integrating a linkage map of stripe rust resistance in wheat, 27 QTL overlapped with previously reported genes or QTL, while four and one QTL conferring seedling and adult-plant resistance respectively were mapped distantly from previously reported stripe rust resistance genes or QTL and may be novel resistance loci.Conclusions: Our results provided an integrated view of stripe rust resistance resources in a Chinese wheat landrace diversity panel from the southern autumn-sown spring wheat zone. The identified resistant accessions and resistance loci will be useful in the ongoing effort to develop new wheat cultivars with strong resistance to stripe rust.


2020 ◽  
Author(s):  
Yuqi Wang ◽  
Can Yu ◽  
Yukun Cheng ◽  
Fangjie Yao ◽  
Li Long ◽  
...  

Abstract Background: Stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), is a serious foliar disease of wheat. Identification of novel stripe rust resistance genes and cultivation of resistant varieties are considered to be the most effective approaches to control this disease. In this study, we evaluated the infection type (IT), disease severity (DS) and area under the disease progress curve (AUDPC) of 143 Chinese wheat landrace accessions for stripe rust resistance. Assessments were undertaken in five environments at the adult-plant stage with Pst mixture races under field conditions, in addition, IT was assessed at the seedling stage with two prevalent Pst races (CYR32 and CYR34) under controlled greenhouse conditions. Results: Seventeen accessions showed stable high-level resistance to stripe rust across all environments under field tests, while four accessions showed resistance to the Pst races CYR32 and CYR34 at the seedling stage. Combining phenotypic data from the field and greenhouse trials with 6404 markers covering the whole genome, we detected 17 quantitative trait loci (QTL) on 11 chromosomes for IT associated with seedling resistance and 15 QTL on seven chromosomes for IT, final disease severity (FDS) or AUDPC associated with adult-plant resistance. Four stable QTL detected on four chromosomes, which explained 9.99%–23.30% of the phenotypic variation, were simultaneously associated with seedling and adult-plant resistance. Integrating a linkage map of stripe rust resistance in wheat, 27 QTL overlapped with previously reported genes or QTL, while four and one QTL conferring seedling and adult-plant resistance respectively were mapped distantly from previously reported stripe rust resistance genes or QTL and may be novel resistance loci. Conclusions: Our results provided an integrated view of stripe rust resistance resources in a Chinese wheat landrace diversity panel from the southern autumn-sown spring wheat zone. The identified resistant accessions and resistance loci will be useful in the ongoing effort to develop new wheat cultivars with strong resistance to stripe rust.


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