scholarly journals Lr72 Confers Resistance to Leaf Rust in Durum Wheat Cultivar Atil C2000

Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 631-635 ◽  
Author(s):  
S. A. Herrera-Foessel ◽  
J. Huerta-Espino ◽  
V. Calvo-Salazar ◽  
C. X. Lan ◽  
R. P. Singh

Leaf rust, caused by Puccinia triticina (Pt), has become a globally important disease for durum wheat (Triticum turgidum subsp. durum) since the detection of race group BBG/BN, which renders ineffective a widely deployed seedling resistance gene present in several popular cultivars including Mexican cultivars Altar C84 and Atil C2000. The resistance gene continues to play a key role in protecting durum wheat against bread wheat–predominant races since virulence among this race group has not been found. We developed F3 and F5 mapping populations from a cross between Atil C2000 and the susceptible line Atred #1. Resistance was characterized by greenhouse seedling tests using three Pt races. Segregation tests indicated the presence of a single gene, which was mapped to the distal end of 7BS by bulk segregant analysis. The closest marker, wmc606, was located 5.5 cM proximal to the gene. No known leaf rust resistance genes are reported in this region; this gene was therefore designated as Lr72. The presence of Lr72 was further investigated in greenhouse tests in a collection of durum wheat using 13 Pt races. It was concluded that at least one additional gene protects durum wheat from bread wheat–predominant Pt races.

2014 ◽  
Vol 104 (12) ◽  
pp. 1322-1328 ◽  
Author(s):  
Alexander Loladze ◽  
Dhouha Kthiri ◽  
Curtis Pozniak ◽  
Karim Ammar

Leaf rust, caused by Puccinia triticina, is one of the main fungal diseases limiting durum wheat production. This study aimed to characterize previously undescribed genes for leaf rust resistance in durum wheat. Six different resistant durum genotypes were crossed to two susceptible International Maize and Wheat Improvement Center (CIMMYT) lines and the resulting F1, F2, and F3 progenies were evaluated for leaf rust reactions in the field and under greenhouse conditions. In addition, allelism tests were conducted. The results of the study indicated that most genotypes carried single effective dominant or recessive seedling resistance genes; the only exception to this was genotype Gaza, which carried one adult plant and one seedling resistance gene. In addition, it was concluded that the resistance genes identified in the current study were neither allelic to LrCamayo or Lr61, nor were they related to Lr3 or Lr14a, the genes that already are either ineffective or are considered to be vulnerable for breeding purposes. A complicated allelic or linkage relationship between the identified genes is discussed. The results of the study will be useful for breeding for durable resistance by creating polygenic complexes.


Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 809-814 ◽  
Author(s):  
S. A. Herrera-Foessel ◽  
R. P. Singh ◽  
J. Huerta-Espino ◽  
J. Yuen ◽  
A. Djurle

Leaf rust, caused by Puccinia triticina, has become an important disease of durum wheat (Triticum turgidum) in Mexico since the detection in 2001 of BBG/BN, a new race virulent on all common cultivars and on more than 80% of CIMMYT's durum wheat collection. We investigated the genetic basis and diversity of resistance in nine durum genotypes that are highly resistant to the new race. These resistant durums were crossed with the susceptible cv. Atil C2000 and intercrossed in a half diallel arrangement. Five diverse sources of resistance were identified by evaluating parents, F1, F2, and F3 populations in greenhouse and/or field trials under artificial epidemics of race BBG/BN. The same pair of partially dominant complementary genes determined resistance in Jupare C2001, Hualita, and Pohowera. Somateria and Llareta INIA shared the same dominant resistance gene, whereas a partially dominant gene conferred resistance in two sister lines, Guayacan 2 and Guayacan INIA. A different partially dominant gene present in Storlom was linked in repulsion to another partially dominant gene in Camayo. These diverse resistance genes can be used effectively to control leaf rust, preferably by deploying them in combinations.


2019 ◽  
Vol 79 (01) ◽  
Author(s):  
T. L. Prakasha ◽  
S. Chand ◽  
A. N. Mishra ◽  
K. S. Solanki ◽  
J. B. Singh ◽  
...  

This study aimed to investigate the genetic basis of leafrust resistance in three bread wheat cultivars viz., MP 3288, HI 1418 and HI 784 which have been maintaining high levels of resistance to leaf rust since their release in 2011, 2000, and 1983, respectively. These cultivars also possess leaf tip necrosis phenotype. These were crossed with a susceptible bread wheat cultivar Lal Bahadur and also among themselves in non-reciprocal manner.The F1 , F2 and F3 populations were raised and the inheritance of leaf rust resistance was studied using prevalent and highly virulent Puccinia triticina pathotype 77-5 (121R63-1) during 2014- 17. These studies showed that the field (adult-plant) resistance of these cultivars is governed by two dominant genes each. Closely linked molecular markers L34DINT9F and L34PLUSR revealed the presence of non-race specific adult-plant leaf rust resistance gene Lr34 in all cultivars of present study. Absence of the other documented race nonspecific APR genes viz., Lr46, Lr67 and Lr68 was indicated in all the three test cultivars based on genotyping with closely linked molecular markers WMC44, CFD71 and csgs, respectively. The other dominant gene appears to be an allstage resistance gene since all the three cultivars displayed high levels of seedling resistance to the test pathotype. Stable resistance of these cultivars could be due to synergistic/additive or complementary effects resulting from the combination of Lr34 and the all-stage resistance gene.


2018 ◽  
Vol 45 (10) ◽  
pp. 1046 ◽  
Author(s):  
Chanchal Sharma ◽  
Gautam Saripalli ◽  
Santosh Kumar ◽  
Tinku Gautam ◽  
Avneesh Kumar ◽  
...  

Leaf rust disease causes severe yield losses in wheat throughout the world. During the present study, high-throughput RNA-Seq analysis was used to gain insights into the role of Lr28 gene in imparting seedling leaf rust resistance in wheat. Differential expression analysis was conducted using a pair of near-isogenic lines (NILs) (HD 2329 and HD 2329 + Lr28) at early (0 h before inoculation (hbi), 24 and 48 h after inoculation (hai)) and late stages (72, 96 and 168 hai) after inoculation with a virulent pathotype of pathogen Puccinia triticina. Expression of a large number of genes was found to be affected due to the presence/absence of Lr28. Gene ontology analysis of the differentially expressed transcripts suggested enrichment of transcripts involved in carbohydrate and amino acid metabolism, oxidative stress and hormone metabolism, in resistant and/or susceptible NILs. Genes encoding receptor like kinases (RLKs) (including ATP binding; serine threonine kinases) and other kinases were the most abundant class of genes, whose expression was affected. Genes involved in reactive oxygen species (ROS) homeostasis and several genes encoding transcription factors (TFs) (most abundant being WRKY TFs) were also identified along with some ncRNAs and histone variants. Quantitative real-time PCR was also used for validation of 39 representative selected genes. In the long term, the present study should prove useful in developing leaf rust resistant wheat cultivars through molecular breeding.


Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 363-372 ◽  
Author(s):  
Zahra Nemati ◽  
Reza Mostowfizadeh-Ghalamfarsa ◽  
Ali Dadkhodaie ◽  
Rahim Mehrabi ◽  
Brian J. Steffenson

The wheat leaf rust fungus, Puccinia triticina, has widespread geographical distribution in Iran within the Fertile Crescent region of the Middle East where wheat was domesticated and P. triticina originated. Therefore, it is of great importance to identify the prevalence and distribution of P. triticina pathotypes in this area. From 2010 to 2017, 241 single-uredinium isolates of P. triticina were purified from 175 collections of P. triticina made from various hosts in 14 provinces of Iran, and they were tested on 20 Thatcher near-isogenic lines carrying single-leaf rust resistance genes. In total, 86 pathotypes were identified, of which the pathotypes FDTTQ, FDKPQ, FDKTQ, and FDTNQ were most prevalent. No virulence for Lr2a was detected, whereas virulence for Lr1 was found only on bread wheat in a few provinces in 2016. Only isolates from durum wheat and wild barley were virulent to Lr28. Although virulence for Lr9, Lr20, and Lr26 was observed in some years, the virulence frequency for these genes was lower than that of the other Lr genes. P. triticina collections from host plants with different ploidy levels or genetically dissimilar backgrounds were grouped individually according to genetic distance. Based on these results, collections from barley, durum wheat, oat, triticale, and wild barley were different from those of bread wheat.


2017 ◽  
Vol 107 (11) ◽  
pp. 1381-1387 ◽  
Author(s):  
Naeela Qureshi ◽  
Harbans Bariana ◽  
James A. Kolmer ◽  
Hanif Miah ◽  
Urmil Bansal

Leaf rust, caused by Puccinia triticina, is a constraint to durum wheat (Triticum turgidum subsp. durum) production, and landraces are reported to be an important source of resistance. Two Portuguese landraces (Aus26582 and Aus26579) showed resistance against durum-specific P. triticina races and were crossed with a susceptible landrace (Bansi) to develop recombinant inbred line (RIL) populations. Monogenic segregation for leaf rust resistance was observed among both RIL populations. The underlying locus, temporarily named LrAW2, was mapped to the short arm of chromosome 6B in the Aus26582/Bansi population and five DArTseq markers cosegregated with LrAW2. Simple sequence repeat markers sun683 and sun684, developed from the chromosome survey sequence (CSS) contig 6BS_2963854, identified through BlastN search of cosegregating DArTseq markers in the International Wheat Genome Sequencing Consortium database, cosegregated with LrAW2. Comparison of the CSS contig 6BS_2963854-based sequences amplified from parental genotypes led to the development of marker sunKASP_60, which also showed close linkage with LrAW2. Markers sun684 and sunKASP_60 showed close association with LrAW2 in both RIL populations. The amplification of LrAW2-specific products by linked markers in Aus26582, Aus26579, and Guayacan (Lr61) indicated that LrAW2 may be Lr61. The alternate amplicon or haplotype produced with LrAW2-linked markers in Australian durum cultivars demonstrated their effectiveness in marker-assisted selection.


Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 655-664 ◽  
Author(s):  
Li Huang ◽  
Steven A Brooks ◽  
Wanlong Li ◽  
John P Fellers ◽  
Harold N Trick ◽  
...  

Abstract We report the map-based cloning of the leaf rust resistance gene Lr21, previously mapped to a generich region at the distal end of chromosome arm 1DS of bread wheat (Triticum aestivum L.). Molecular cloning of Lr21 was facilitated by diploid/polyploid shuttle mapping strategy. Cloning of Lr21 was confirmed by genetic transformation and by a stably inherited resistance phenotype in transgenic plants. Lr21 spans 4318 bp and encodes a 1080-amino-acid protein containing a conserved nucleotide-binding site (NBS) domain, 13 imperfect leucine-rich repeats (LRRs), and a unique 151-amino-acid sequence missing from known NBS-LRR proteins at the N terminus. Fine-structure genetic analysis at the Lr21 locus detected a noncrossover (recombination without exchange of flanking markers) within a 1415-bp region resulting from either a gene conversion tract of at least 191 bp or a double crossover. The successful map-based cloning approach as demonstrated here now opens the door for cloning of many crop-specific agronomic traits located in the gene-rich regions of bread wheat.


Genome ◽  
2017 ◽  
Vol 60 (12) ◽  
pp. 1076-1085 ◽  
Author(s):  
M. Niranjana ◽  
Vinod ◽  
J.B. Sharma ◽  
Niharika Mallick ◽  
S.M.S. Tomar ◽  
...  

Leaf rust (Puccinia triticina) is a major biotic stress affecting wheat yields worldwide. Host-plant resistance is the best method for controlling leaf rust. Aegilops speltoides is a good source of resistance against wheat rusts. To date, five Lr genes, Lr28, Lr35, Lr36, Lr47, and Lr51, have been transferred from Ae. speltoides to bread wheat. In Selection2427, a bread wheat introgresed line with Ae. speltoides as the donor parent, a dominant gene for leaf rust resistance was mapped to the long arm of chromosome 3B (LrS2427). None of the Lr genes introgressed from Ae. speltoides have been mapped to chromosome 3B. Since none of the designated seedling leaf rust resistance genes have been located on chromosome 3B, LrS2427 seems to be a novel gene. Selection2427 showed a unique property typical of gametocidal genes, that when crossed to other bread wheat cultivars, the F1 showed partial pollen sterility and poor seed setting, whilst Selection2427 showed reasonable male and female fertility. Accidental co-transfer of gametocidal genes with LrS2427 may have occurred in Selection2427. Though LrS2427 did not show any segregation distortion and assorted independently of putative gametocidal gene(s), its utilization will be difficult due to the selfish behavior of gametocidal genes.


Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 469-473 ◽  
Author(s):  
S. A. Herrera-Foessel ◽  
R. P. Singh ◽  
J. Huerta-Espino ◽  
H. M. William ◽  
V. Garcia ◽  
...  

Leaf rust, caused by Puccinia triticina, is an important disease of durum wheat (Triticum turgidum subsp. durum) and only a few designated resistance genes are known to occur in this crop. A dominant leaf rust resistance gene in the Chilean durum cv. Llareta INIA was mapped to chromosome arm 7BL through bulked segregant analysis using the amplified fragment length polymorphism (AFLP) technique, and by mapping three polymorphic markers in the common wheat (T. aestivum) International Triticeae Mapping Initiative population. Several simple sequence repeat (SSR) markers, including Xgwm344-7B and Xgwm146-7B, were associated with the leaf rust resistance gene. Resistance response and chromosomal position indicated that this gene is likely to be Lr14a. The SSR markers Xgwm344-7B and Xgwm146-7B and one AFLP marker also differentiated common wheat cv. Thatcher from the near-isogenic line with Lr14a, as well as durum ‘Altar C84’ from durum wheat with Lr14a. This is the first report of the presence of Lr14a in durum wheat, although the gene originally was transferred from emmer wheat ‘Yaroslav’ to common wheat. Lr14a is also present in CIMMYT-derived durum ‘Somateria’ and effective against Mexican and other P. triticina races of durum origin. Lr14a should be deployed in combination with other effective leaf rust resistance genes to prolong its effectiveness in durum wheat.


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