Mining synthetic hexaploids for multiple disease resistance to improve bread wheat

2008 ◽  
Vol 59 (5) ◽  
pp. 421 ◽  
Author(s):  
F. C. Ogbonnaya ◽  
M. Imtiaz ◽  
H. S. Bariana ◽  
M. McLean ◽  
M. M. Shankar ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Bread Wheat ◽  
Stripe Rust ◽  
Stem Rust ◽  
Wheat Yield ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Seedling Resistance

A collection of 253 synthetic hexaploid wheats (SHWs) produced from 192 Aegilops tauschii accessions and 39 elite durum varieties were studied to identify, characterise, and evaluate potentially untapped diversity of disease resistance in wheat. The diseases for which resistance was sought included cereal cyst nematode (CCN), root lesion nematode (RLN), Stagonospora nodorum blotch (SNB), Septoria tritici blotch (STB), and the 3 rusts, leaf rust, stem rust, and stripe rust, all important diseases of bread wheat worldwide, which can severely reduce wheat yield and quality. The SHWs exhibited a wide spectrum of resistance to the 8 pathogens. The frequency of disease-resistant SHWs ranged from 1% for one species of RLN (Pratylenchus neglectus), 3% and 10% for Septoria nodorum leaf and glume blotch, 10% for seedling resistance to yellow leaf spot, 16% for CCN, 21% for the second species of RLN (Pratylenchus thornei), 73% for Septoria tritici blotch, and 15%, 40%, and 24% for leaf rust, stem rust, and stripe rust, respectively. Five SHWs, Aus26860, Aus30258, Aus30294, Aus30301, and Aus30304, exhibited high levels of resistance to CCN, YLP, STB, LR, and SR, while 56 SHWs showed resistance to either 3 or 4 diseases. The genetics of resistance to CCN in some of the SHWs revealed that some of the accessions carry the same CCN gene(s) against pathotype Ha13, while others may carry different resistance gene(s). Additional studies were carried out to understand the relationship between the resistances identified in SHWs and the ones already present in common wheat, in particular the resistance genes Cre1 and Cre3 against CCN. The use of perfect markers associated with Cre1 and Cre3 suggested that some SHWs may carry a new CCN resistance gene(s), which could be deployed in breeding programs to increase the diversity of available resistance. The identification of SHWs with resistance to a range of diseases provides an opportunity to generate genetic knowledge and resistant germplasm to be used in future variety development.

Seedling resistances to rust diseases in international triticale germplasm

2010 ◽  
Vol 61 (12) ◽  
pp. 1036 ◽  
Author(s):  
J. Zhang ◽  
C. R. Wellings ◽  
R. A. McIntosh ◽  
R. F. Park
Keyword(s):  
Leaf Rust ◽  
Stripe Rust ◽  
Plant Resistance ◽  
Stem Rust ◽  
Rust Resistance ◽  
Adult Plant Resistance ◽  
Stem Rust Resistance ◽  
Adult Plant ◽  
Seedling Resistance ◽  
Rust Diseases

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.

Disease resistance in the genusAegilops L. — stem rust, leaf rust, stripe rust, and powdery mildew

1985 ◽  
Vol 33 (2) ◽  
pp. 133-153 ◽  
Author(s):  
Jan Valkoun ◽  
Karl Hammer ◽  
Dagmar Kučerová ◽  
Pavel Bartoš
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Leaf Rust ◽  
Stripe Rust ◽  
Stem Rust

GENETICS OF LEAF RUST REACTION IN THREE INTRODUCTIONS OF COMMON WHEAT

1977 ◽  
Vol 19 (4) ◽  
pp. 711-716 ◽  
Author(s):  
P. L. Dyck
Keyword(s):  
Triticum Aestivum ◽  
Disease Resistance ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Common Wheat ◽  
Infection Type ◽  
Triticum Aestivum L ◽  
Puccinia Recondita ◽  
Seedling Resistance

The genetics of seedling resistance to leaf rust (Puccinia recondita Rob. ex. Desm.) was investigated in what (Triticum aestivum L.) introductions PI 268454, PI 58548 and PI 268316, originally collected in Afghanistan, China and Iran, respectively. PI 268454 was heterogeneous for resistance. A selection (PI 268454a) has a gene that confers a 1+ reaction while a second selection (PI 268454b) probably has resistance gene Lr2b. PI 58548 has two genes for resistance, one giving a 1+ reaction and the second a 2+. These two genes interact to produce a; 1 reaction. PI 268316 has three interacting genes, one giving a 1+ reaction, the second a 2+ and a third resistance gene similar to LrB. The gene giving the 1+ reaction was common to all three introductions. PI 58548 and PI 268316 carry different genes for infection type 2+. Backcross lines of the single genes were produced. Implications to breeding for disease resistance of genes interacting to produce different phenotype are discussed.

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
Keyword(s):  
Durum Wheat ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Bread Wheat ◽  
Triticum Turgidum ◽  
Single Gene ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Seedling Resistance ◽  
Seedling Resistance Gene

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.

scholarly journals Genetic analysis of leaf rust resistance in three common wheat cultivars MP 3288, HI 784 and HI 1418 under field conditions

2019 ◽  
Vol 79 (01) ◽  
Author(s):  
T. L. Prakasha ◽  
S. Chand ◽  
A. N. Mishra ◽  
K. S. Solanki ◽  
J. B. Singh ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Bread Wheat ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
The Other ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
Seedling Resistance

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.

scholarly journals Resistance to Leaf Rust, Stripe Rust, and Stem Rust in Aegilops spp. in Israel

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 303-308 ◽  
Author(s):  
Y. Anikster ◽  
J. Manisterski ◽  
D. L. Long ◽  
K. J. Leonard
Keyword(s):  
Leaf Rust ◽  
Common Wheat ◽  
Stripe Rust ◽  
Stem Rust ◽  
Field Tests ◽  
Puccinia Triticina ◽  
Wheat Breeding ◽  
Wheat Leaf Rust ◽  
Seedling Resistance ◽  
Wheat Leaf

In all, 1,323 single plant accessions of Aegilops bicornis, A. kotschyi, A. longissima, A. ovata, A. searsii, A. sharonensis, A. speltoides, and A. variabilis collected from 18 regions in Israel and 2 adjacent regions in Lebanon and Egypt were evaluated for leaf rust (Puccinia triticina) and stripe rust (P. striiformis) resistance in field plots and for seedling resistance to leaf rust and stem rust (P. graminis f. sp. tritici) in greenhouse tests. Nearly all accessions of A. speltoides were highly resistant to leaf rust, stripe rust, and stem rust. A. longissima and A. ovata were highly resistant to stripe rust, whereas A. bicornis and A. kotschyi were highly susceptible. A. searsii was highly susceptible to stem rust, but 24 to 51% of accessions of A. bicornis, A. longissima, A. ovata, and A. variabilis were resistant to stem rust. Except for A. ovata and A. speltoides, more than 95% of the Aegilops accessions were susceptible to leaf rust caused by P. recondita alternating on Anchusa spp. Only Aegilops ovata was susceptible to P. recondita from Echium spp. A. bicornis, A. koschyi, and A. searsii were highly susceptible as seedlings to common wheat leaf rust caused by P. triticina. Most accessions of A. variabilis and about half of the accessions of A. longissima had good seedling resistance to P. triticina. Few accessions of A. ovata showed seedling resistance to the P. triticina population in Israel, but 30% were resistant to U.S. isolates. In field tests, A. bicornis showed high susceptibility to common wheat leaf rust, but more than 90% of the accessions of the other Aegilops spp. developed little or no leaf rust on adult plants. The Aegilops spp. in Israel and adjoining countries provide a rich and varied source of rust resistance for wheat breeding.

scholarly journals Map-Based Cloning of Leaf Rust Resistance Gene Lr21 From the Large and Polyploid Genome of Bread Wheat

Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 655-664 ◽  
Author(s):  
Li Huang ◽  
Steven A Brooks ◽  
Wanlong Li ◽  
John P Fellers ◽  
Harold N Trick ◽  
...  
Keyword(s):  
Amino Acid ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Bread Wheat ◽  
Rust Resistance ◽  
Agronomic Traits ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Rust Resistance Gene ◽  
Leaf Rust Resistance Gene

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.

THE INHERITANCE OF RESISTANCE IN RYE TO Puccinia recondita f. sp. secalis and f. sp. tritici

1984 ◽  
Vol 64 (3) ◽  
pp. 511-519 ◽  
Author(s):  
G. L. C. MUSA ◽  
P. L. DYCK ◽  
D. J. SAMBORSKI
Keyword(s):  
Disease Resistance ◽  
Leaf Rust ◽  
Secale Cereale ◽  
Single Gene ◽  
Inbred Lines ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Susceptible Parent ◽  
Seedling Resistance ◽  
Wheat Leaf

The inheritance of seedling resistance to isolate RLR 213/78 of rye leaf rust (Puccinia recondita f. sp. secalis) and race 30 of wheat leaf rust (P. recondita f. sp. tritici Rob.) was investigated in six inbred lines of rye (Secale cereale). Inbred line UM8116 was used as the susceptible parent in crosses. Inbred lines UM8003, UM8071 and UM8301 each have a single gene and UM8336 and UM8340 each have two genes for resistance to rye leaf rust. For resistance to wheat leaf rust UM8071 has a single gene, UM8003 and UM8340 each have two genes and UM8301 and UM8336 each have three genes. UM8295 is heterogeneous for reaction to both rusts. One of the genes in UM8340 may condition resistance to both rusts. The genes for resistance to RLR 213/78 appear to be independently inherited while some of the genes conferring resistance to race 30 may be identical or very closely linked. The potential of rye as a source of disease resistance for wheat and triticale improvement is discussed.Key words: Secale cereale, disease resistance, wheat leaf rust

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