Mapping of Adult Plant Leaf Rust Resistance in Aus27506 and Validation of Underlying Loci by In-Planta Fungal Biomass Accumulation

Among the rust diseases, leaf rust of wheat caused by Puccinia triticina, is the most prevalent worldwide and causes significant yield losses. This study aimed to determine the genomic location of loci that control adult plant resistance (APR) to leaf rust in the pre-Green Revolution landrace accession, Aus27506, from the “Watkins Collection”. An Aus27506/Aus27229-derived F7 recombinant inbred line (RIL) population was screened under field conditions across three cropping seasons and genotyped with the iSelect 90K Infinium SNP bead chip array. One quantitative trait loci (QTL) on each of the chromosomes 1BL, 2B and 2DL explained most of the leaf rust response variation in the RIL population, and these were named QLr.sun-1BL, QLr.sun-2B and QLr.sun-2DL, respectively. QLr.sun-1BL and QLr.sun-2DL were contributed by Aus27506. QLr.sun-1BL is likely Lr46, while QLr.sun-2DL appeared to be a new APR locus. The alternate parent, Aus27229, carried the putatively new APR locus QLr.sun-2B. The comparison of average severities among RILs carrying these QTL in different combinations indicated that QLr.sun-2B does not interact with either of the other two QTL; however, the combination of QLr.sun-1BL and QLr.sun-2DL reduced disease severity significantly. In planta fungal quantification assays validated these results. The RILs carrying QLr.sun-1BL and QLr.sun-2DL did not differ significantly from the parent Aus27506 in terms of resistance. Aus27506 can be used as a source of adult plant leaf rust resistance in breeding programs.

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Mapping of Adult Plant Leaf Rust Resistance in Aus27506 and Validation of Underlying Loci by In-Planta Fungal Biomass Accumulation

10.20944/preprints202004.0487.v1 ◽

2020 ◽

Author(s):

Pakeerathan Kandiah ◽

Mumta Chhetri ◽

Matthew Hayden ◽

Michael Ayliffe ◽

Harbans Bariana ◽

...

Keyword(s):

Leaf Rust ◽

Rust Resistance ◽

Green Revolution ◽

Puccinia Triticina ◽

Biomass Accumulation ◽

Leaf Rust Resistance ◽

Adult Plant ◽

In Planta ◽

Plant Leaf ◽

Ril Population

Among the rust diseases, leaf rust of wheat caused by Puccinia triticina, is the most prevalent worldwide and causes significant yield losses. This study aimed to determine the genomic location of loci that control adult plant resistance (APR) to leaf rust in the pre-Green Revolution landrace accession, Aus27506, from the ‘Watkins Collection’. An Aus27506/Aus27229-derived F7 recombinant inbred (RIL) population was screened under field conditions across three cropping seasons and genotyped with the iSelect 90K Infinium SNP bead chip array. One QTL on each of chromosomes 1BL, 2B and 2DL explained most of the leaf rust response variation in the RIL population and were named QLr.sun-1BL, QLr.sun-2B and QLr.sun-2DL, respectively. QLr.sun-1BL and QLr.sun-2DL were contributed by Aus27506. QLr.sun-1BL is likely Lr46, while QLr.sun-2DL appeared to be a new APR locus. The alternate parent, Aus27229, carried the putatively new APR locus QLr.sun-2B. Comparisons of average severities among RILs carrying these QTL in different combinations indicated that QLr.sun-2B does not interact with either of the other two QTL; however, the combination of QLr.sun-1BL and QLr.sun-2DL reduced disease severity significantly. In-planta fungal quantification assays validated these results. The RILs carrying QLr.sun-1BL and QLr.sun-2DL did not differ significantly from parent Aus27506 in resistance. Aus27506 can be used as a source of adult plant leaf rust resistance in breeding programs.

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Adult Plant Leaf Rust Resistance Derived from Toropi Wheat is Conditioned by Lr78 and Three Minor QTL

Phytopathology ◽

10.1094/phyto-07-17-0254-r ◽

2018 ◽

Vol 108 (2) ◽

pp. 246-253 ◽

Cited By ~ 13

Author(s):

J. A. Kolmer ◽

A. Bernardo ◽

G. Bai ◽

M. J. Hayden ◽

S. Chao

Keyword(s):

Leaf Rust ◽

Resistance Genes ◽

Rust Resistance ◽

Recombinant Inbred Lines ◽

Single Gene ◽

Puccinia Triticina ◽

Leaf Rust Resistance ◽

Adult Plant ◽

Field Plot ◽

Plant Leaf

Leaf rust caused by Puccinia triticina is an important disease of wheat in many regions worldwide. Durable or long-lasting leaf rust resistance has been difficult to achieve because populations of P. triticina are highly variable for virulence to race-specific resistance genes, and respond to selection by resistance genes in released wheat cultivars. The wheat cultivar Toropi, developed and grown in Brazil, was noted to have long-lasting leaf rust resistance that was effective only in adult plants. The objectives of this study were to determine the chromosome location of the leaf rust resistance genes derived from Toropi in two populations of recombinant inbred lines in a partial Thatcher wheat background. In the first population, a single gene with major effects on chromosome 5DS that mapped 2.2 centimorgans distal to IWA6289, strongly reduced leaf rust severity in all 3 years of field plot tests. This gene for adult plant leaf rust resistance was designated as Lr78. In the second population, quantitative trait loci (QTL) with small effects on chromosomes 1BL, 3BS, and 4BS were found. These QTL expressed inconsistently over 4 years of field plot tests. The adult plant leaf rust resistance derived from Toropi involved a complex combination of QTL with large and small effects.

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Adult Plant Leaf Rust Resistance Derived from the Soft Red Winter Wheat Cultivar ‘Caldwell’ Maps to Chromosome 3BS

Crop Science ◽

10.2135/cropsci2017.05.0272 ◽

2018 ◽

Vol 58 (1) ◽

pp. 152-158 ◽

Cited By ~ 13

Author(s):

J. A. Kolmer ◽

S. Chao ◽

G. Brown-Guedira ◽

U. Bansal ◽

H. Bariana

Keyword(s):

Winter Wheat ◽

Leaf Rust ◽

Rust Resistance ◽

Wheat Cultivar ◽

Leaf Rust Resistance ◽

Adult Plant ◽

Winter Wheat Cultivar ◽

Plant Leaf ◽

Soft Red Winter Wheat ◽

Red Winter Wheat

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Genetic Analysis of Leaf Rust Resistance in Six Durum Wheat Genotypes

Phytopathology ◽

10.1094/phyto-03-14-0065-r ◽

2014 ◽

Vol 104 (12) ◽

pp. 1322-1328 ◽

Cited By ~ 8

Author(s):

Alexander Loladze ◽

Dhouha Kthiri ◽

Curtis Pozniak ◽

Karim Ammar

Keyword(s):

Durum Wheat ◽

Leaf Rust ◽

Resistance Genes ◽

Rust Resistance ◽

Durable Resistance ◽

Puccinia Triticina ◽

Leaf Rust Resistance ◽

Adult Plant ◽

Seedling Resistance ◽

Allelism Tests

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.

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Transfer to hexaploid wheat of linked genes for adult-plant leaf rust and seedling stem rust resistance from an amphiploid of Aegilops speltoides × Triticum monococcum

Genome ◽

10.1139/g90-079 ◽

1990 ◽

Vol 33 (4) ◽

pp. 530-537 ◽

Cited By ~ 70

Author(s):

E. R. Kerber ◽

P. L. Dyck

Keyword(s):

Leaf Rust ◽

Resistance Genes ◽

Stem Rust ◽

Rust Resistance ◽

Dominant Gene ◽

Leaf Rust Resistance ◽

Stem Rust Resistance ◽

Adult Plant ◽

Aegilops Speltoides ◽

Plant Leaf

A partially dominant gene for adult-plant leaf rust resistance together with a linked, partially dominant gene for stem rust resistance were transferred to the hexaploid wheat cultivar 'Marquis' from an amphiploid of Aegilops speltoides × Triticum monococcum by direct crossing and backcrossing. Pathological evidence indicated that the alien resistance genes were derived from Ae. speltoides. Differential transmission of the resistance genes through the male gametes occurred in hexaploid hybrids involving the resistant 'Marquis' stock and resulted in distorted segregation ratios. In heterozygotes, pairing between the chromosome arm with the alien segment and the corresponding arm of the normal wheat chromosome was greatly reduced. The apparent close linkage between the two resistance genes, 3 ± 1.07 crossover units, was misleading because of this decrease in pairing in the presence of the 5B diploidizing mechanism. The newly identified gene for adult-plant leaf rust resistance, located on chromosome 2B, is different from adult-plant resistance genes Lr12, Lr13, and Lr22 and from that in the hexaploid accession PI250413; it has been designated Lr35. It is not known whether the newly transferred gene for stem rust resistance differs from Sr32, also derived from Ae. speltoides and located on chromosomes 2B.Key words: hexaploid, Triticum, Aegilops, aneuploid, Puccinia graminis, Puccinia recondita.

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