INHERITANCE IN HEXAPLOID WHEAT OF LEAF RUST RESISTANCE AND OTHER CHARACTERS DERIVED FROM AEGILOPS SQUARROSA

1969 ◽  
Vol 11 (3) ◽  
pp. 639-647 ◽  
Author(s):  
E. R. Kerber ◽  
P. L. Dyck

The inheritance of seedling leaf rust resistance and several morphological characters derived from Aegilops squarrosa (2n = 14 = DD) was investigated in a synthetic hexaploid wheat. The hexaploid was obtained by combining the tetraploid component (2n = 28 = AABB) extracted from the common wheat cultivar Canthatch with Ae. squarrosa var. meyeri R.L. 5289.A major, partially dominant gene was identified that gives good resistance (type 0;1 reaction) to leaf rust races 1, 5, 9, 11, 15, 30, 58 and 126a. This gene was shown to be different from the resistance genes Lr1, Lr2, Lr3, Lr10, Lr16, Lr17 and Lr18. A minor second gene was also detected which gives resistance (type 2 reaction) to race 9 and slight resistance to some of the other races.Each of the characters purple coleoptile, non-waxy foliage, brown glumes, and non-free threshing (tenacious glumes) of the synthetic wheat was monogenically inherited. The gene for threshability may be different from other genetic systems known to affect this character. The gene for brown glumes was linked with the major gene for leaf rust resistance with a recombination value of 3.1 ± 1.1%. The genes for non-waxy foliage and non-free threshing were associated with an estimated linkage value of 15.1 ± 2.6%.The results effectively demonstrated the relative ease with which genetic variation may be incorporated into common hexaploid wheat from its ancestral diploid, Ae. squarrosa, by means of a synthetic hexaploid intermediary. The method avoids the difficulties and complications often encountered with the transfer of genes from more distantly related species which do not have a genome in common with T. aestivum.

1970 ◽  
Vol 12 (1) ◽  
pp. 175-180 ◽  
Author(s):  
P. L. Dyck ◽  
E. R. Kerber

The inheritance of adult-plant leaf rust resistance derived from Aegilops squarrosa was studied in a synthetic hexaploid wheat. The hexaploid was produced by combining the AABB component extracted from the common wheat cultivar Canthatch with Ae. squarrosa var. strangulata R.L. 5271 which has adult-plant resistance to several races of leaf rust. Resistance is conferred by a single, partially dominant gene that is inherited independently of Lr12 and L13, two previously identified genes for adult-plant leaf rust resistance. Although monogenic inheritance was observed, this gene must be influenced by the genetic background since its level of resistance was somewhat reduced during successive backcrosses to Thatcher.This new gene for adult-plant leaf rust resistance was linked with each of the genes for foliage waxiness and threshability with a recombination value of 15.6 ± 2.5% and 6.0 ± 1.5%, respectively. The genes for foliage waxiness and threshability were associated with an estimated linkage value of 17.4 ± 2.5%.


2019 ◽  
Author(s):  
Volker Mohler ◽  
Michael Schmolke ◽  
Friedrich J. Zeller ◽  
Sai L.K. Hsam

SummarySeedling resistance to leaf rust available in the synthetic hexaploid wheat line Syn137 was characterized by means of cytogenetic and linkage mapping. Monosomic analysis located a single dominant gene for leaf rust resistance on chromosome 5D. Molecular mapping not only confirmed this location but also positioned the gene to the distal part of the long arm of chromosome 5D. A test of allelism showed that the gene, tentatively named LrSyn137, is independent but closely linked to Lr1. It appears that Syn137 is occasionally heterogeneous for Lr1 since the analysis of the Lr1-specific marker RGA567-5 in the mapping population indicated the presence of Lr1. Syn137 represents another source of genetic variation that can be useful for the diversification of leaf rust resistance in wheat cultivars.


1974 ◽  
Vol 16 (1) ◽  
pp. 137-144 ◽  
Author(s):  
G. G. Rowland ◽  
E. R. Kerber

Telocentrics of hexaploid wheat, Triticum aestivum spp. vulgare cv. Chinese Spring, were used to establish the chromosome arm location and crossover distance from the centromere of genes controlling characters introduced into synthetic hexaploid wheat (2n = 42 = AABBDD) from Aegilops squarrosa (2n = 14 = DD). The chromosome arm location and the crossover distance from the centromere of each gene studied are as follows: synthetic hexaploid RL 5404 — brown glumes (Rg2), 1DL, 13.3 ± 3.3%; tenacious glumes (Tg), 2Dα, 39.4 ± 4.9%; inhibitor of waxy foliage (W21), 2Dα, 52.5 ± 5.0%; adult-plant leaf rust resistance (Lr22), 2Dα, 63.6 ± 4.8%; purple coleoptile (Rc3), 7DS, 10.3 ± 2.8%; synthetic hexaploid RL 5406 — Rg2, 1DL, 1.7 ± 1.0%; Tg, 2Dα, 42.9 ± 4.6%; W21, 2Dα, 58.9 ± 4.6%; Rc3, 7DS, 9.8 ± 2.8%. A gene for seedling leaf rust resistance (Lr21) found in RL 5406 is located on chromosome 1D.


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.


2011 ◽  
Vol 47 (No. 2) ◽  
pp. 45-57 ◽  
Author(s):  
N.A. Hovhannisyan ◽  
M.E. Dulloo ◽  
A.H. Yesayan ◽  
H. Knüpffer ◽  
A. Amri

Wild Triticum and Aegilops species are increasingly used in wheat breeding programmes around the world as donors of genes conferring resistance to biotic and abiotic stresses, as well as of genes that contribute to the improvement of grain quality. In the present study, thirty-nine accessions of diploid species with the A genome (Triticum boeoticum and T. urartu) were evaluated for the presence of the genes conferring resistance to powdery mildew (Blumeria graminis) and leaf rust (Puccinia recondita) using both inoculation tests and sequence tagged sites (STS) marker analyses in order to find correspondence between STS markers and resistance as a trait. The most resistant entries were T. boeoticum accessions. All the marked Lr and Pm resistance genes (Pm1, Pm2, Pm3, Lr10, Lr47, Lr25 and Lr28) were identified in the check T. aestivum cultivar Bezostaya 1. The resistance to powdery mildew in the material studied was conferred by the combination of the Pm1 gene with either Pm2 or Pm3. The Pm1 and Pm3 markers appeared to be suitable for tracking these powdery mildew resistance genes, while the Pm2 gene marker cannot be considered as usable in various genetically different wheat accessions. The presence of the genes Lr25, Lr28 and Lr47 seems to be particularly useful for obtaining leaf rust resistance in T. boeoticum and T. urartu species.  


1994 ◽  
Vol 74 (4) ◽  
pp. 671-673 ◽  
Author(s):  
P. L. Dyck

Accession 8404 of Triticum turgidum ssp. dicoccoides was shown to have excellent resistance to leaf rust. Genetic analysis of the F3 of 8404 and RL6089, a leaf rust susceptible durum, indicated that 8404 had three genes for leaf rust resistance. Two of these genes were transferred to hexaploid wheat (Thatcher) by a series of backcrosses. One of the genes transferred was the same as Lr33 (RL6057). The second gene, which gives a fleck reaction to avirulent P. recondita races, appears to be fully incorporated into the hexaploid where it segregated to fit a one-gene ratio. Backcross lines with this gene give excellent resistance to leaf rust, although race MBG is virulent to this gene. This may be a previously unidentified leaf rust resistance gene and should increase the genetic diversity available for wheat breeders. Key words:Triticum aestivum, wheat, Triticum turgidum ssp. dicoccoides, leaf rust resistance


Genome ◽  
1990 ◽  
Vol 33 (4) ◽  
pp. 530-537 ◽  
Author(s):  
E. R. Kerber ◽  
P. L. Dyck

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.


2014 ◽  
Vol 50 (No. 4) ◽  
pp. 262-267 ◽  
Author(s):  
J. Wang ◽  
L. Shi ◽  
L. Zhu ◽  
X. Li ◽  
D. Liu

The wheat (Triticum aestivum L.) line 5R618, bred at the China Agricultural University, is resistant in the seedling stage to the majority of the current Chinese pathotypes of wheat leaf rust (Puccinia triticina). To identify and map the leaf rust resistance gene in the 5R618 line, F<sub>2</sub> plants and F<sub>2:3</sub> families from a cross between 5R618 and Zhengzhou5389 (susceptible) were inoculated in the greenhouse with the Chinese P. triticina pathotype THJP. Results from the F<sub>2</sub> and F<sub>2:3</sub> populations indicate that a single dominant gene, temporarily designated&nbsp;Lr5R, conferred resistance. Using the molecular marker method, Lr5R was located on the 3DL chromosome. It was closely linked to the markers Xbarc71 and OPJ-09 with genetic distances of 0.9 cM and 1.0 cM, respectively. At present only one designated gene (Lr24) is located on the 3DL chromosome. The genetic distance between Lr5R&nbsp;and Lr24 confirms that Lr5R is a new leaf rust resistance gene.


2013 ◽  
Vol 39 (11) ◽  
pp. 1983
Author(s):  
Shu-Xiao HAN ◽  
Quan-Lan LIU ◽  
Jie DONG ◽  
Jian-Sheng CHEN ◽  
Ji-Chun TIAN

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