Molecular Characterization of Bunt Resistance in Romanian Wheat Line F00628G34-M, Selected From a Triticale (<em>Triticosecale</em>) X Winter Bread Wheat (<em>Triticumaestivum</em>) Cross</em>

Research Article

Austin J Plant Biol. 2015; 1(2): 1008.

Molecular Characterization of Bunt Resistance in Romanian Wheat Line F00628G34-M, Selected From a Triticale (Triticosecale) X Winter Bread Wheat (Triticumaestivum) Cross

Ciuca M*, Cristina D and Turcu AG

Department of National Agricultural Research, University of Development Fundulea, Europe

*Corresponding author: Matilda Ciuca, Department of National Agricultural Research, University of Development Fundulea, 915200, Calarasi, ROMANIA, Europe

Received: August 14, 2015; Accepted: November 23, 2015; Published: November 27, 2015


Bunts are diseases produced by Tilletiacaries, T. laevis, T. controversa and T. secalis with severe effects on wheat yield and quality. Their importance has increased, especially in organic agriculture, where chemical treatments are forbidden. Rye is highly resistant to Tilletia sp. Breeders at NARDI Fundulea obtained a bunt resistant line F000628G34-M derived from a Triticale/2* wheat cross. Sixty eight randomly extracted F4 lines from a cross between F000628G34-M and susceptible wheat cultivarLiterawere phenotyped (using local populations of Tilletia sp.) and genotyped with 20 specific markers for 1 RS and 15 SSR markers located on 1AS. Chi square test showed significant deviation (P < 5%) from the expected Mendelian monogenic segregation, suggesting that the resistance gene is recessive or partially dominant and/or the resistance is affected by suppressing factors from wheat genome. Molecular markers assay proved a significant association of the bunt resistance inherited from the F00628G34-M line, with the 1A/1R translocation, suggesting that the bunt resistance gene originated from rye could be locatedin the region homeologous with the Glu-A3 locus and close to Xgwm1223 microsatellite locus. To our knowledge, this is the first time when it is proven that a bunt resistance gene is associated with the rye chromatin transfer to wheat.

Keywords: Wheat; Rye; Triticale; Bunt; Molecular markers; Tilletia sp


Agriculture in Europe has been moving toward organic farming and with “low-inputs”, including reduced chemicals use. Reduction or lack of chemical seed treatments have lead to resurgence of many seed-borne diseases including bunts, which were previously controlled with chemicals [1]. In Romania, if untreated seeds are used, the incidence of bunt can reach up to 70-80% and the yield losses can reach up to 40% [2].

Wheat bunts are produced by Tilletia caries (DC) Tul, T. laevis (Wallr) Liro. (Common bunt) and T. controversa (dwarf bunt), but T. secalis (on rye) can also affect wheat. Although chemical treatments have been successfully used to control bunt, genetic resistance is the most economical and ecological way of control, and is the only acceptable approach in organic agriculture. This is why bunt resistance has become an important objective in wheat breeding. At present, have been identified more than 15 resistant genes to common bunt (Bt1 to Bt15) and in addition, the gene Bt-Z in Agropyroninter medium, the gene Bt-P in wheat variety PI 173438, a new gene in Blizzard and also, a QTL on 7B chromosome in McKenzie cv designated [3-6]. The efficiency of resistance genes is different, but not very different from one area to another. In Romania the following genes have been identified with a good efficiency: Bt5, Bt8, Bt10, Bt11, Bt12, Bt13 [7].

Rye (Secalecereale L.) has already provided genes that proved useful in wheat breeding [8,9] and many cultivars that enjoyed a great success over time are carriers of translocations from rye, especially of some translocations in which the short arm of 1R chromosome is involved There are still many genes of interest for wheat improvement, not yet transferred, that are available in the rye genome, and that includes bunt resistance genes.

Phenotype observations conducted in the Czech Republic on 17 triticale cultivars showed presence of T. caries pathogen in a very low percent (2.4%) only on one triticale cultivar (Triamant) [10]. This result suggested that, due to the presence of rye chromatin, triticales are very resistant to common bunt attack. However, both rye and triticale were attacked by T. controversa (dwarf bunt). Similar results were reported by other researchers [4].

Triticale can be successfully used as a bridge for transferring useful rye genes to wheat [9]. The line F00628G34-M, created at NARDI Fundulea by crosses between triticale (Triticosecale) and wheat (Triticumaestivum), showed good resistance to bunt in artificial infections, both in tests from Romania, done at Fundulea [7] and Simnic [11] and in most locations of international tests from the European project “Tilletia Ring Test”. In the frame of this project, the F00628G34-M line was affected by Tilletia spp. at different levels, but considerably less than the susceptible entries (Austria -11.5%, Germany -15.5%, Croatia -race T7- 7.4%; race T9- 4.2%; race T17- 9.3%; race T02 – 4.7%) [12]. This line was previously characterized as carrying rye chromatin as a 1RS:1AL translocation, using hybridization techniques (GISH and FISH) at Research Institute of the Hungarian Academy of Sciences, Martonvásár, Hungary (Marta Molnar-Lang’s Department) by Constantina Banica (personal communication).

Marker Assisted Selection (MAS) has proved to be a very efficient method for increasing genetic progress and efficiency of breeding programs [13]. Starting from the necessity to obtain bunt resistant cultivars, taking into account the complexity of wheat genome, the difficulties of testing and selection of bunt resistant genotypes and the utility of molecular markers, this work proposes to look at the wheat genome with the help of molecular markers and to determine if the resistance to bunt in F000628G34-M line is associated with rye chromatin.

Biological material

The study was done on 68 F4linesrandomly extracted from the cross of the cultivarLitera, as susceptible parent, with the line F00628G34-M (Triticale/2* Wheat), as resistant parent.



The teliospores were mixed with seed in a paper envelope, next was shaken by hand until the seed was evenly and visibly darkened with teliospores (performed under the guidance of Dr. Mariana Ittu).

Field tests

Inoculated seeds were planted on one meter long rows, using as susceptible cultivars Dropia and Literal. At maturity, the lines were classified in bunted and non-bunted (0 % common bunt).Infected spikes (where at least one grain was replaced by bunt balls) were counted and expressed as percentage from total number of spikes.

DNA isolation was made from leaves, using CTAB method [14]. PCR- All amplification reactions were carried out in a 25μl volume. We used 20 markers specific for rye and for the 1R short arm chromosome [15-21] and 15 SSR markers localized on the 1AS chromosome [22]. The sequences of REMS markers were kindly offered by Dr. Victor Korzun -KWS LOCHOW, Germany, and for marker Xgwm752 the sequence was obtained by MTA (Material Transfer Agreement) from Dr. Marion Roder. For the marker Xgwm1223 the sequence was obtained by MTA-from “TraitGenetics” company, Germany -Dr. Martin Ganal (Table 1). The PCR products were separated on 1.2-1.5-2-2.5% agarose for routine use, in 0.5X TBE buffer, stained with ethidium bromide and photographed under ultraviolet light with VilberLourmat system.