Resistance In Triticale Research Articles

Pyramiding wheat pre-harvest sprouting resistance genes in triticale breeding

Pre-harvest sprouting (PHS) is an important problem in cereal production reducing yield and grain quality. After decades of improvement, triticale remains particularly susceptible to PHS but no resistance genes or QTLs were identified so far in this species. As wheat shares the A and B genomes with triticale, wheat PHS resistance genes can be introgressed into triticale genome by recombination after interspecific crosses. In this project, three PHS resistance genes have been transferred from wheat to triticale by marker-assisted interspecific crosses, followed by four backcrosses. The gene TaPHS1 from the 3AS chromosome of cultivar Zenkoujikomugi (Zen) and the TaMKK3 and TaQsd1, respectively located on the 4AL and 5BL chromosomes derived both from cultivar Aus1408, were pyramided in the triticale cultivar Cosinus. Only the TaPHS1 gene increases consistently the PHS resistance in triticale. The lack of efficacy of the other two genes, especially TaQsd1, could be the result of an imperfect linkage between the marker and the gene of interest. The introduction of PHS resistance genes did not alter agronomic nor disease resistance performances of triticale. This approach leads to two new, agronomically performant and PHS-resistant triticale cultivars. Today, two breeding triticale lines are ready to enter the official registration process.

Mapping of QTL and candidate genes associated with powdery mildew resistance in triticale (× Triticosecale Wittm.)

Mapping of QTL and candidate genes associated with powdery mildew resistance in triticale (× Triticosecale Wittm.)

Wheat dwarf genes Rht12 and Rht‐B1b affected the performance of agronomic traits in hexaploid triticale

AbstractAs a new synthetic species, triticale has been widely used for food and feed. Lodging is a severe problem in triticale production, and it is unknown whether wheat height‐reducing genes can improve lodging resistance in triticale. In this study, the wheat‐dwarfing genes Rht12 and Rht‐B1b were introgressed into hexaploid triticale (AABBRR) lines to understand their effect on plant height. The results showed that Rht12 and Rht‐B1b reduced the plant height of triticale plants by 37.7 and 29.9%, respectively. Rht12 and Rht‐B1b both had significant effects on the basal internode's length, diameter, and thickness, which may greatly improve lodging resistance. Additionally, the net photosynthetic rate was increased by 28.7% in Rht12 dwarf lines. However, Rht12 had a significant and negative effect on thousand‐kernel weight (14.5%) and yield per plant (20.6%). On the other hand, Rht‐B1b reduced the number of tillers by 19.6% and yield per plant by 18.1% with no negative effect on the harvest index. Furthermore, Rht12 and Rht‐B1b decreased grain plumpness but improved several grain quality traits. Conclusively, Rht12 and Rht‐B1b improved lodging resistance but had some negative effects on yield components, which need careful consideration in triticale breeding.

Triticale Improvement: Mining of Genes Related to Yellow Rust Resistance in Triticale Based on Transcriptome Sequencing.

Yellow (stripe) rust caused by Puccinia striiformis f. sp. tritici (Pst) is a major destructive fungal disease of small grain cereals, leading to large yield losses. The breeding of resistant varieties is an effective, sustainable way to control yellow rust. Elucidation of resistance mechanisms against yellow rust and identification of candidate genes associated with rust resistance are thus crucial. In this study, seedlings of two Triticosecale Wittmack cultivars, highly resistant Gannong No. 2 and susceptible Shida No. 1, were inoculated with Pst race CYR34. Transcriptome sequencing (RNA-seq) was then used to investigate their transcriptional responses against pathogen infection before and after the appearance of symptoms—10 and 20 days after inoculation, respectively. According to the RNA-seq data, the number of upregulated and downregulated differentially expressed genes (DEGs) in the resistant cultivar was greater than in the susceptible cultivar. A total of 2,560 DEGs commonly expressed in the two cultivars on two sampling dates were subjected to pathway analysis, which revealed that most DEGs were closely associated with defense and metabolic activities. Transcription factor enrichment analysis indicated that the expressions of NAC, WRKY, and FAR1 families were also significantly changed. Further in-depth analysis of resistance genes revealed that almost all serine/threonine-protein kinases were upregulated in the resistant cultivar. Other genes related to disease resistance, such as those encoding disease-resistance- and pathogenesis-related proteins were differentially regulated in the two cultivars. Our findings can serve as a resource for gene discovery and facilitate elucidation of the complex defense mechanisms involved in triticale resistance to Pst.

Genetic mapping of adult-plant resistance genes to powdery mildew in triticale

Triticale is a cereal of high economic importance; however, along with the increase in the area of this cereal, it is more often infected by the fungal pathogen Blumeria graminis, which causes powdery mildew. The rapid development of molecular biology techniques, in particular methods based on molecular markers may be an important tool used in modern plant breeding. Development of genetic maps, location of the QTLs defining the region of the genome associated with resistance and selection of markers linked to particular trait can be used to select resistant genotypes as well as to pyramidize several resistance genes in one variety. In this paper, we present a new, high-density genetic map of triticale doubled haploids (DH) population “Grenado” × “Zorro” composed of DArT, silicoDArT, and SNP markers. Composite interval mapping method was used to detect eight QTL regions associated with the area under disease progress curve (AUDPC) and 15 regions with the average value of powdery mildew infection (avPM) based on observation conducted in 3-year period in three different locations across the Poland. Two regions on rye chromosome 4R, and single loci on 5R and 6R were reported for the first time as regions associated with powdery mildew resistance. Among all QTLs, 14 candidate genes were identified coded cyclin-dependent kinase, serine/threonine-protein kinase-like protein as well as AMEIOTIC 1 homolog DYAD-like protein, DETOXIFICATION 16-like protein, and putative disease resistance protein RGA3. Three of identified candidate genes were found among newly described QTL regions associated with powdery mildew resistance in triticale.

ВЫЯВЛЕНИЕ ИСТОЧНИКОВ УСТОЙЧИВОСТИ К СЕПТОРИОЗУ У ГЕНОТИПОВ ОЗИМЫХ ТРИТИКАЛЕ В ЕСТЕСТВЕННЫХ ПОЛЕВЫХ УСЛОВИЯХ РЕСПУБЛИКИ МОЛДОВЫ

Presented are the results of studying the inheritance of the phenotypic reaction in reciprocal F 1 and F 2 winter triticale hybrids (x Triticosecale Wittm.) on a natural infectious background for septoria in climatic conditions of the Republic of Moldova are presented. The aim of this work was to identify sources of resistance among the genotypes of local triticale that are well adapted to septoria and study of the genetic control of the trait. The reaction of reciprocal F 1 and F 2 hybrids on susceptibility of septoria varied in the range of 0.1-3.1 points and 0-2.8 points, respectively. It has been established that the resistance of triticale to Septoria tritici can be both dominant and recessive, depending on the response of the parental genotypes and the direction of the crossing. The overdominance of S. tritici resistance was manifested in F 1 hybrids from reciprocal crossing of resistant genotypes (Podoima/Talovscaia 12 and Ingen 40). In the less favorable climatic conditions for the development of the disease (2017), F 2 hybrids obtained from crosses of the Podoima /Talovscaia 12, Ingen 40 and Ingen 93 genotypes manifested tolerance. A significant positive correlation (r = 0.52, p 2 hybrids. When creating varieties resistant to septoria and winter triticale lines, it is recommended to use adapted and less affected against the natural infectious background resistance donors Ingen 40 and Podoima /Talovscaia 12.

Genome-wide association study for an efficient selection of Fusarium head blight resistance in winter triticale

Fusarium head blight (FHB) is one of the most serious diseases in small-grain cereals including triticale (× Triticosecale Wittmack). The disease reduces yield and accumulates mycotoxins which are harmful to human and animal health. Triticale grain is almost exclusively used on-farm in feed formulations for swine and other animals, and swine is the most susceptible farm animal to Fusarium mycotoxins. In order to evaluate the potential of genomics-assisted breeding to FHB, we performed the first genome-wide association study for FHB resistance in triticale. QTL for FHB resistance were identified on chromosomes 2A, 2B, 5B and 3R with an explained genotypic variance ranging from 0.28 to 30.23% and a total explained genetic variance of 56.64%. A QTL on chromosome 3R that explained 15.38% of the genotypic variance was identified for the first time. Association mapping was complemented by genome-wide prediction, which yielded a high prediction accuracy of 0.78 for FHB resistance when weighted genomic selection was performed. Collectively our findings highlight the potential of genomics-assisted approaches to improve Fusarium resistance in triticale in early generations.

Prediction of hybrid performance for Fusarium head blight resistance in triticale (×Triticosecale Wittmack)

Like other small grain cereals, triticale (×Triticosecale Wittmack) is also affected by Fusarium head blight (FHB) which is a serious plant disease leading to yield losses and to a contamination of feed and food by harmful mycotoxins. Use of resistant varieties is the most effective way to manage FHB infections. More recently, commercial hybrid breeding in autogamous cereals has received increased interest. Therefore, we built a bridge between hybrid and resistance breeding and conducted a multi-environmental field trial using deliberate inoculation with Fusarium culmorum to: (i) evaluate different hybrid prediction approaches based on phenotypic and/or genomic data; (ii) compare the effect of cytoplasmic male sterility (CMS) inducing cytoplasm and normal (N) cytoplasm on FHB resistance. We evaluated 226 single cross hybrids, their paternal and maternal lines in both CMS- and N-cytoplasm. Our analysis revealed a large genetic variation for FHB resistance. Single cross hybrids tended to be more resistant than their parental lines. We observed a close association between N-lines and CMS-lines for FHB resistance. We found a predominance of σGCA2 over σSCA2 for FHB resistance. Correlation between the sum of general combining ability (GCA) effects and hybrid performance was high for FHB resistance. Mid-parent performance served as a moderate indicator for FHB resistance of single crosses. Best linear unbiased prediction of hybrid performance based on relatedness between tested and untested genotypes estimated by marker data showed great potential for hybrid prediction when no reliable per se information or GCA estimates are available.

Genetic architecture of fusarium head blight resistance in four winter triticale populations.

Fusarium head blight (FHB) is a devastating disease that causes significant reductions in yield and quality in wheat, rye, and triticale. In triticale, knowledge of the genetic architecture of FHB resistance is missing but essential due to modern breeding requirements. In our study, four doubled-haploid triticale populations (N=120 to 200) were evaluated for resistance to FHB caused by artificial inoculation with Fusarium culmorum in four environments. DArT markers were used to genotype triticale populations. Seventeen quantitative trait loci (QTL) for FHB resistance were detected across all populations; six of them were derived from rye genome and located on chromosomes 4R, 5R, and 7R, which are here reported for the first time. The total cross-validated ratio of the explained phenotypic variance for all detected QTL in each population was 41 to 68%. In all, 17 QTL for plant height and 18 QTL for heading stage were also detected across all populations; 3 and 5 of them, respectively, were overlapping with QTL for FHB. In conclusion, FHB resistance in triticale is caused by a multitude of QTL, and pyramiding them contributes to higher resistance.

Photosynthesis-dependent physiological and genetic crosstalk between cold acclimation and cold-induced resistance to fungal pathogens in triticale (Triticosecale Wittm.)

The breeding for resistance against fungal pathogens in winter triticale (Triticosecale Wittm.) continues to be hindered by a complexity of the resistance mechanisms, strong interaction with environmental conditions, and dependence on the plant genotype. We showed, that temperature below 4°C induced the plant genotype-dependent resistance against the fungal pathogen Microdochium nivale. The mechanism involved, at least, the adjustment of the reactions in the PSII proximity and photoprotection, followed by an improvement of the growth and development. The genotypes capable to develop the cold-induced resistance, showed a higher maximum quantum yield of PSII and a more efficient integration of the primary photochemistry of light reactions with the dark reactions. Moreover, induction of the photoprotective mechanism, involving at least the peroxidases scavenging hydrogen peroxide, was observed for such genotypes. Adjustment of the photosynthesis and stress acclimation has enabled fast plant growth and avoidance of the developmental stages sensitive to fungal infection. The same mechanisms allowed the quick regrow of plants during the post-disease period. In contrast, genotypes that were unable to develop resistance despite cold hardening had less flexible balancing of the photoprotection and photoinhibition processes. Traits related to: photosynthesis-dependent cold-acclimation and cold-induced resistance; biomass accumulation and growth; as well as protection system involving peroxidases; were integrated also at a genetic level. Analysing 95 lines of the mapping population SaKa3006×Modus we determined region on chromosomes 5B and 7R shared within all tested traits. Moreover, similar expression pattern of a set of the genes related to PSII was determined with the metaanalysis of the multiple microarray experiments. Comparable results for peroxidases, involving APXs and GPXs and followed by PRXs, indicated a similar function during cold acclimation and defense responses. These data provide a new insight into the cross talk between cold acclimation and cold-induced resistance in triticale, indicating a key role of photosynthesis-related processes.

The importance of non‐penetrated papillae formation in the resistance response of triticale to powdery mildew (Blumeria graminis)

Triticale is the intergeneric hybrid between wheat and rye. With the expansion of the triticale growing area, powdery mildew has emerged and become a significant disease on this new host. Recent research demonstrated that this ‘new’ powdery mildew on triticale has emerged through a host range expansion of powdery mildew of wheat. Moreover, isolates sampled from triticale still infect their previous host, wheat, but isolates sampled from wheat hardly infect triticale. Race‐specific and adult‐plant resistance have been identified in triticale cultivars. The main objective of this study was to characterize the cellular basis of powdery mildew resistance in triticale. Commonalities with resistance responses in other cereals such as wheat, barley and oat are discussed. A detailed comparative histological study of various resistance responses during cross‐inoculation of either virulent or avirulent wheat and triticale isolates on both hosts was carried out. The present data provide evidence that for incompatible interactions, the formation of non‐penetrated papillae is the predominant resistance response, while the hypersensitive response (HR) acts as a second line of defence, to cut the fungus off from nutrients, if penetration resistance fails. It is not clear yet what causes the slower growth and reduced colony size of triticale isolates when inoculated on wheat. Possibly, post‐penetration resistance mechanisms, other than HR, are switched on during these (semi‐) compatible interactions. Molecular studies on gene expression and gene function of defence‐related genes might reveal further insights into the genetic basis of these resistance responses.

Evaluation of Resistance to Powdery Mildew in Triticale Seedlings and Adult Plants.

Triticale (×Triticosecale) is the intergeneric hybrid between the female parent wheat and the male parent rye. With the expansion of the triticale growing area, powdery mildew emerged on this new host and has become a significant disease on triticale. Recent research demonstrated that this "new" powdery mildew on triticale has emerged through a host range expansion of powdery mildew of wheat. Moreover, this expansion occurred recently and multiple times at different locations in Europe. An effective and environmentally sensitive approach to controlling powdery mildew involves breeding crop plants for resistance. The main goal of this study was to identify the presence of powdery mildew resistance in commercial triticale cultivars. First, the avirulence (AVR) genes and gene complexity carried by this new powdery mildew population on triticale were characterized. Virulence was identified for all the resistance genes evaluated in the present study, and virulence frequencies higher than 50% were recorded on the genes Pm3f, Pm5b, Pm6, Pm7, Pm8, and Pm17. Using molecular markers, the presence of resistance genes Pm3f and Pm17 was identified in certain triticale cultivars. The triticale cultivars were also evaluated for the presence of quantitative resistance at adult plant growth stages in a 2-year field experiment. Despite the high disease pressure, cultivars highly resistant at the adult-plant growth stages were identified. Because 'Grenado' also showed effective race-specific resistance, this cultivar could be of high value for breeding for durable resistance to powdery mildew. Altogether, this study reveals valuable information on the presence of powdery mildew resistance in commercial triticale cultivars, which can be used in breeding programs in triticale. Additionally, this study underscores the need to broaden the base of powdery mildew resistance in triticale through introgression and deployment of new sources of mildew resistance, including quantitative resistance.

The association between the allelic state of <i>Vp</i>-1<i>B</i> and pre-harvest sprouting tolerance in red-seeded hexaploid triticale

The core collection of red-seeded winter hexaploid triticale with different pre-harvest sprouting (PHS) resistance has been evaluated for the allelic structure of the gene VIVIPAROUS-1B (Vp-1B) with STS molecular marker. The discovered structure of the collection was as follows: 50.0% and 41.7% of the collection carries Vp-1Bа and Vp-1Bc alleles, respectively, while 8,3% possesses both of them. As a result of the seed color estimation, the collection has been divided into two groups: with dark red seeds and light red seeds. The allele Vp-1Bc has appeared to be associated with PHS resistance while Vp-1Ba with PHS susceptibility in the triticale accessions with light red seeds only. The influence of the seed color and allelic state of Vp-1B on PHS resistance in triticale is discussed.

Cold-hardening of winter triticale (x Triticosecale Wittm.) results in increased resistance to pink snow mould Microdochium nivale (Fr., Samuels & Hallett) and genotype-dependent chlorophyll fluorescence modulations

The resistance of triticale (x Triticosecale Wittm.) to infection of snow mould Microdochium nivale (Fr., Samuels & Hallett) was examined under different temperature pre-treatment regimes. The results of laboratory “cold chamber” resistance tests correlated with the breeders’ report from field experiments. Studied genotypes differed substantially in their resistance to infection. Two cultivars: ‘Magnat’ (susceptible) and ‘Hewo’ (relatively resistant) were further studied as a plant model to test the role of pre-hardening and cold-hardening induction of resistance expression. Both model cultivars were susceptible to M. nivale infection without cold pre-treatment and gained genotype-depended level of resistance after 4 weeks treatment at 4°C, moreover the resistance grew gradually. Simultaneously to the resistance tests, the measurements of chlorophyll fluorescence parameters were taken. The results showed that higher vitality index Rfd of cold-hardened triticale seedlings correlated with increased pink snow mould resistance while differences in other parameters of fluorescence were not distinctly significant. Establishment of Rfd in 4 weeks hardened triticale seedlings could be used for a large scale screening of breeding material in order to select potentially resistant genotypes. Such analyses have not been reported for triticale before.

Means and variances for Fusarium head blight resistance of F2-derived bulks from winter triticale and winter wheat crosses

Fusarium head blight (FHB), caused by Fusarium graminearum and Fusarium culmorum, is a devastating disease in cereals. This study was undertaken to estimate progeny means and variances in each of five winter triticale and winter wheat crosses using unselected F2−derived lines in F4 or F5 generation bulked at harvest of the previous generation. Fifty (triticale) and 95 (wheat) progeny per cross were inoculated in two (triticale) or three (wheat) field environments. FHB rating was assessed on a whole-plot basis. Mean disease severities of the parents ranged from 2.3 to 6.4 in triticale and from 3.1 to 6.5 in wheat on a 1-to-9 scale (1 = symptomless, 9 = 100% infected). The midparent values generally resembled the means of their derived progeny. Significant (P < 0.01) genotypic variance was detected within each cross, but genotype × environment interaction and error variances were also high for both crops. Medium to high entry-mean heritabilities (0.6–0.8) underline the feasibility of selecting F2-derived bulks on a plot basis in several environments. Phenotypic correlation of FHB resistance between generation F2:4 and F2:5 was r = 0.87 (P < 0.01) tested across 150 wheat bulks at two locations. Our estimates of selection gain are encouraging for breeders to improve FHB resistance in triticale and wheat by recurrent selection within adapted materials.

Inheritance of wheat stem rust resistance in triticale

AbstractGenetic studies were conducted on nine triticale cultivars and lines lo determine the presence and identity of stem rust resistance genes. The lines were intercrossed and their F2 and F3 generations were tested with selected pathotypes of Puccinia graminis tritici. Segregation in seedling tesis showed the presence of two new genes SrLal and SrLa2 in ‘Lasko’, SrBj anil SrJ in ‘Bejon’. SrVen in ‘Currency’, SrBj in ‘Abacus’ and ‘RM4’ and SrNin in ‘Tahara’, ‘Maidan’ and ‘Madonna’ SrBj, SrNin, SrLal and SrLa2 were genetically independent and each conferred resistance to the currently important Australian P. graminis tritici pt 34‐2.12.13, whereas SrJ and SrVen conferred moderately susceptible reactions to the same pathotype. SrVen segregated independently of SrBj, but the relationship of SrVen with the other genes was noi determined. The typical low infection types conferred by SrBj and SrJ were best expressed at temperatures above 21 C, Prolamine separations nsinj; sodium dodecyl sulphate‐polyacrylamide gel elcclrophoresis confirmed that SiNin and SrBj were located in chromosome 2R. The gene SrLal behaved as a third allele at or near the Sr27, SrSatu locus in chromosome 3R, The present work demonstrated that chromosomes 2R and 3R are important bearers of genes Tor stem rust resistance in hexaploid iriticale.

Genetic and Cytogenetic Analyses of Russian Wheat Aphid Resistance in Triticale × Wheat Hybrids and Progenies

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is a serious pest in wheat (Triticum aestivum L.). Four Russian triticale (X Triticosecale Wittmack) lines, PI 386148, PI 386149, PI 386150, and PI 386156, have been the most resistant triticales to the RWA in several screening tests. Resistance is controlled by a single dominant gene at a common locus in the three triticale lines PI 386148, PI 386149, and PI 386156. However, expression of these resistance genes in a wheat background and the inheritance of resistance in PI 386150 have not been determined. The objectives of this study were (i) assess the transmission and the expression of RWA resistance in triticale × wheat hybrids, (ii) to determine the inheritance of resistance in PI 386150, and (iii) to identify the rye chromosome(s) from Secale montanum Guss. associated with RWA resistance. Advanced generations from crosses between PI 386148 triticale × ‘Lamar’ wheat and P1386150 triticale × Lamar were produced and the progenies screened to determine their reaction to the RWA. All F1 plants derived from both crosses were resistant indicating that resistance is dominant in both triticale lines. C‐banding and in situ hybridization with the pSc119.1 probe, a rye‐specific DNA probe, showed that chromosome 4Rmon was associated with resistance in PI 386150. The results of this study should facilitate the transfer of the resistance gene(s) from these triticale lines into wheat.

Genetic variation for head blight resistance in triticale caused by Fusarium graminearum isolates of different deoxynivalenol production

Fusarium head blight infection causes severe yield losses and contamination of the grain with mycotoxins in triticale (× Triticosecale Wittmack) grown in temperate and semihumid areas. In a two-year experiment thirty-six genotypes were inoculated separately with two isolates of Fusarium graminearum differing fivefold in their in vitro deoxynivalenol (DON) production and the effect on various traits was studied. All traits were significantly affected by head blight. The two isolates differed considerably in their aggressiveness resulting in a mean reduction of grain weight per spike of almost 25% and 50%, respectively. Inter-annual correlation was high for average disease rating (r=0.63, P<-0.01) and low for the other traits. Therefore, disease rating, averaged from two to three records, was regarded a suitable criterion for screening purposes. The effect of isolates on genotypes was not stable over years. The mean DON content of five genotypes with diverse resistance levels was 68 mg kg-1. In vitro DON production of the two isolates used for inoculation did not correspond to their aggressiveness and DON contamination of the grain.

Comparison of resistance of triticale, wheat and spelt to septoria nodorum blotch at the seedling and adult plant stages

On average, the cereal species studied were susceptible to septoria nodorum blotch (SNB), except for spring triticale on leaf and head and winter titicale on leaf, that appeared to be significantly more resistant, than the other ones. In all three species the SNB response of the adult plants was to a limited extent only predicted by the reaction on first leaf seedlings. In most cases it was impossible to predict the response to SNB of adult plants on the basis of seedling reaction. Correlations between the adult plant stage and the seedling stage, or detached seedling leaves, appears not to be sufficient for use in practical breeding work. A reversal of reaction to SNB was even found between the above growth stages in studied spring and winter wheat varieties.

Resistance in Triticale to the Russian Wheat Aphid (Homoptera: Aphididae)

The Russian wheat aphid, Diuraphis noxia (Mordvilko), has become a serious threat to wheat, Triticum spp., production in the western United States. The use of resistant wheat cultivars as a management strategy for this pest is highly desirable. Thus, several collections of wheat and related species have been tested to locate sources of resistance. The USDA-ARS National Triticale Collection, consisting of 731 lines, was one of the collections tested. Initial mass screening tests were done in greenhouse flats in environmental chambers. Seven triticale, xTriticosecale Wittmack, lines with varying degrees of resistance were identified. Four lines from Russia (PI 386148, PI 386149, PI 386150, and PI 386156) and one line from California (CI 82) were the most resistant in the screening tests. Additional tests were done with all seven lines to determine the mechanisms of resistance. Antibiosis appeared to be the most discernible mechanism of resistance, with significantly lower reproduction occurring on the triticales than on ‘TAM W-101’ wheat, Triticum aestivum L., or ‘Snoopy’ rye, Secale cereale L. Greater levels of resistance in the triticales over ‘TAM W-101’ were observed also in antixenosis and tolerance tests. The Russian triticales have been incorporated into the wheat breeding program for development of germplasm resistant to D. noxia .