Leaf rust (LR) is one of the most common diseases of wheat. The resistance gene Lr29 provides wide resistance to LR, but loses its function under high temperatures. Despite the importance of this gene, the mechanism of resistance is unclear. In this study we investigated the resistance mechanism of the Lr29 gene to LR at the seedling stage, as well as the reasons behind the loss of gene function at high temperatures by using integrated transcriptome and metabolome analyses. Results suggests that the pathways of reactive oxygen species (ROS), which could be due to expression of genes including LOX (lipoxygenase), APX (ascorbate peroxidase) and GST (glutathione S-transferase), play a key role in the resistance of Lr29 to LR, furthermore flavonoids, such as epicatechin, cosmosiin, apiin, vitexin and rutin, were identified as the key metabolites linked to Lr29 resistance. We also found that, at high temperatures, Lr29 downregulated the genes and metabolites associated with glycolysis and the tricarboxylic acid (TCA) cycle, while genes and metabolites related to the shikimic acid pathway were upregulated. This study might provide a valuable theoretical foundation for the cloning of the Lr29 gene, the analysis of its disease resistance mechanism, and the understanding of how temperature affects gene function.

Stripe or yellow rust (Yr), caused by Puccinia striiformis Westend. (Pst), is one of the most important wheat diseases worldwide. New aggressive Pst races can spread quickly, even between countries and continents. To identify and exploit stripe rust resistance genes, breeders must characterize first the Pst resistance and genotypes of their cultivars. To find new sources of resistances it is important to study how wheat varieties respond to Pst races that predominate in other continents. In this study we evaluated stripe rust resistance in 53 Hungarian winter wheat cultivars in China. Twenty-four cultivars (45.3%) had all stage resistance (ASR) and 1 (1.9%) had adult-plant resistance (APR), based on seedling tests in growth chambers and adult-plant tests in fields. We molecularly genotyped six Yr resistance genes: Yr5, Yr10, Yr15, Yr17, Yr18, and Yr36. Yr18, an APR gene, was present alone in five cultivars, and in ‘GK Kapos’, that also had seedling resistance. The other five Yr genes were absent in all cultivars tested.

Leaf rust, caused by Puccinia recondita f. sp. tritici, is one of the major diseases of wheat in Kazakhstan. To effectively use leaf rust resistance genes (Lr), it is important for breeders to know the resistance genotype in current cultivars. In this study, 30 winter wheat entries grown and/or produced in Kazakhstan were investigated using molecular markers to determine the presence and absence of eight important Lr genes. Molecular screening of these genotypes showed contrasting differences in the frequencies of these genes. Among the 30 entries, 17 carried leaf rust resistance gene Lr1, six had Lr26 and Lr34, and Lr10 and Lr37 were found in three cultivars. Two single cultivars separately carried Lr19 and Lr68, while Lr9 was not detected in any genotypes in this study. Field evaluation demonstrated that two of the most frequent two genes (Lr1 and Lr26) to be ineffective. While Lr34 provided some protection, the remaining effective Lr genes were found only in few genotypes: Lr37 occurred in Kazakh genotypes L-1090 and Krasnovodapadskaya 210 and in the US cultivar Madsen; Lr19 and Lr68 were likely present only in Russian and Kazakh cultivars, Pallada and Yegemen, respectively. The highest resistance over three years of leaf rust testing was found in Kazakh cultivars, Karasay, Krasnovodapadskaya 210, L-1090, Arap and Yegmen, foreign cultivars Madsen, Pallada and the control Parula (Lr68). Data may assist breeders to incorporate effective Lr genes into new cultivars.

Wheat leaf rust is an important disease of wheat, which causes economic damage to the country. Epiphytotic diseases of wheat rust cover the entire continents leading to catastrophic crop failures. In order to control the stability, it is very important to have available molecular genetic markers linked to these symptoms. As a result of the phytopathological evaluation of susceptibility to rust on the background of infectious diseases, we selected a number of samples resistant to Puccinia recondite f. sp. tritici using the following molecular markers: F1.2245/Lr10-6/r2, csLV34, LN2/Ventriup and csGS-F/R. We identified 20 samples resistant to wheat stem rust. From the studied wheat material we identified nine samples with Lr10 gene, one with Lr34/Yr18 genes, 2 with complex genes Lr37/Sr38/Yr17 and 10 samples with Lr68 genes. The most valuable donor of sustainability is a promising line Almaly/Obriy, where 3 resistance genes Lr34/Yr18, Lr37/Sr38/Yr17, Lr68 and Yr2 were identified as well as Oktyabrina line with 2 resistance genes Lr10 and Lr68. Our results provide an opportunity to move the selection process in Kazakhstan to a new scientific level by using molecular genetic techniques and technologies of MAS-breeding.

The genetic background of Fusarium head blight (FHB) resistance in the moderately resistant wheat variety Frontana was investigated in the GK Mini Manó/Frontana DH population (n = 168). The plant material was evaluated across seven epidemic environments for FHB, Fusarium-damaged kernel (FDK) and deoxynivalenol (DON) contents caused by two Fusarium species (F. culmorum and F. graminearum). The effects of phenotypic traits such as plant height and heading date were also considered in the experiments. In the population, 527 polymorph markers (DArT, SSR) within a distance of 1,381 cM distance were mapped. The quantitative trait locus/loci (QTL) on chromosomes 4A and 4B demonstrated a significant linkage only with FHB, while QTL on chromosomes 3A, 4B, 7A and 7B were linked to DON accumulation alone. Regions determining all the investigated Fusarium resistance traits were identified on chromosomes 1B, 2D, 3B, 5A, 5B and 6B. The markers in these regions are of the greatest significance from the aspect of resistance breeding. Our results indicate that the genetic background of resistance against FHB, FDK and DON accumulation can differ, and all these traits should be taken under consideration during resistance tests. Moreover, this is the first report on the mapping of Frontana-derived QTL that influence DON accumulation, which is important since the level of DON contamination determines the actions of the food and feed industries. Selection should therefore also focus on this trait by using molecular markers linked to DON content.

In 2014, was an extremely early and heavy yellow rust (Puccinia striiformis var. striiformis) epidemic in Hungary. Significant differences were among locations, years and genotypes in the severity of infection. Ratio of the resistant and moderately resistant genotypes was higher under bio environment. The yellow rust epidemic caused significant yield decreasing in the tested winter cereals.

Fusarium head blight (FHB) is a devastating disease of wheat (Triticum aestivum L.). This study investigated a `Frontana/Remus' doubled haploid population (n = 210 lines) to map and validate the `Frontana' resistance quantitative trait loci (QTL) focusing on Fusarium-damaged kernels (FDK). The plant material was evaluated in six epidemic situations for Fusarium resistance in inoculated field experiments, with either Fusarium graminearum or F. culmorum. Other studies have focused on FHB QTL, but it is important to evaluate how far these QTL determine FDK values. The data show that the genetic regulation of FHB resistance is more complex than earlier proposed. FHB resistance QTL were identified on chromosomes 3A, 4A and 6B. Markers showed association with FDK resistance on chromosomes 3D and at the marker Xs12m15_4. QTL on 2B, 4B, 5A and 7B chromosomes were responsible for both FHB and FDK resistance; in this case, the same QTL influenced both traits and possibly other traits during disease development. These QTL are very important, because they can be considered to be real Fusarium resistance QTL. The use of markers in breeding programmes, which are associated only with FHB or FDK resistance may be questionable and require further research. Heading date QTL were detected on chromosomes 1A, 2D and 7B overlapping with neither FHB nor FDK resistance QTL. The QTL identified in the `Frontana/Remus' population were in good agreement with earlier results from the literature.

Foliar fungal diseases such as rusts, powdery mildew and leaf spot diseases cause serious yield losses worldwide. In the Hungarian – Romanian cross-border region, leaf rust, powdery mildew and leaf spot diseases occur almost every year, and severe epidemics can cause 5-40% yield loss in susceptible cultivars. The occurrence of stem and yellow rust is less frequent, but due to the severity of infection, it can pose a great hazard for wheat production. The breeding and use of resistant cultivars offers an economical, safe and effective approach to protect wheat from these diseases. To use the advantages of breeding for disease resistance it is important for breeders to know the effects of diseases and the genetic background of the resistance in their cultivars. Alien chromosome translocations, such as the 1BL.1RS wheat-rye translocation, played an important role in providing new resistance sources for wheat. When used initially, this translocation conferred resistance to stem rust, stripe rust, leaf rust and powdery mildew (Sr31, Yr9, Lr26 and Pm8 genes). However, the Sr31 gene represented the main component of stem rust resistance in many wheat cultivars and remained effective for a long time. Some genes like the Lr34 leaf rust resistance gene inherit durable (non-racespecific) resistance, which is highly desirable for breeding programs. In this study, we assessed the severity and effect of the main foliar diseases on Hungarian and Romanian wheat cultivars. Wheat cultivars registered in Hungary and in Romania were also investigated using PCR based molecular markers to determine the presence or absence and frequency of the 1BL.1RS translocation and the Lr34 leaf rust resistance gene.

In Hungary, stem rust epidemics caused by Puccinia graminis f. sp. tritici are rare, but due to the severity of infection the stem rust fungus can pose a great hazard to wheat production. As new virulent races can appear, it is important for breeders to know of the genetic background of the stem rust resistance in their cultivars. In this study, 220 winter wheat cultivars registered in Hungary in the past 35 years were investigated using molecular markers to determine the presence or absence and frequency of the two important stem rust resistance genes Sr31 and Sr36. The results indicated that both Sr31 and Sr36 genes are widespread in wheat cultivars registered in Hungary. Sr31 was detected in 24.1% of these wheats, and Sr36 in 15.9%. These genes occurred to a somewhat larger extent in the 156 local cultivars: one-third (32.1%) had the Sr31 and 18.0% the Sr36 gene. Of these, 2 cultivars (1.3%) had both genes (Sr31+ Sr36). Among the 64 foreign cultivars only 3 (4.7%) carried the Sr31 gene. In the foreign group, Sr36 was only detected in the seven Croatian cultivars. Tests also revealed possible false pedigrees for some cultivars. Inoculation tests showed that both genes were still effective. One-sixth (16.7%) of stem rust resistant cultivars did not carry the target genes indicating the possible presence of other efficient Sr genes. Data may help breeders to incorporate effective Sr genes into new cultivars.

Plant growth is affected by various factors. The resistance of the plant to withstand various biotic and abiotic stress factors plays a vital role for its growth and development. In this study, we have characterized the resistance of various wheat cultivars to tan spot disease by the application of imaging techniques (such as: digital photography, chlorophyll fluorescence) under controlled conditions. The increase of the F0 chlorophyll fluorescence indicates the production of free chlorophylls, which may be involved in the defense reaction against the pathogen. The fluorescence data revealed changes of the photosynthetic apparatus at an early stage before the appearance of visual symptoms appeared, which could be used as an easily measurable markers of the infection.

The 1BL.1RS wheat-rye translocation and a wheat-Triticum timopheevii chromosomal introgression carry the Sr31, Lr26, Yr9 and Pm8 genes and the Sr36/Pm6 gene cluster, respectively. The objective of this study was to determine the distribution and impact of these two translocations in 220 wheat varieties registered in Hungary in the last 35 years until 2005. The 1BL.1RS translocation was introduced into Hungary via wheat cultivars ‘Avrora’ and ‘Kavkaz’, which were registered in 1970. New 1BL.1RS cultivars developed in Hungary first appeared in 1982. After reaching a maximum frequency of 50.0% among cultivars registered in Hungary in 1994, their presence declined steadily to 13.3% by 2005. The Sr36/Pm6 cultivars first appeared in 1980. Their frequency quickly reached 31.8% (1983–1984), but then dropped to between 9.6 and 18.5% (1990–2005). The two main Hungarian breeding programs showed opposing trends in the exploitation of these two translocations. In Martonvásár, 1BL.1RS played a dominant role, being present from 1993 to 1997 in ca. 95% of the released cultivars, while at the same time the use of Sr36/Pm6 was marginal. Conversely, among the Szeged cultivars, Sr36/Pm6 was present at high frequency (44.7% in 2002) with a low share of 1BL.1RS. In artificial field inoculation tests (1985–2003) both of the stem rust resistance genes provided significant resistance in all the years, though Sr36 proved more effective than Sr31. While Pm8 was not effective, except for the last 2 years, Pm6 exhibited significant resistance against powdery mildew in most of the 18 years tested. These data may help breeders to assess the usefulness of wheat-rye 1BL.1RS chromosome translocations and the Sr36/Pm6 resistance gene clusters in their future wheat improvement programs.

One of the important objectives of the research consists in the knowledge and new scientific progress share between neighbors of the Banat County. During the last years yield ability experiments were carried out in Romanian and Hungarian border localities such as: Timisoara, Lovrin, Cenad, Curtici and Szeged respectively. Romanian and Hungarian wheat varieties were tested. The plant capacity to fitt its biological peculiarities to yield a high amount of economical product was the main objective of this collaboration. The general yield average performed by varieties in Cenad and Szeged was insignificant (d=0.21t/ha). Alex and Kalász were the best varieties cultivated in Cenad. Alex and Holló performed the highest yield in Szeged conditions. Hungarian variety Verecke emphasized a high homeostasis associated with a high yield. In comparison with controls (Delia and Öthalom) the yield differences of Alex and Verecke were significant at P=0.001. The tolerance to biotic stress was ranging from medium-sensitive to sensitive on 40% and 42.9% of varieties cultivated in Cenad and Szeged respectively. From medium-resistant to resistant were Lovrin 34 (MR-R) and Verecke (MR).

Two hundred and twenty wheat cultivars registered in Hungary in a period of 35 years, from 1970 to 2005, were investigated by molecular markers to determine the frequency of Sr31 and the Sr36 stem rust resistance genes which are very effective in Hungary to date. Among the 156 Hungarian wheats a significant part (32.7%) had the 1RS.1BL wheat-rye chromosome translocation, the source of Sr31 gene, or the Triticum timopheevi introgression with Sr36 gene (17.3%). In the 64 foreign cultivars, deriving from 12 countries, only 4.7% had the 1RS.1BL and 10.9% carried the Sr36. The maximal frequency of cultivars with 1RS.1BL reached 47% (in 1994), and those of with Sr36 reached 32% (in 1983 and 1984). The occurrence of above genes in some wheat cultivars developed and produced in Romania was also investigated. Owning to the threat of new pathogen race Ug99 appeared in Uganda and which is virulent to Sr31 stem rust resistance genes there is an urgent need to incorporate several other Sr resistance genes against into the new wheat cultivars. Kivonat: Az utobbi 35 evben (1970-től 2005-ig) ketszazhusz Magyarorszagon elismert buzafajtat vizsgaltunk molekularis markerekkel, hogy meghatarozzuk a Magyarorszagon mindig nagyon hatasos Sr31 es Sr36 szarrozsda rezisztencia genek gyakorisagat. A vizsgalt 156 magyar buzafajtanak jelentős hanyada hordozta vagy az 1BL.1RS buzarozs kromoszoma transzlokaciot – az Sr31 rezisztenciagen forrasat (a fajtak 32,7%-a), vagy a Triticum timopheevi fajbol szarmazo Sr36 szarrozsda rezisztencia gent (17,3%). A 64 kulfoldi eredetű buzafajtabol (amelyek 12 orszagbol szarmaztak) csak 4,7% hordozta az 1BL.1RS-t es 10,9% az Sr36 rezisztencia gent. Az osszes vizsgalt buzafajtara vonatkoztatva az 1BL.1RS maximalis gyakorisaga 47%-ot (1994-ben) az Sr36 gene pedig 32%-ot (1983 es 1984) ert el. A fenti genek előfordulasat nehany Romaniaban előallitott es termelt buzafajtaban is megvizsgaltuk. Az Ugandaban megjelent uj, igen veszelyes, az Sr31 genre is virulens, patogen rassz (Ug99) jarvanyos terjedese miatt, a nemesites surgős feladata uj rezisztenciagenek beepitese a buzafajtakba.

Growing resistant wheat cultivars is considered to be an efficient and environmentally safe approach in reducing damage caused by leaf rust disease. Among the numerous leaf rust resistance genes of wheat, Lr52 is a very effective one with a broad spectrum resistance. The objective of this study was to identify and map molecular markers closely linked to the Lr52 resistance gene. Out of 280 RAPD, 44 SSR and 8 STS markers tested, three showed close linkage to the Lr52. In our study, one SSR marker (Xwmc149) showed a close linkage (11.3 cM) to the Lr52 gene. Another SSR (Xgwm234) and an STS (Xtxw200) markers, having close linkage to a recently identified leaf rust resistance gene found in PI 289824, also showed a close linkage (7.2 and 3.6 cM, respectively) to the Lr52. Matchings in the mapping distances of these markers linked to these resistance genes still remain open the possibility that the gene found in PI 289824 is identical to the Lr52, or simply this locate very close to it.

A set of Thatcher near-isogenic lines and two breeding lines were used to examine sequence tagged site (STS) markers linked to leaf rust resistance genes Lr9, Lr10, Lr19, Lr24, Lr28, Lr29, Lr35, and a simple sequenced repeat (SSR) marker for Lr39. The selected STS markers for resistance genes Lr9, Lr10, Lr19, Lr24 and Lr28 were identified in seven accessions by seven European laboratories. Near-isogenic lines of the spring wheat Thatcher were used as positive controls. Markers for resistance genes Lr9, Lr10, Lr19, Lr24 were identified in all seven laboratories as amplification products of 1100 bp, 310 bp, 130 bp and 310 bp, respectively. The STS markers linked to resistance genes Lr9, Lr10, Lr19, Lr24, Lr29, Lr35 and the SSR marker for Lr39 were robust and highly specific for these genes and will be useful in marker-assisted selection in wheat. However, the amplification product of 378 bp that corresponded with resistance gene Lr28 was detected in all accessions including genotypes lacking this gene in all seven laboratories. This marker needs to be improved.

The aim of this study was to find molecular markers (RAPD and SCAR) for the wheat leaf rust resistance gene Lr29. Among 81 RAPD primers tested, only one (OPY10) detected an additional band in the resistant NIL of Lr29. The genetic linkage of this molecular marker to Lr29 was tested on a segregating F2 population derived from a cross between the leaf rust resistant line and the susceptible parent GK Delibab. This marker was closely linked to the Lr29 gene. The polymorphic band was cloned and sequenced. Specific primers (SCAR) were synthesized and after amplification only resistant lines showed an amplified product. A second SCAR primer for another Lr29 RAPD fragment (UBC219, Procunier et al., 1995) was also designed and tested.