Authors:J. Jia, G. Li, C. Liu, M. Lei, and Z. Yang
Wheat yellow rust resistance gene Yr17 was originated from the wheat-Aegilops ventricosa introgression, and still effective on the adult plant in Southern China. The previous studies located the gene Yr17 on the translocation of 2NS-2AS using the molecular and cytological markers. In the present study, we screened new PCR-based markers to map the gene Yr17 region from the investigation of a segregating 120 F2 population. All markers including four EST-PCR markers, a SCAR (sequence characterized amplified region) and a PLUG (PCR based landmark unique gene) marker specific to Yr17 gene were mapped on the chromosome 2AS, and located on the chromosomal deletion bin 2AS5-0.8–1.00 region. Based on the wheat-rice collinearity, we found that the sequences of the Yr17 gene linked markers were comparatively matched at rice chromosome 4 and chromosome 7. However, the identified closely linked genomic sequence of Yr17 gene is most likely collinear with genomic region of rice chromosome 4. The newly produced PCR based markers closely linked to Yr17 gene will be useful for the marker-assisted selection in wheat breeding for rust resistance.
The main criterion that determines the quality of durum wheat is the degree of suitability for pasta production (pasta-processing quality). In this regard, pigment content and the quantity of oxidative enzymes of durum wheat play important roles in the quality of pasta. It is now possible to examine these features and specify their effects using recently developed genetic markers and spectrophotometric measurement techniques. In the present study, LOX enzyme activity and pigment content are determined using molecular and biochemical scanning. According to the obtained results, Gediz-75, Gdem-12, Line-19, Zenit, Line-7 and Line-20 were determined as the most suitable lines or varieties for the production of quality pasta with regard to LOX enzyme activity. As for pigment content, Kyle, Zenit, Gdem-12, Gdem-2, TMB-1 and TMB-3 showed the highest potential for the production of yellow pasta. When pigment content and LOX enzyme activity were evaluated together, the potential of the Gediz-75, Gdem-12 and Zenit durum wheat varieties and lines to produce yellow pasta products was shown to be very high.
Authors:Mária Höhn, L. Hufnagel, Klára Cseke, and G. Vendramin
We investigated the diversity pattern of nine Swiss stone pine (Pinus cembra L.) populations along the Carpathian range including the High Tatras, by using six chloroplast DNA microsatellites (cpSSR). Our aim was to detect genetically distinct regions by clustering of populations, and to tackle possible historical colonization routes. Our analysis referred to an investigated geographical range with the two most distant populations situated at about 500 air km. We found that the most diverse populations are situated at the two edges of the investigated part, in the Retezat Mts. (South Carpathians) and the High Tatras, and diversity decreases towards the populations of the Eastern Carpathians. Hierarchical clustering and NMDS revealed that the populations of the South Carpathians with the Tatras form a distinct cluster, significantly separated from those of the Eastern Carpathians. Moreover, based on the most variable chloroplast microsatellites, the four populations of the two range edges are not significantly different. Our results, supported also by palynological and late glacial macrofossil evidences, indicate refugial territories within the Retezat Mts. that conserved rich haplotype composition. From this refugial territory Pinus cembra might have colonized the Eastern Carpathians, and this was accompanied by a gradual decrease in population diversity. Populations of the High Tatras might have had the same role in the colonizing events of the Carpathians, as positive correlation was detected among populations lying from each other at a distance of 280 km, the maximum distance between neighbouring populations.
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.
Several molecular markers have been reported for the detection of the 1RS chromosome arm. The aim of the present experiments was to study the reliability and reproducibility of six molecular markers specific to the 1RS rye chromosome (GPI, Bmac213, 5S, IAG95, SCM9 and RMS13) in distinguishing between wheat genotypes with and without the 1BL.1RS or 1AL.1RS translocations. In the course of the analysis, PCR products of the expected size were obtained with all the markers, which were found to give a reliable indication of the presence of the 1RS chromosome arm in the wheat genome.