Dietary fiber content of bulgurs prepared from different wheat varieties was investigated. Grains of 29 Turkish wheat cultivars and advanced breeding lines (23 of durum and 6 of common wheat) were used in this study. The average values for ADF and NDF (+amylase) contents of investigated durum wheats were 3.4% and 9.9%, respectively and the corresponding values of common wheats were 3.4% and 11.5%. In this study, the average values for ADF and NDF (+amylase) contents of bulgurs made of durum wheats were found to be 5.4% and 10.3%, respectively and the corresponding values of bulgurs made of common wheats were 5.8% and 11.7%. The minimum and maximum values for ADF and NDF (+amylase) contents of bulgurs made of durum wheats were found to be 4.1%-6.8% and 7.9%-11.8%, respectively and the corresponding values of bulgurs made of common wheats were 5.1%-6.4 and 10.6%-12.4%. The processing of wheat into bulgur generally increased the levels of ADF and NDF(+amylase) contents. It can be concluded that bulgur is at least as good as a raw wheat in terms of dietary fibre content. Although there is no essential change in the total protein content, ash and ß-carotene contents of the bulgurs were lower than the ones in the original wheats as a result of debranning.
Authors:Q. Mo, C.Y. Wang, C.H. Chen, Y.J. Wang, H. Zhang, X.L. Liu, and W.Q. Ji
Thinopyrum ponticum (2n = 10x = 70) has donated rust resistance genes to protect wheat from this fungal disease. In the present study, the line ES-7, derived from the progeny of the crosses between common wheat cultivar Abbondanza and Triticum aestivum–Th. ponticum partial amphiploid line Xiaoyan784, was characterized by cytological, fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH) and EST-STS marker techniques. Cytological observations revealed that the configuration of ES-7 was 2n = 42 = 21 II. GISH and FISH results showed that ES-7 had two St chromosomes and lacked 5A chromosomes compared to common wheat. The 4A chromosome of ES-7 had small alterations from common wheat. Two EST-SSR markers BE482522 and BG262826, specific to Th. ponticum and tetraploid Pseudoroegneria spicata (2n = 4x = 28), locate on the homoeologous group 5 chromosomes of wheat, could amplify polymorphic bands in ES-7. It was suggested that the introduced St chromosomes belonged to homoeologous group 5, that is, ES-7 was a 5St (5A) disomic substitution line. Furthermore, ES-7 showed highly resistance to mixed stripe rust races of CYR32 and CYR33 in adult stages, which was possibly inherited from Th. ponticum. Thus, ES-7 can be used for wheat stripe rust resistance breeding program.
Authors:G. Gulyás, M. Rakszegi, Z. Bognár, L. Láng, and Z. Bedő
The genetic diversity of cultivated spelt (Triticum aestivum ssp. spelta) presently is narrow. Evaluation of germplasm collections of spelt on quality level supplemented with DNA analysis is, therefore, of great importance. This study was designed to help the evaluation process for the selection of new spelt varieties with a support of molecular characterization. A total of 30 genotypes, including two common wheat varieties, were included in the evaluation of genetic diversity on quality and DNA levels. According to the quality attributes, spelt flours exhibited medium rheological parameters and many of them had average gluten quality. AFLP analysis was conducted to evaluate phylogenetic relationships and the genetic diversity present in the accessions. A high level of genetic diversity was revealed by the very high PIC values. Two main clusters could be separated on the dendrogram: a cluster with genotypes that have common wheat in their pedigree and another cluster consisting of pure spelt accessions. The extent of genetic diversity in the spelt germplasm collections was confirmed not only by molecular markers but on the basis of quality assessment.
Authors:G. Mangini, D. Nigro, B. Margiotta, P. De Vita, A. Gadaleta, R. Simeone, and A. Blanco
During the last century wheat landraces were replaced by modern wheat cultivars leading to a gradual process of genetic erosion. Landraces genotyping and phenotyping are strategically useful, as they could broaden the genetic base of modern cultivars. In this research, we explored Single Nucleotide Polymorphism (SNP) markers diversity in a collection of common and durum wheats, including both landraces and Italian elite cultivars. A panel of 6,872 SNP markers was used to analyze the genetic variability among the accessions, using both the Principal Components Analysis (PCA) and the Neighbour Joining clustering method. PCA analysis separated common wheat accessions from durum ones, and allowed to group separately durum landraces from durum elite cultivars. The Neighbour joining clustering validated PCA results, and moreover, separated common wheat landraces from common elite cultivars. The clustering results demonstrated that Italian durum landraces were poorly exploited in modern breeding programs. Combining cluster results with heterozygosity levels observed, it was possible to clarify synonymy and homonymy cases identified for Bianchetta, Risciola, Saragolla, Timilia and Dauno III accessions. The SNP panel was also used to detect the minimum number of markers to discriminate the studied accessions. A set of 33 SNPs were found to be highly informative and used for a molecular barcode, which could be useful for cultivar identification and for the traceability of wheat end-products.
Seven synthetic hexaploid wheats (Triticum dicoccum/Aegilops tauschii) were subjected for investigation. Numerical variation of chromosome number in F1 hybrids between three synthetics and common wheat varieties, was recorded. Hexaploid amphiploids (SHW) formed gametes with aneuploid chromosome number at a frequency of 13.2 and 14.8% as male and female parents, respectively. We speculated that the frequency of aneuploids in the generation might depend on variability of BAu- and D-genomes of synthetic parents, and could be used for increasing the genetic diversity in common wheat. The HMW-glutenins analysis divided two lines in SHW530 and 532 due to different genes present in the B-genome, and increased them to 9 synthetic lines. The subunits 1Dx1.5 + 1Dy10 was predominantly observed in the synthetics. Two other allelic variants 1Dx2 + 1Dy11 and 1Dx4 + 1Dy10.1 were found in four lines and appeared as new genes in SHW originated from Aegilops tauschii. The synthetic hexaploid lines could play a significant role as novel germplasm resources for improving the grain quality of bread wheat.
Authors:G.J. Ye, L. Wei, W.J. Chen, B. Zhang, B.L. Liu, and H.G. Zhang
Red coleoptile is an easily observed trait in Triticum aestivum and can provide some protection against stress. Here, TaMYB-A1 or TuMYB-A1, homologous to TaMYB-D1, which controls red coleoptile formation in the common wheat cultivar ‘Gy115’, was isolated from eight T. aestivum and 34 T. urartu cultivars. The genome sequence of TaMYB-A1 was 867 bp with an intron of 93 bp, which was similar to the MYBs regulating anthocyanin biosynthesis in T. aestivum but different from other MYB transcription factors regulating anthocyanin biosynthesis. TaMYB-A1 had an integrated DNA-binding domain of 102 amino acids and a transcriptional domain of 42 amino acids, which was responsible for regulating anthocyanin biosynthesis. TaMYB-A1 was assigned to the same branch as the MYBs regulating anthocyanin biosynthesis in a phylogenetic tree. A transient expression analysis showed that TaMYB-A1 induced ‘Opata’ coleoptile cells to synthesize anthocyanin with the help of ZmR. A non-functional allele of TaMYB-a1 existed in common wheat cultivars containing rc-a1. One single nucleotide was deleted 715 bp after the start codon in TaMYB-a1 compared with TaMYB-A1. The deletion caused a frame shift mutation, destroyed the DNA transcription activator domain, and resulted in TaMYB-a1 losing its ability to regulate anthocyanin biosynthesis in ‘Opata’ coleoptile cells. Those cultivars with functional TaMYB-A1 or TuMYB-A1 have red coleoptiles. The isolation of TaMYB-A1 should aid in understanding the molecular mechanisms of coleoptile traits in T. aestivum.