Authors:Z.L. Li, H.Y. Li, G. Chen, X.J. Liu, C.L. Kou, S.Z. Ning, Z.W. Yuan, M. Hao, D.C. Liu, and L.Q. Zhang
Seven Glu-A1m allelic variants of the Glu-A1mx genes in Triticum monococcum ssp. monococcum, designated as 1Ax2.1a, 1Ax2.1b, 1Ax2.1c, 1Ax2.1d, 1Ax2.1e, 1Ax2.1f, and 1Ax2.1g were characterized. Their authenticity was confirmed by successful expression of the coding regions in E. coli, and except for the 1Ax2.1a with the presence of internal stop codons at position of 313 aa, all correspond to the subunit in seeds. However, all the active six genes had a same DNA size although their encoding subunits showed different molecular weight. Our study indicated that amino acid residue substitutions rather than previously frequently reported insertions/deletions played an important role on the subunit evolution of these Glu-A1mx alleles. Since variation in the Glu-A1x locus in common wheat is rare, these novel genes at the Glu-A1mx can be used as candidate genes for further wheat quality improvement.
High-molecular-weight glutenin subunits (HMW-GSs) are important seed storage proteins associated with bread-making quality in common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD). Variation in the Glu-A1x locus in common wheat is scare. Diploid Triticum monococcum ssp. monococcum (2n = 2x = 14, AmAm) is the first cultivated wheat. In the present study, allelic variations at the Glu-A1mx locus were systematically investigated in 197 T. monococcum ssp. monococcum accessions. Out of the 8 detected Glu-A1mx alleles, 5 were novel, including Glu-A1m-b, Glu-A1m-c, Glu-A1m-d, Glu-A1m-g, and Glu-A1m-h. This diversity is higher than that of common wheat. Compared with 1Ax1 and 1Ax2*, which are present in common wheat, these alleles contained three deletions/insertions as well as some single nucleotide polymorphism variations that might affect the elastic properties of wheat flour. New variations in T. monococcum probably occurred after the divergence between A and Am and are excluded in common wheat populations. These allelic variations could be used as novel resources to further improve wheat quality.
Authors:J. Ahmadi, A. Pour-Aboughadareh, S. Fabriki-Ourang, and A. A. Mehrabi
Glutenin and gliadin subunits play a key role in flour processing quality by network formation in dough. Wild relatives of crops have served as a pool of genetic variation for decades. In this study, 180 accessions from 12 domesticated and wild relatives of wheat were characterized for the glutenin and gliadin genes with allele-specific molecular markers. A total of 24 alleles were detected for the Glu-A3 and Gli-2A loci, which out of 19 amplified products identified as new alleles. Analysis of molecular variance (AMOVA) indicated that 90 and 65% of the genetic diversity were partitioned within two Aegilops and Triticum genera and their species, respectively. Furthermore, all glutenin and gliadin analyzed loci were polymorphic, indicating large genetic diversity within and between the wild species. Our results revealed that allelic variation of Glu-3A and Gli-As.2 is linked to genomic constitutions so that, Ae. caudata (C genome), Ae. neglecta (UM genome), Ae. umbellulata (U genome) and T. urartu (Au genome) harbor wide variation in the studied subunits. Hence, these species can be used in wheat quality breeding programs.
Authors:P. Mijić, I. Knežević, M. Baban, M. Domaćinović, and D. Rimac
Recently secondary cattle selection traits have been given more attention in developed cattle breeding countries in establishing a selection index. In this way, milking traits have acquired a prominent place. This paper aimed to determine coefficients of correlation and regression between a number of milking traits, that could be helpful in establishing a selection index for breeding bulls and their dams. A further goal was to determine the distribution of milking parameters. The data of 303 Holstein Friesian and 235 Simmental cows were analysed. The results showed that in both cow breeds correlations existed between milk yield and average milk flow (0.39 and 0.49), as well as between milk yield and milking time (0.53 and 0.35). Negative correlations were found between average milk flow and milking time (-0.49 and -0.56). For the Holstein Friesian breed, 67.0% of the cows had a total milk flow in the range of 1.61 to 3.60 kg/min, whereas in the Simmental breed 72.2% of the cows had a total milk flow of 2.40 kg/min. The milk flow rate can be indirectly affected by selecting cows with higher milk production. The definition of an optimal milk flow rate and the determination of breeding goals for milking traits will lead to faster progress in milking trait improvement and an easier choice of quality breeding bulls and dams.
Hristov, N., Mladenov, N., Djuric, V., Kondic-Spika, A., Marjanovic-Jeromela, A., Simic, D. 2010. Genotype by environment interactions in wheat qualitybreeding programs in southeast Europe. Euphytica 174 :315