Authors:S. Tahmasebi, B. Heidari, H. Pakniyat, and A. Dadkhodaie
The 1BL/1RS wheat-rye translocations had been used in wheat breeding programs worldwide. The objective of this study was to determine the effect of the 1BL/1RS translocation in SeriM82 /Babax recombinant population. 167 lines of this population were assayed under well-irrigated, terminal drought, heat and a combination of heat and drought stress conditions in two years. 5S rDNA and Iag95 markers were used to differentiate genotypes with or without the1BL/1RS translocation. Presence of 1BL/1RS translocation reduced grain yield (YLD), grain per spike (GSP) and grain per m2 (GM2). QTLs in 1 BL/1RS segments indicated increased thousand-grain weight (TGW), chlorophyll content, spikelet per spike (SPLS), spike compactness (SCOM) and awn length (AWL) but reduced YLD, GSP and GM2. The 1BL/1RS carrying lines’ response varied between assayed environments. Plants of drought trials were more affected by 1BL/1RS compared to others. Differences in the effects of 1BL/1RS and QTLs suggest that gene expression at translocation loci is restricted to specific environmental conditions. In general, the 1BL/1RS translocation could not be a suitable source of genetic diversity for enhancing grain yield under heat and drought stresses.
Authors:E. Gregová, D. Mihálik, S. Šliková, and Z. Šramková
High molecular weight glutenin and
translocation employing the standard sodium dodecyl sulphate (SDS-PAGE) and acid (A-PAGE) polyacrylamide gel electrophoresis methods were classified in 43 Slovak wheat cultivars registered between 1976 and 2006. Total number of 9 alleles was detected at all
loci. The most frequent HMW-GS alleles were “Null” for
, 7+9 for
and 5+10 for
, respectively. At the same time these alleles also constituted the most frequent HMW-GS genotype and phenotype-0, 7+9, 5+10. Such HMW-GS combination was found in 48.8% of all genotypes analyzed in
. Eleven different HMW-GS genotype-phenotype combinations were found, occurring at various frequencies.
Authors:K.J. Deng, J.P. Zhou, X.H. Wu, G. Sun, T. Wang, A.T. Tang, X.L. Zheng, and Y. Zhang
It is well demonstrated that wheat-rye 1BL/1RS translocated chromosome leads to some valuable novel traits such as disease resistance, high yield and functional stay-green after anthesis. To understand the physiological mechanism of 1BL/1RS translocation responsible for osmotic stress, two wheat cultivars, CN12 and CN17, carrying the translocated chromosome and MY11 without the translocated chromosome were employed in the study. During 5-day osmotic stress, fresh weight inhibition, chlorophyll content, soluble protein content, MDA concentration, antioxidant enzymes activity and free polyamines content were examined. CN12 and CN17, especially cultivar CN17, registered greater biomass and minor oxidative damage compared with their wheat parent. Meanwhile, the concentration of Spd and Spm in CN17 was significantly higher than the others. In addition, we found a positive correlation of fresh weight inhibition (FWI) and Put concentration, and a negative one with the parameters (Spd + Spm): Put ratio, indicating the importance of higher polyamine (Spd and Spm) accumulation on the adaptation to osmotic stress. Therefore, we proposed that the accumulation of higher polyamines (Spd and Spm) should play an important role on the adaptation of 1BL/1RS translocation lines to osmotic stress and might be important factors for the origin of novel traits introduced by 1BL/1RS.
Six different 1RS-specific molecular markers (RMS13, Bmac213, GPI, 5S, SCM9, IAG95) were tested in twenty rye cultivars of various origin. The aim of the experiments was to choose rye cultivars which give polymorphic PCR products with these 1RS-specific markers compared to the wheat cultivar Mv Magdaléna, which contains the 1BL.1RS translocation. The polymorphic rye cultivars can be presumed to differ from the 1BL.1RS translocation originating from the Petkus rye cultivar and will hopefully carry effective resistance genes which can be incorporated into the 1BL.1RS translocation in wheat. Twenty rye cultivars (at least two plants per cultivar) were analysed with these markers. Of fifty-two rye samples analysed, three plants were found to be polymorphic, one (Kisvárdai Alacsony from Hungary), for the 5S marker, one (Kriszta from Hungary) for the RMS13 marker and one (Porto from Portugal) for the SCM9 marker. The polymorphic plants were grown to maturity in the phytotron.
Authors:N. Niu, Y. L. Song, F. Wei, H. M. Liu, S. M. Ma, H. Y. Zhao, and G. S. Zhang
In this study, we employed electron microscopy to investigate the cytogenetic and embryologic mechanisms of parthenogenesis induced in the 1BL/1RS male sterile lines of wheat. Analysis of the root tips and acid polyacrylamide gel electrophoresis indicated that all of the male sterile lines and their maintainer lines were 1BL/1RS translocation lines, whereas the restorer lines were non-1BL/1RS translocation lines. Furthermore, the chromosomes of 1BL/1RS wheat lines with T. aestivum cytoplasm and Aegilops cytoplasm (include Ae. kotschyi, Ae. ventricosa, Ae. variabilis) paired abnormally at different rates during meiotic metaphase I (MMI). The translocated segment size of the 1RS chromosome and the specific nuclear–alloplasm interaction impaired the pairing of homologous chromosome in the background of the specific Aegilops cytoplasm at MMI. In addition, the frequency of abnormal chromosomal pairing was directly affected by the frequency of haploid production induced by parthenogenesis. The results of this study provide significant insights into the mechanism of parthenogenesis, which is probably due to the abnormal fertilization of synergid cells in alloplasmic 1BL/1RS wheat.