Genetic variability of spelt factor gene in Triticum and Aegilops species

Abstract

Background Threshability, rachis fragility and spike shape are critical traits for the domestication and evolution of wheat, determining the crop yield and efficiency of the harvest. Spelt factor gene Q controls a wide range of domestication-related traits in polyploid wheats, including those mentioned above. The main goal of the present study was to characterise the Q gene for uninvestigated accessions of wheats, including four endemics, and Aegilops accessions, and to analyze the species evolution based on differences in Q gene sequences. Results We have studied the spike morphology for 15 accessions of wheat species, including four endemics, namely Triticum macha, T. tibetanum, T. aestivum ssp. petropavlovskyi and T. spelta ssp. yunnanense, and 24 Aegilops accessions, which are donors of B and D genomes for polyploid wheat. The Q-5A, q-5D and q-5S genes were investigated, and a novel allele of the Q-5A gene was found in accessions of T. tibetanum (KU510 and KU515). This allele was similar to the Q allele of T. aestivum cv. Chinese Spring but had an insertion 161 bp in length within exon 5. This insertion led to a frameshift and premature stop codon formation. Thus, the T. tibetanum have spelt spikes, which is probably determined by the gene Tg, rather than Q. We determined the variability within the q-5D genes among hexaploid wheat and their D genome donor Aegilops tauschii. Moreover, we studied the accessions C21–5129, KU-2074, and K-1100 of Ae. tauschii ssp. strangulata, which could be involved in the origin of hexaploid wheats. Conclusions The variability and phylogenetic relationships of the Q gene sequences studied allowed us to clarify the relationships between species of the genus Triticum and to predict the donor of the D genome among the Ae. tauschii accessions. Ae. tauschii ssp. strangulata accessions C21–5129, KU-2074 and K-1100 are the most interesting among the analysed accessions, since their partial sequence of q-5D is identical to the q-5D of T. aestivum cv. Chinese Spring. This result indicates that the donor is Ae. tauschii ssp. strangulata but not Ae. tauschii ssp. tauschii. Our analysis allowed us to clarify the phylogenetic relationships in the genus Triticum.

The Kishony Mega-Plate Experiment, a Markov Process

“…The Numerical Calculation of the Jukes-Cantor single-site Stationary and Non-stationary Models FORTRAN computer programs were written to compute the values for equations (11)(12)(13)(14) stationary model and equations (15-18) non-stationary model for two mutation rates, 1E-5 and 1E-9. The FORTRAN source code is supplied in the supplemental documentation as well as the data derived from these programs.…”

“…The Jukes-Cantor and derivative models are commonly used in an attempt to compute the evolutionary distance between different sequences of homologous genetic code. Some recent examples of applications of the Jukes-Cantor and derivative models can be found in the following references, [11][12][13][14][15]. The main difference between the Jukes-Cantor model and the derivative models listed above is derivative models allow for different mutation rates for the different elements of the transition matrix, for example, to address the fact that base transversions can have a different mutation rate than for base transitions.…”

Genetic Features of Triticale–Wheat Hybrids with Vaviloid-Type Spike Branching

“…These results imply a local deletion of the Q gene in the studied hybrids. Interestingly, Vavilova et al [ 29 ] did not obtain positive results during PCR amplifications of the Q gene in the accessions of T. vavilovii , which is the species for which this type of spike branching was named. This result may also indicate a gene Q deletion in T. vavilovii .…”