[Intraspecific divergence in wheats of the Emmer group using in situ hybridization with the Spelt1 family of tandem repeats].
Fluorescence in situ hybridization (FISH) was used to study the distribution of Spelt1 repetitive DNA sequences on chromosomes of 37 accessions representing eight polyploidy wheat species of the Emmer evolutionary lineage: Triticum dicoccoides Körn, T. dicoccum (Schrank) Schuebel, T. durum Desf., T. polonicum L., T. carthlicum Nevski, T. aethiopicum Jabbz., T. aestivum L., and T. spelta L. Substantial polymorphism in the number, distribution, and the sizes of the Spelt1 loci was revealed. On the chromosomes of the accessions examined, Spelt1 tandem repeats were found in seven different positions (per haploid chromosome set). These were "potential hybridization sites", including the subtelomeric regions of either short or long arms of chromosomes 2A and 6B, the short arm of chromosome 1B, and the long arms of chromosomes 2B and 3B. However, in individual genotypes, only from one to three Spelt1 loci were revealed. Furthermore, no hybridization with Spelt1 probe was detected on chromosomes from 12 accessions. Thus, the total number of Spelt1 sites in karyotypes varied from zero to three, with the average number of 1.16. This was substantially lower than in the species of the Timopheevi section and diploid Aegilops speltoides Tausch, a putative donor of the B genome. The decrease of the content of Spelt1 sequences in the genomes of the Emmer group wheats in comparison with the species of the Timopheevii group and diploid Ae. speltoides was assumed to result from the repetitive sequences reorganization during polyploidization and the repeat elimination during wheat evolution.
Zoshchuk
S A
SA
Zoshchuk
N V
NV
Amosova
A V
AV
Dedkova
O S
OS
Badaeva
E D
ED
D002874:Chromosome Mapping / Q000379:methods; D032461:Chromosomes, Plant / Q000235:genetics*; D019143:Evolution, Molecular; D017403:In Situ Hybridization; D011110:Polymorphism, Genetic; D040641:Quantitative Trait Loci / Q000235:genetics*; D020080:Tandem Repeat Sequences / Q000235:genetics*; D014908:Triticum / Q000235:genetics*