Identification of Bread and Durum Wheats from their Diploid Ancestral Species Based on Chloroplast DNA

Abstract Species that have been identified as the genome donors to cultivated polyploid durum and bread wheats (Triticum durum L. and T. aestivum L., respectively) are potential gene sources for the breeding of these two crops. Therefore, their accurate identification facilitates their use in the improvement of these crops. Based on chloroplast DNA analysis (rpL2 and rps16 introns, psbC-trnS, trnT-L, and trnL-F) using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP), an attempt was made in 2018 (Department of Molecular Biology and Biotechnology/AECS) to identify durum and bread wheats from each of their proposed diploid ancestral species (i.e., T. monococcum, T. urartu, Aegilops speltoides, and Ae. tauschii). The use of two PCR markers (psbC-trnS and trnL-F) and three PCR-RFLP locus-enzyme combinations (rps16 intron-Tru 1I, rpL2 intron-Taq I, and trnT-L-Taq I) allowed the identification of all species involved. Reliable and accurate identification of diploid ancestors of durum and bread wheats using these candidate species-specific cpDNA markers will be useful for wheat breeding programs, in situ and ex situ conservation efforts, verification of seed purity in commercial seed stocks, and ensuring identity and integrity of accessions held within a collection does not change through unwanted gene flow or by genetic drift after regeneration by seed.