Thinopyrum distichum addition lines: production, morphological and cytological characterisation of 11 disomic addition lines and stable addition-substitution line

Abstract

Plants of the partial amphiploid Inia 66/Thinopyrum distichum (2n = 70)//Inia 66 (2n = 56) were used as male parents in crosses with the monosomic series in the common wheat cultivar Inia 66. The genome and homoeologous group of the monosomic used in the cross affected the distribution of chromosome number of the progeny plants in the F2 and F4. Meiosis in the pollen mother cells of the B1F7 partial amphiploids was not stable, and not different from that of the B1F1 in which univalents and multivalents were observed. Disomic addition lines were selected on the basis of morphology and meiotic stability in the F2, F4 and F5. Eleven of the fourteen possible wheat-Th. distichum disomic addition lines were identified using chromosome C-band pattern, as well as size and arm ratio, as genetic markers. Addition of T. distichum chromosome J (dll) produced a phenotype indicating homoeology with wheat group-2 chromosomes. Clear indications of homoeology based on morphological characteristics were not obtained in any of the other addition lines, probably due to the mixed homoeology of the Th. distichum chromosomes relative to wheat. The addition lines were all susceptible to leaf rust, unlike the germplasm-line Indis which carries a leaf rust resistance gene on a translocation segment derived from Th. distichum. Instability of meiotic pairing was observed in all addition lines. The stability, or not, of progeny chromosome counts did not reflect the level of chromosome pairing instability in the parental plants. SDS-PAGE for gliadin-type seed proteins revealed two addition lines which expressed seed storage proteins uncommon to Inia 66 but typical of Th. distichum.

Influence of alien chromosomes on the resistance of soft wheat to biotrophic fungal pathogens

“…According to the data of Li et al [23], the resistance gene against powdery mildew is localized on the short arm of chromosome 6V of the species H. villosa. All the addition lines and amphiploids were susceptible [8]. However, our evaluation of the line T. aestivum × H. villosa 6AL/6VS with the Pm21 genome from H. villosa demonstrated that it is highly effective under the conditions of Belarus [2].…”

Chromosome duplication causing gene‐dosage‐based effects on the gene expression level in Gossypium hirsutum‐Gossypium australe addition lines

“…australe monosomic addition lines (MAs) were successfully developed (Chen et al, 2014). Compared to MAs, disomic addition lines (DAs) are more stable because the two identical alien chromosomes generally form a bivalent during meiosis (Littlejohn and Pienaar, 1995; Wang et al, 2016). As DAs contain a pair of homologous chromosomes from the alien donor species, the transcriptional profile may be different between DAs and MAs.…”

Identification ofThinopyrum distichumchromosomes responsible for its salt tolerance

“…distichum with common and durum wheat were found to be no more salt tolerant than the Triticum parents as the genes concerned appear to be suppresse~ by the wheat genomes (Littlejohn, 1988). Littlejohn and Pienaar (1995) developed eleven common wheat Th. distichu'm disomic addition lines and related the extra chromosomej in each to a C-band karyotype of Th.…”