Aegilops-Secale amphiploids: chromosome categorisation, pollen viability and identification of fungal disease resistance genes

Abstract

The aim of this study was to assess the potential breeding value of goatgrass-rye amphiploids, which we are using as a “bridge” in a transfer of Aegilops chromatin (containing, e.g. leaf rust resistance genes) into triticale. We analysed the chromosomal constitution (by genomic in situ hybridisation, GISH), fertility (by pollen viability tests) and the presence of leaf rust and eyespot resistance genes (by molecular and endopeptidase assays) in a collection of 6× and 4× amphiploids originating from crosses between five Aegilops species and Secale cereale. In the five hexaploid amphiploids Aegilops kotschyi × Secale cereale (genome UUSSRR), Ae. variabilis × S. cereale (UUSSRR), Ae. biuncialis × S. cereale (UUMMRR; two lines) and Ae. ovata × S. cereale (UUMMRR), 28 Aegilops chromosomes were recognised, while in the Ae. tauschii × S. cereale amphiploid (4×; DDRR), only 14 such chromosomes were identified. In the materials, the number of rye chromosomes varied from 14 to 16. In one line of Ae. ovata × S. cereale, the U-R translocation was found. Pollen viability varied from 24.4 to 75.4%. The leaf rust resistance genes Lr22, Lr39 and Lr41 were identified in Ae. tauschii and the 4× amphiploid Ae. tauschii × S. cereale. For the first time, the leaf rust resistance gene Lr37 was found in Ae. kotschyi, Ae. ovata, Ae. biuncialis and amphiploids derived from those parental species. No eyespot resistance gene Pch1 was found in the amphiploids.

Genomic in situ Hybridization in Triticeae: A Methodological Approach

“…The Triticeae wild relatives continue to be important sources of genes for introducing agronomically desirable traits into common wheat and durum wheat (Triticum durum) [20][21]. Thus, alien gene transfer into common wheat via cross-species hybridization makes possible the resistance increasing to biotic and abiotic stresses as well as the quality improving [22][23].…”

Effective transfer of chromosomes carrying leaf rust resistance genes from Aegilops tauschii Coss. into hexaploid triticale (X Triticosecale Witt.) using Ae. tauschii × Secale cereale amphiploid forms

“…1 a). The Aegilops tauschii × S. cereale amphiploids, produced using embryo rescue by Sulinowski and Wojciechowska of the Institute of Plant Genetics, Polish Academy of Sciences, Poznań, Poland (data unpublished), carried 28 chromosomes having Lr22a and Lr39 (Kwiatek et al 2012 ) and Lr32 (data unpublished) markers connected with resistance to leaf rust. The aim of this study was: (1) to characterize the chromosome composition of the hybrids (BC 2 F 2 to BC 2 F 5 ) of Ae.…”

Cytogenetic analysis of Aegilops chromosomes, potentially usable in triticale (X Triticosecale Witt.) breeding

“…From our research perspective, this indicated a need for creating physical maps of cytogenetic markers of Aegilops accessions used in a further widening of the genetic diversity of triticale. The present work is a continuation of a research cycle (Kwiatek et al 2012), that deals with genetic diversification of cultivated triticale by introgressing alien Aegilops chromatin. Considering the progressive loss of effective resistance genes in triticale because of the appearance of new virulent disease pathotypes (Arseniuk 1996), the adaptation of methods used in gene transfer from alien species is a key issue.…”