Increasing the Genetic Variation of Wheat Germplasm by Introgressing Thinopyrum intermedium Chromosomes and Chromosome Segments

Wheat (Triticum aestivum L., ABD, 2n=6x=42) is one of the most important food crops in the world. In the next forty years, world food production will face an increase in food demand of 70% caused by the growth of the current world population from 6.7 billion to 9 billion. One of the challenges to today’s agricultural research is thus to develop new high-yielding wheat cultivars adaptable to a range of climate changes in a sustainable manner.

The transfer of the genetic diversity from wild species provides an important strategy by which wheat can be adapted to the changing environment. Intermediate wheatgrass (Thinopyrum intermedium, Barkworth & D.R. Dewey, JJ^sS, 2n=6x=42) is one of the most promising gene sources within the Triticeae. Its main advantages consist of resistance to various diseases (leaf rust, wheat streak mosaic virus, etc.), tolerance to abiotic stresses (drought, high temperature, salinity) and perennial growth habit.

The aim of the present work is to develop a new original strategy to exploit the full potential of the wheatgrass genome in wheat improvement by inducing genome wide introgressions in wheat-Th. intermedium hybrids and derivatives. Selection procedures are being facilitated by the use of an Axiom 35k (Affymetrix) exome capture based SNP array. From the 2187 polymorphic SNPs identified 343 were mapped on a preliminary genetic map composed of 125 BC₁, BC₂ and BC₃plants. To support the SNP data analysis the presence of the wheatgrass introgressions have been confirmed by molecular cytogenetic techniques, i.e. GISH and FISH.

AC gratefully acknowledges support from a Marie Curie Fellowship Grant (FP7-PEOPLE-2013-IEF-625671) under the seventh framework program of the European Union. This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) (Grant BB/100260X/1; “Enhancing diversity in UK wheat through a public sector prebreeding programme”).