© Springer International Publishing Switzerland 2015 163
M. Molnár-Láng et al. (eds.), Alien Introgression in Wheat,
DOI 10.1007/978-3-319-23494-6_7
Chapter 7
Introgressions Between Wheat and Rye
Adam J. Lukaszewski
7.1 Introduction
Rye is a distant relative of wheat ; it is estimated that the spilt from the common
ancestor took place about 3.5 million years ago (Middleton et al. 2014 ). Within the
genus Secale, S. cereale , or common rye, is the only widely cultivated species,
especially in Central and Northern Europe where it is the crop of choice for light
soils. It is valued for its hardiness and tolerance to many biotic and abiotic stresses.
While its general quality/utility is nowhere near to that of wheat, it can be reliably
grown on much more demanding soils and in harsher environments. As such, it has
always been viewed with much envy by wheat breeders and many efforts have been
made to utilize its gene pool for wheat improvement. Perhaps the most comprehen-
sive of these efforts is the creation of triticale, a man-made amphiploid combining
entire genomes of diploid rye and either two (AB) or three (ABD) genomes of
hexaploid wheat. Tetraploid triticales, combining one genome each of wheat and
rye, and produced in several different ways, have been created in several places but
do not appear to offer a perspective as a crop. Of the three ploidy levels, hexaploid
triticale, genomes AABBRR with possible modifi cations, is successful, with yields
often exceeding wheat, at least o n lands marginal for wheat ; production. It is an
excellent feed crop with several still unresolved issues in the context of human
consumption.
This chapter, however, does not deal with issues of introgressions of entire
genome s, and hence, triticale is beyond its scope. The chapter deals with introgres-
sions on a sub-genome scale, such as chromosomes and chromosome segments.
The author does not have the ambition of presenting a comprehensive literature
review on the topic but rather to present and discuss general concepts and the state
A. J. Lukaszewski (*)
University of California , Riverside , CA , USA
e-mail: [email protected]