90
barriers, the introduction of many deleterious genes linked with one useful gene,
etc. The fi rst results published by Lusser et al. ( 2011 ) were achieved for potato
and apple.
The prospects and opportunities opened up by developments in crop genomics
must be translated into outcomes that improve agricultural productivity and sustain-
ability in the future. Genomic selection is a promising new tool for estimating
breeding value, which will contribute to the improvement of the quantitative char-
acters that are controlled by many loci with small effects by means of genome-wide
marker coverage (Heffner et al. 2009 ).
3.4.4 Alien Gene Introgressions in Wheat Germplasm
In the last century, the introgression of the genes or gene complexes responsible for
the favourable properties of rye into wheat proved to be one of the most effective
ways of enhancing the adaptability and grain yield of wheat. It has long been the
desire of wheat breeders to combine the high level of adaptability to extensive con-
ditions, winter hardiness, earliness and tillering ability of rye with the good quality
of wheat. Many breeders in various countries have attempted to develop wheat × rye
hybrids, primarily with the aim of transferring the disease resistance and winter
hardiness of rye into wheat. The year 1917 played an important role in the theoreti-
cal work of the Russian scientist Vavilov (Szunics, personal communication),
because the hot dry weather caused rye and wheat to fl ower at the same time, lead-
ing to a considerable extent of cross-pollination and natural hybridisation and
allowing Vavilov to collect large quantities of wheat × rye hybrid seed. The 1RS.1BL
translocations developed by Riebesel and Katterman in Germany in the 1920s and
1930s were of great signifi cance. In 1964 Tsunewaki crossed two octoploid tritica-
les to develop the Salmon wheat cultivar, which, according to Zeller ( 1973 ), con-
tains a translocation homologous to that in Salzmunder 14–14 and Zorba. The
1RS.1AL translocation was introduced into the American cultivar Amigo via the
Argentine diploid rye , Insave F.A.
The 1RS.1BL wheat-rye translocations , the 1B(R) substitution and the 1RS.1AL
translocations contributed to improvements in the yield potential, adaptability, dis-
ease resistance and insect resistance of wheat. Since then the occurrence of the
1RS.1BL translocation has been reported in more than 1000 wheat cultivars (Zeller
1972 ; Mettin et al. 1973 ; Schlegel and Korzun 1997 ; Lukaszewski 1990 ; Rabinovich
1998 ). A gene complex that includes the resistance genes Sr31 for stem rust
( Puccinia graminis ), Lr26 for leaf rust ( P. recondita ), Yr9 for yellow rust ( P. striifor-
mis ), Pm8 for powdery mildew ( Erisiphe graminis ) and Gb for leaf aphids ( Schizapis
graminum ) is now to be found in a large proportion of the cultivars currently grown
(Heun and Fischbeck 1987 ; Sebesta et al. 1995 ). Although the gene complex has
now lost its resistance to powdery mildew and leaf rust, it still protects wheat from
many stem rust races, with the exception of Ug99. Some 11–12 % of the increase in
the biological yield of wheat can be attributed to the 1RS.1BL rye translocation
Z. Bedő and L. Láng