Alien Introgression in Wheat Cytogenetics, Molecular Biology, and Genomics

© Springer International Publishing Switzerland 2015 103
M. Molnár-Láng et al. (eds.), Alien Introgression in Wheat,
DOI 10.1007/978-3-319-23494-6_4

Chapter 4

The Crossability of Wheat with Rye

and Other Related Species

Márta Molnár-Láng

4.1 Gen etic Control of the Crossability of Wheat with Rye

Varieties of common wheat, Triticum aestivum L. (2 n = 6× = 42), differ in the ease
with which they hybridize with rye, Secale cereale L. (2 n = 14). Following emascu-
lation and hand pollination, more than 50 % of the pollinated fl orets usually set
seeds in readily crossable varieties. By contrast less than 5 % of fl orets set seeds in
poorly crossable forms (Riley and Chapman 1967 ).
The fi rst detailed analys is of crossability was carried out by Lein ( 1943 ), using the
readily crossable wheat variety Chinese 466 and the poorly crossable varieties
Marquis and Peragis. Ready crossability is recessive an d, by pollinating F 2 plants
from intervarietal crosses with rye, Lein showed that allelic differences at two loci
were responsible for the contrasting parental behavior. On this basis it was suggested
that Chinese 466 was genotypically kr1kr1kr2kr2 , while Marquis and Peragis were
Kr1Kr1Kr2Kr2. Moreover, the variety Blausamtiger Kolben, which had an interme-
diate level of crossability and which was also included in the analysis, was thought to
be genotypically Kr1Kr1kr2kr2. Lein concluded from these results that the presence
of Kr1 resulted in a more marked reduction in crossability than the presence of Kr2.
According to Lein’s classifi cation ( 1943 ) the relationship between genotype ( kr
allele composition) and phenotype (percentage of crossability with rye) is the
following:

Genotype Percentage crossability with rye

Kr1Kr1Kr2Kr2 <5

Kr1Kr1kr2kr2 10–30

M. Molnár-Láng (*)
Agricultural Institute, Centre for Agricultural Research , Hungarian Academy of Sciences ,
19 , Martonvásár 2462 , Hungary
e-mail: [email protected]