110
as indicated by crosses involving China 3 and Pau 45 (Falk and Kasha 1981 ). Zeven
( 1987 ) investigated the geographic distribution of kr alleles on crossability data for
1400 wheat genotypes and con cluded that kr alleles occur with high frequency in
bread wheat landraces from China, Japan, East Siberia, and Iran. However not all
varieties from these countries have high crossability, as indicated by the Chinese
varieties listed among the 1400 cultivars in this publication.
West European wheat cultivars generally have poor crossability with rye
(Stefanowska and Cauderon 1983 ). The hexaploid wheat cultivar Roazon, which is
agronomically similar to intensive West European common wheats was derived
from interspecifi c hybridization involving three different species and retained the
Aegilops ventricosa cytoplasm. It was shown that Roazon, unlike West European
wheat s, had good crossability with rye cv. P etkus (Stefanowska and Cauderon
1983 ). According to these authors Roazon has a kr1kr1Kr2Kr2 genotype.
Chinese wheat ( Triticum aestivum L.) landraces originating in the Sichuan Basin
were tested for crossability with rye by Luo et al. ( 1992 ). Sichuan province, which
lies in the southwest of China, consists of the Sichuan Basin and the adjacent moun-
tain ranges. Only spring wheats are grown in this region, which is where Chinese
Spring originates from. Four groups could be distinguished among the 177 geno-
types. The 68 landraces in the fi rst group showed low crossability with rye, with
seed set percentages less than 5 %. The 59 landraces in the second group could be
crossed with rye, having crossability percentages greater than or equal to 5 %, but
signifi cantly lower than that of Chinese Spring. The 34 landraces in group III had
similar crossability to Chinese Spring. The 16 landraces in group IV crossed very
easily with rye, and had crossability percentages signifi cantly higher than that of
Chinese Spring. Most landraces with high crossability occurred in the Qinling and
Dabashan mountain ranges in the north of Sichuan and in the valleys of the rivers
Minjiang, Fujiang and Jialinjiang in the Sichuan Basin. Seventy-two wheat landra-
ces originating from Shaanxi province and 46 landraces from Henan province in
China were pollinated with rye to observe their crossability with rye by Luo et al.
( 1993 ). Seven of the 72 landraces from Shaanxi expressed a much higher crossabil-
ity level than Chinese Spring. As to the geographical distribution landraces with
high crossability percentages were mainly distributed in the valley of the River
Weihe in central Shaanxi, in the Hanzhong Plain and in the hilly area along the
Qinling and Dabashan mountains. Seven of the 46 samples from Henan province
were very easy to cross with rye. Landraces with crossability similar to o r signifi -
cantly higher than Chinese Spring mainly occurred in the west and southwest parts
of Henan province, showing a geographically continuous distribution with those in
Shaanxi. The studies of Luo et al. ( 1992 , 1993 ) revealed that highly crossable land-
races occur in the Sichuan, Shaanxi and Henan provinces of China, and have cross-
ability similar to or even higher than that of Chinese Spring. These landraces carry
recessive kr4 genes (Zheng et al. 1992 ; Luo et al. 1993 ). The crossability of landra-
ces from India and of improved semi-dwarf, high-yielding Indian wheat cultivars
adapted locally was investig ated by Sarvjeet Singh and Sethi ( 1991 ). Sixty-two
bread wheat accessions (19 landraces, 43 others) representing local wheat germ-
plasm from the Himalayan ranges were pollinated with rye. Two of the 14 landraces
M. Molnár-Láng