Genetic control of crossability of triticale with rye

Limited genetic knowledge is available regarding crossability between hexap loid triticale (2n = 6x = 42, 21 ", AABBRR, amphiploid Triticum turgidum L. -Secale cereale L.) and rye (2n = 14. 7 ", RR). Our objectives were to dete rmine (1) the crossability between triticales and rye and (2) the inheritan ce of crossability between F-2 progeny from intertriticale crosses and rye. First, '8F/Corgo', a hexaploid triticale, was crossed as a female with two landrace ryes, 'Gimonde' and, 'Vila Pouca' and two derived north European cultivars, 'Pluto' and 'Breno'. These crosses produced 21.7, 20.9, 5.9, and 5.6%, seed-set or crossability, respectively, showing that the landrace ry es produced higher seed-set than the cultivars. Second, 'Gimonde' rye was c rossed as a male with four triticales for 3 years. The control cross, 'Chin ese Spring' wheat x rye, produced 80-90% seed-set. Of the four triticales, 'Beagle' produced 35.7-56.8% seed-set. The other three triticales produced less than 20% seed-set, showing that the triticales differ in crossability with 'Gimonde' rye. Third, six F(1)s from intertriticale crosses ('8F/Corgo ' x 'Beagle', 'Beagle' x 'Cachirulo', 'Lasko' x 'Beagle', '8F/Corgo' x 'Cac hirulo', 'Lasko' x 'Cachirulo', 'Lasko' x '8F/Corgo') were crossed to 'Gimo nde' rye. Results indicated that lower crossability trait was partially dom inant in the two F(1)s from crosses involving 'Beagle' (high crossability) with '8F/Corgo' and 'Cachirulo' (low crossability) and completely dominant in the 'Beagle' x 'Lasko' cross, as it happens in wheat. Fourth, segregants in four F-2 populations ('Lasko' x 'Beagle', '8F/Corgo' x 'Beagle', 'Lasko ' x '8F/Corgo', and '8F/Corgo' x 'Cachirulo') were crossed with rye. Segreg ation for crossability was observed, although distinct segregation classes were blurred by environmental and perhaps other factors, such as self-incom patibility alleles in rye. Segregation patterns showed that 'Beagle', with high crossability to rye, carries either Kr1 or Kr2. The three triticales w ith low crossability with rye were most likely homozygous for Kr1 and Kr2. Therefore, it is likely that the Kr loci from A and B genomes acting in whe at also play a role in triticale x rye crosses.