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Intergeneric and interspecific crosses were made among Pseudoroegneria cognata (Hackel) A. Love (2n=14, SS), Elymus semicostatus (Nees ex Steud.) Melderis (2n=4x=28, SSYY) and E. pendulinirs (Nevski) Tzvelev (2n=4x=28, SSYY), collected in Pakistan and China. Chromosome pairing and numerical analysis of meioses were studied in the hybrids. Meiotic configurations of all triploid hybrids fit a 2:l model with X-values ranging from 0.924 to 0.979, and those of tetraploid combinations fall into a 22 model with X-values ranging from 0.883 to 0.939. It is concluded from the study that (i) the “S” genome in P. cognata is more closely related to E. semicostatus than to that in E. pendulinus; (ii) the “SSYY” genomes of E. semicostatus and E. pendulinus are slightly differentiated from one another; and (iii) a certain degree of homoeology exists between “S” and “Y” genomes of the species studied. |
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