LOSS OF PARENTAL CODING SEQUENCES IN AN EARLY GENERATION OF WHEAT-RYE ALLOPOLYPLOID.

During wheat-rye allopolyploidization, the characteristics of the sequences in the bands that appear in both parents and progeny are still unclear. In this study, two different combinations of wheat (Triticum aestivum L.) and rye (Secale cereale L.), including F1 hybrids and the first and second allopolyploid generations, were analyzed by PCR and sequencing using 60 wheat expressed sequence tag (EST)--derived single-sequence repeat markers and EST-derived sequence-tagged site markers. Thirty markers produced the same bands from parental plants, F1 plants, and amphiploids. Seven of the 30 markers amplified identical sequences from wheat and rye parents. Most of these sequences have high similarity between the two parental plants. The variation patterns of sequences in the bands produced by the seven markers were observed. In the F1 hybrids and amphiploids, loss of parental sequences was observed and the frequency of losing rye sequences was higher than that of losing wheat sequences. In addition, a few sequences in these bands exhibited significant differences, indicating that parental sequences changed drastically during allopolyploidization. Therefore, the fact that the parents and progeny contained the same bands should not be regarded as conservation. The results in this study add to the investigations dealing with variation patterns of coding sequences during wheat-rye allopolyploidization. [ABSTRACT FROM AUTHOR]