Cytological characteristics of F2 hybrids between Triticum aestivum L. and T. durum Desf. with reference to wheat breeding.

Cytological and agronomic characteristics of a F2 population from Triticum aestivum L. x T. durum Desf. hybrids were analyzed plant by plant. Means of morphologic traits in the F2 population were similar to those of the low-value parent. On average, F2 hybrids had 36.54 chromosomes per plant, indicating that each gamete lost 2.73 chromosomes at meiosis of the F1 generation. More than half of plants had 36-39 chromosomes, so male gametes with 19-21 chromosomes seemed to be superior to the others. The distribution frequency of chromosomes in this study differed from that in a previous report, where a different tetraploid wheat was used. This shows that a different breeding strategy may need to be taken when exploiting a different tetraploid wheat. According to our results, some plants with 42 chromosomes, having all the wheat A, B and D chromosomes, would appear in the F3 population, which provides a chance to obtain stable bread wheat lines from the self-pollinated progenies. Alternatively, the desirable individuals of the F2 population were backcrossed to bread wheat, which is very useful and efficient for the improvement of bread wheat by exploiting desirable genes in durum wheat.