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. × 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.