Necrotic incompatibility in hexaploid bread wheat and synthetic wheats with Triticum tauschii   genes crosses

With the aim to increase genetic variability and resistance to Puccinia striiformis of wheat germplasm in the Wheat Breeding Program of the Instituto de Investigaciones Agropecuarias, Centro Regional de Investigación Quilamapu, Chillán, Chile, 278 artificial crosses were made between hexaploid bread wheats and synthetic wheats with Triticum tauschii genes. Crosses were carried out under field conditions during 1997- 1998 season. Of total F1 hybrids, 190 were normal in growing and development, and the remaining 88 showed necrotic incompatibility, which was expressed as dead plants at begining of the emergence; plants that growed up to the flag leaf stage and then died, and very late plants with slow growth and leaves forming a compact bunch shape. These plants died before reaching their reproductive stage. Fifty percent of F1 hybrid viables was susceptible to Puccinia striiformis