Improved Disease Resistance in barley against powdery mildew, cover smut and stripe disease.

 M.A. AL-Hamdany, J. A. sabar and A.H. Kadhem.

Citation: 2000. Iraqi J. Agric., 5 (3): 8-18.

Abstract:

     High levels of crop improvement for disease resistance against powdery mildew, covered smut and stripe disease in barley were successfully achieved by genetic means. Breeding program for disease resistance in barley has been initiated based on the identification of resistance sources and utilization of these sources in the program. Mildew highly resistant source (H-421) was identified. The resistance was conditioned by Mla13 with a complete dominancy. Another source of resistance to both stripe disease and covered smut (Strain Aimer) was designated. The well known barley cultivar (Numar) was used because of its susceptible reaction to the three diseases. Crosses between Numar and H-421 along with a series of back crosses (BC1-BC3) were carried out. All the progenies were continuously screened for mildew resistance under artificial inoculation. Results concerning the multiple disease resistance against mildew, stripe disease and covered smut were successfully reflected in developing five barley strains (IR8, IR11, IR18, IR21, and IR28) having naked seeds and highly resistance to the three diseases (no infection at all in powdery mildew and stripe disease and low level of infection (0-5%) with covered smut). These strains were introduced in comparison tests for yield components under artificial inoculations of the three diseases in two consecutive seasons. Results indicated that two strains namely IR21 and IR28 were chosen. In contrary to cultivar Numar, the productivity of these resistant strains was not affected in spite of the artificial inoculations.                                                                                           

Key words: Barley, Breeding for multiple disease resistance, powdery mildew, covered smut, stripe disease, Mla13, sources of resistance