Plant Genome III Conference

RFLP MAPPING OF GENES ASSOCIATED WITH DIFFERENT AGRONOMIC TRAITS AND DISEASE RESISTANCE IN WHEAT

1. International Maize & Wheat Improvement Center (CIMMYT)
2. Dept. of Plant Breeding and Biometry, Cornell University

A single-seed-descent F7 population of 114 lines was developed from a cross between a synthetic hexaploid wheat (Altar 84/ T. tauschii) and T. aestivum cultivar Opata 85. This population was used to construct a wheat RFLP map and evaluated in northwestern Mexico for yield, yield components and certain agronomic traits. Lines were classified for their seedling and field responses to leaf rust, stripe rust and Kamal bunt diseases. Days to heading was associated with chromosomal regions in 2DS, 5AL and 5DL corresponding respectively to photoperiod- sensitivity gene Ppdl and vernalization genes Vrnl and Vrn3. Yield under full and reduced irrigation and some yield components were associated with markers close to the photoperiod gene as well as several in other chromosomal regions. Adult-plant resistance to leaf and stripe rust was strongly associated with markers in the distal portion of chromosome arm 7DS where genes Lr34 and Yr18 are located. Additional regions associated with seedling and adult-plant rust resistance were also detected. Resistance to Kamal bunt was associated with four chromosomal regions. Our results indicate that this population is useful for mapping genes controlling many traits.