BREEDING TECHNOLOGY OF ALLOPLASMIC WHEAT

Novel wheat bearing alloplasm was bred via nucleo substitution backcro ss. Through comparative study between the homonucleo-heterocytoplasmic lines and homocytoplasm-heteronuclear lines, it was shown that a port ion of the alloplasm types were able to produce useful genetic effects on wheat yield, grain quality, tolerance of salt and resistance to di seases. Among the species studied, the cytoplasm of Aegilops crassa, A e. squarrosa and Ae. ventricosa contributed the best effect. Specific combination of nuclear genes and cytoplasmic genes conferred specific characteristics and degree of nucleoplasmic heterosis. The alloplasmic wheat lines with cytoplasm substituted were successfully bred with go od quality and resistance to disease and harsh conditions. In particul ar, the new variety of nucleoplasmic hybrid having Ae. crassa cytoplas m proved the best in production lest, demonstration and regional test and was consequently pre-approved for large-scale plantation. The prob ing of the genetic variations and the utilization of alloplasmic wheat was proven to be valuable for both genetic study and breeding of new varieties.