Genetic Variation for Resistance to Russian Wheat Aphid in F2-Derived Families of Wheat (Triticum aestivum L.).

The russian wheat aphid (rwa), diuraphis noxia (mordvilko), is a significant insect pest of wheat worldwide. the objective of this study was to assess the genetic variation within and between f2-derived families for reaction to rwa using f3 and f4 families originating from individual f2 plants of a cross between the susceptible line (synthetic hexaploid-11) and the resistance cultivar ('halt'). the rwa damage of individual plants within each family was measured using different procedures. their reaction types were combined into a single data for each individual family (derived from an individual f2 plants) and subjected to statistical analysis. results indicated that the genetic variation between f2-derived families is greater than within f2-derived families for rwa resistance. broad-sense heritability of rwa resistance, calculated by partitioning phenotypic variation into genetic and environmental components, was 73.2%. a narrow-sense heritability estimate of 30% was obtained for the rwa resistance in the 'halt' synthetic hexaploid-11 cross using parent-offspring (f3: f4) regression procedure.