Mm. Rafi et al., FEEDING DAMAGE OF RUSSIAN WHEAT APHID ON RESISTANT AND SUSCEPTIBLE WHEAT GENOTYPES, Cereal Research Communications, 25(1), 1997, pp. 63-68
Effects of Russian wheat aphid (Diuraphis noxia Mordvilko) feeding on
resistant wheat (Triticum aestivum L.) plant introduction line, PI 137
739 (antibiotic line), and a susceptible cultivar, Stephens, were exam
ined. Reduction in leaf chlorophyll content was determined after diffe
rent densities (0, 40 and 80) of aphids were allowed to feed for 3, 6,
9, and 11 days in leaf cages attached to seedlings. In the non-caged
region of infested plants, leaf chlorophyll content was significantly
higher in PI 137739 compared with Stephens. Reduction in chlorophyll c
ontent was not aphid-density or duration of aphid-feeding dependent in
the non-caged regions. In the caged region, increased physical damage
to leaves and significant reduction in total chlorophyll content were
observed in PI 137739 compared with Stephens. Increased aphid density
and prolonged aphid-feeding caused greater reduction in leaf chloroph
yll content in caged sections. Increased probing of aphids because of
restricted movement in the caged section and tissue unpalatibility of
the resistant genotype could have caused severe chlorophyll reduction
in the resistant plant introduction line, PI 137739.