Factors Associated with Tiller Survival in Sorghum Varieties Resistant to the Sorghum Shoot Fly (Atherigona varia soccata)1
- A. Blum2
Five resistant sorghum (Sorghum sp.) varieties and two susceptible to the sorghum shoot fly (Atherigona varia soccata) were studied in order to evaluate the association between several plant traits and tiller survival after simulated damage in an insectarium and infestation in the field. Under insectarium conditions (non-infested), tillering was simulated through a manual destruction of the growing apex: in seedlings.
The pattern of silica deposition in the abaxial epidermis at the base of the leaf sheaths of tillers differed markedly from that previously reported (3) for seedlings of the same varieties. However, in tillers of resistant varieties, the same lignification was found of the walls of cells which enclose the vascular bundles in the central leaf whorl, as in seedlings of resistant varieties. This was not found in tillers of the susceptible variety. Tillers of all resistant varieties grew faster than those of the susceptible ones. If tillers of resistant varieties were infested, infestation was delayed by two days, as compared with the susceptible one.
The results imply that tiller survival in shoot-fly-resistant sorghum varieties is associated with lignified tissues at the central leaf whorl and a fast growth rate of tillersPlease view the pdf by using the Full Text (PDF) link under 'View' to the left.
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