Author
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Goates, Blair |
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Submitted to: Phytopathology
Publication Type: Abstract Only Publication Acceptance Date: 4/30/2008 Publication Date: 6/1/2008 Citation: Goates, B. 2008. Quantification of Tilletia indica teliospores in sori of commercially harvested wheat grains. Phytopathology 98 (6):S60 Interpretive Summary: Technical Abstract: Karnal bunt caused by Tilletia indica is a minor disease of wheat that has caused considerable international quarantine concerns. Knowledge of the number of teliospores in sori of diseased grains is needed to provide information for the development of pest risk assessments. Eight to fourteen diseased kernels were randomly selected from each of nine diverse commercially harvested wheat samples collected during three seasons. Diseased kernels were soaked individually in 0.5% Tween for 1-2 d and then spores were carefully dissected from kernels and suspended in Tween for 1-2 d. The suspensions were vigorously vortexed for 1 minute and three, 10 µl aliquots were removed from 10 to 40 ml of total suspension for spore counts. Counts from each aliquot were similar. Mean spore counts per kernel among samples ranged from 1.2x104 to 3.8x104. Spore counts per kernel among all kernels examined ranged from 1.0x103 to 9.3x104; mean 2.3x104. Six kernels with intact point infections selected from the commercial grain samples had from 1.9x104 to 8.9x104 spores; mean 4.7x104. Spore counts from four artificially inoculated, extremely infected hand-threshed kernels with intact sori ranged from 2.6x105 to 5.0x105; mean 3.8x105. Such fragile kernels are normally not found intact in commercial grain. This information enables more precise estimations of teliospore numbers in infected grains which will improve the accuracy of pest risk assessments. |
