Changes in Frequency of Plants Resistant to Barley Leaf Rust Caused byPuccinia hordeiOtth. in a Barley Composite Cross Population

摘要

AbstractThe response of barley Composite Cross XLI to selection for resistance to leaf rust was evaluated. Representative samples from eight cycles of recurrent selection were inoculated with an isolate ofPuccinia bordeiOtth. in both the seedling and adult plant stage. Disease symptoms were evaluated 14 days after inoculation. The resistance in CC XLI increased with selection in the seedling stage from 15.1 to 20.5 , and in the adult plant stage from 20.5 to 37.5 , respectively. The largest gains in resistance were observed in the earlier cycles of recurrent selection. Significant fluctuations in percent resistant plants occurred between the years.