New Zealand Plant Protection 63 (2010): 271
Neck rot, caused by Botrytis allii, is an important storage disease of onions. Fungicides, including benzimidazoles, have been used as seed treatments and crop applications to control this disease during seed and bulb production. Resistance to benzimidazole fungicides has been previously reported in B. allii from New Zealand. Five sensitive and five resistant isolates of the pathogen were grown in culture for DNA extraction and analysis of sequences of β-tubulin fragments. Sequence analysis revealed a single point mutation in the β-tubulin gene in the resistant isolates. PCR primers to detect the mutation were designed and tested, and these clearly differentiated resistant from sensitive isolates. The PCR test developed in this study will allow rapid and cost-effective screening of B. allii isolates to determine their sensitivity to benzimidazole fungicides. The test provides technology that will assist in the development of fungicide resistance management tools for onion crops.
Copyright © 2010 New Zealand Plant Protection Society (Inc.).