Attempts to Improve the Method for Screening Cowpea Germplasm for Resistance to Cucumber Mosaic Virus and Blackeye Cowpea Mosaic Virus

摘要

Use of visual symptom screening of cowpea plants in field plots improved screening for Blackeye Cowpea Mosaic Virus (BlCMV)-resistance. However, the method failed to improve the speed or accuracy of screening for Cucumber Mosaic Virus (CMV)-resistance. Plants that displayed few visual virus symptoms were selected for screening by a previously published method. This method involved screening by mechanical virus inoculation in the greenhouse. Plants having a low infection percentage in the greenhouse as judged by Direct-Antigen Coating Enzyme-linked Immunosorbent Assay (DAC-ELISA) were then screened in the field by randomized virus spread tests from inoculated spreader rows. Infection rates in these tests were also determined by DAC-ELISA. The test resulted in the detection of eleven newly discovered sources of resistance to B1CMV, but no significant new sources of CMV-resistance were found.