Use of PCR Markers to Select Barley Yellow Dwarf Virus Resistant Plants

摘要

Barley yellow dwarf virus (BYDV) is considered the most economically important virus affecting cereal crops worldwide. The use of laboratory methods to identify plants resistant to BYDV at the seedling stage could make the selection of resistant plants in the F2 population simple and fast. By using tissue-blot immunoassay (TBIA) to monitor BYDV concentration in the parents and F2populations of 21 barley crosses planted in pots in a plastic house, it zvas possible to identify resistant plants based onthe absence of virus in phloem tissues five days after i7ioculation. Such differentiation was less clear when the test was conducted nine days after virus inoculation, and was not possible 14 days after virus inoculation. Using this approach, it was possible to eliminate susceptible plants five days after inoculation and transplant the resistant ones to the field for observation until harvest. When a similar study was conducted on the parents and the F2 popidations of 26 crosses planted directly in thefield, it was possible to differentiate resistant plants three weeks after virus inoculation. Planting directly in the field avoids the need for transplanting, which promotes better plant development. However, preliminary screening in the plastic houserequires much less space compared to direct planting in the field. Within the same crosses and popidations, the usefulness of the Yd2 specific PCR primers was tested. The availability of aUele-specific or cleaved amplified polymorphic sequence PCR markers makes it possible to quickly identify the presence of the Yd2 gene in the barley material and compare its presence with the expression of resistance in the field. In most cases analyzed, the Yd2 gene was found to be present in BYDV resistant plajits. The use of virus movement and PCR markers proved to be useful in selecting barley genotypes resistant to BYDV at the seedling stage.