Ethiopian barley landraces: useful resistant sources to manage Barley yellow dwarf and other foliar diseases constraining productivity
One hundred sixty-five advanced lines were subjected to marker-assisted selection using Cleaved amplified polymorphic sequence-polymerase chain reaction (CAPS-PCR) primer against Barley yellow dwarf (BYD) resistant Yd2 gene. In addition, phenotypic evaluation was employed to screen the advanced lines for multiple disease resistance. Effect of host growth rate and incubation period on BYD development was also assessed. Results of marker PCR showed that Yd2 gene was detected in 96 (58.2%) out of 165 accessions tested. Data on relationships of days to heading (DtH) and BYD symptoms development revealed that barley accessions having shorter DtH (66 days), BYD severity appeared low, and vice versa on accessions having longer DtH (79–83 days). Screening for multiple disease resistance gave interesting results. Among 11 accessions (with Yd2) selected as the best for multiple diseases, 6 accessions [Chelia local, 4304–2(2), 4818(1.3), 1822–1(1), 1831–2-2(2), and 4915–1(1.2)] were highly resistant to leaf rust and net blotch, while other five lines had moderately resistant reaction. Study on the relationship of host resistance and incubation period showed that BYDV was detectable 5 days earlier in susceptible than in resistant lines. This can be used as an alternative method in preliminary screening of large number of genotypes against BYDV. From this study, it was evident that the identified resistant genotypes are a good resource for barley improvement program targeting BYDV and other important foliar pathogens. Barley breeders are encouraged to take advantage of this opportunity in producing multi-disease resistant barley genotypes in an agronomically enhanced genetic background in the country and beyond.