|Rotich, Felix - University Of Arkansas|
|Feng, Chunda - University Of Arkansas|
|Groth, Don - Louisiana State University|
|Correll, James - University Of Arkansas|
Submitted to: Arkansas Agricultural Experiment Station Research Series
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2014
Publication Date: 8/1/2014
Citation: Rotich, F., Feng, C., Jia, Y., Groth, D., Correll, J. 2014. Characterizing virulence phenotypes among U.S. isolates of Magnaporthe oryzae using IRRI NILs, US germplasm, and NERICA lines. In BR Wells Studies- series 609 2013. Edited by Norman, RJ., Molderhauer, KAK, University of Arkansas. Pages 109-115.
Technical Abstract: Rice blast disease, caused by Magnaporthe oryzae, is a major constraint to rice production in most rice production areas, including the Southern U.S. In continued efforts to evaluate the effectiveness of resistance (R) genes, a total of 33 field and 12 U.S. reference isolates of M. oryzae were evaluated for virulence using two sets of differentials developed by the International Rice Research Institute (IRRI). The first of differentials comprised 31 monogenic lines with 24 R genes and, the second set included 20 lines with 14 R genes. In addition, four Nerica lines (New Rice for Africa, NERICA lines)) and five U.S. rice cultivars were evaluated. The two sets of IRRI differential lines discriminated isolates into diverse virulence phenotype groups. The cultivars Lijiangxintuanheigu (LTH) and CO39, the background cultivars in the development of the IRRI differentials, had R genes effective against some of the isolates. NERICA 5 was resistant to all the isolates evaluated while the other three NERICA lines (NERICA 2, NERICA 12, and NERICA 15) were also highly resistant. Thus, the R genes in the NERICA lines could be exploited as potential new sources of resistance to rice blast in the U.S. rice lines. The U.S. cultivars Jumildhan and UZR275 were the most susceptible lines tested with each cultivar being susceptible to all of the isolates tested. The sets of IRRI differential lines were useful in discriminating virulence virulence phenotypes among U.S. rice blast pathogen isolates. Future efforts continue to focus on phenotyping additional field isolates to fully evaluate the effectiveness of specific resistance genes.