Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/25/2004
Publication Date: 1/1/2005
Citation: Anikster, Y., Manisterski, J., Long, D.L., Leonard, K.J. Leaf rust and stem rust resistance in Triticum dicoccoides populations in Israel. Plant Disease. 89:55-62. Interpretive Summary: Leaf rust is one of the most serious diseases of wheat in the U.S. and worldwide. The most effective and economical way to control leaf rust is through the development of resistant wheat varieties. Unfortunately, most resistance to leaf rust is effective against only some races of the leaf rust fungus. Such resistance usually remains effective for only a few years because new rust races arise that are not affected by the resistance. The available supply of rust resistance genes in cultivated wheat varieties and breeding lines is nearly exhausted. We collected seed from 742 plants of wild emmer wheat from natural habitats in northern Israel and tested the wild emmer lines for resistance to leaf rust in Israel and the U.S. Twenty-one of the lines had resistance in field tests that appeared to be at least moderately effective against all known races of the leaf rust fungus. These lines can be crossed easily to cultivated wheat varieties and may provide combinations of resistance genes with long-lasting protection against leaf rust in U.S. wheat production. This would prevent wheat leaf epidemics that periodically reduce yields by 15% or more in major wheat-producing States in the U.S.
Technical Abstract: A total of 742 single plant accessions of Triticum dicoccoides were collected from 26 locations in Israel. All accessions were evaluated for leaf rust resistance in field plots, and subsets of 284 and 468 accessions were tested in the greenhouse in Tel Aviv and St. Paul, MN, respectively, for seedling resistance to leaf rust; 460 accessions were also tested for seedling resistance to stem rust in St. Paul. One accession was highly resistant to leaf rust in seedling tests in Tel Aviv and 21 others had moderately susceptible to moderately resistant seedling resistance. Four accessions were highly resistant to leaf rust in seedling tests in St. Paul, and 11 were resistant to at least 1 stem rust race. Adult resistance to leaf rust was more common than seedling resistance among the accessions; 21 accessions had less than 25% leaf rust severity in field plots compared to 80-90% severity for highly susceptible accessions. Most of the accessions with effective adult plant resistance came from two nearby locations in Upper Galilee, a region where populations of T. dicoccoides are most extensive and genetically diverse. These accessions may provide valuable new partial resistance genes for durable protection against leaf rust in cultivated wheat.