Sources of stem rust resistance in Ethiopian tetraploid wheat accessions

Abstract

Stem or black rust of wheat caused by the fungus Puccinia graminis f. sp. tritici Ericks and Henn (Pgt) is an important disease on wheat worldwide. Pgt is an obligate biotroph, heteroceous in its life cycle and heterothallic in mating type. Seedlings of 41 emmer (Triticum dicoccum), 56 durum (T. durum) wheat accessions were tested
for their response to stem rust (Puccinia graminis f. sp. trictici) infection under greenhouse condition at Kulumsa Agricultural Research Center, Ethiopia. The test included screening of accessions and multipatotype testing to postulate sr genes. Vigorous screening of accessions was conducted using ten stem rust races, namely TKM/J,
SKM/J, TTM/J, STM/J, TTL/K, TKR/J, TKM/J, TTM/H, SKM/J and JKM/G and, 33 stem rust differential lines. Flor’s gene-for-gene theory was applied to postulate Sr genes in the tested accessions. Eighteen emmer and 6 durum accessions were found to be good sources of resistance to stem rust infection. In addition, the presence of Sr 7b, 8b, 9a, 9b, 10, 14, 24, 27, 28, 29, 30, 31, 32 and Tt-3 + 10 genes was postulated in 16 selected emmer and 5 durum wheat accessions. Hence, efforts to exploit these valuable Sr genes in Ethiopian cultivated tetraploid
wheats could be rewarding to get stem rust resistant varieties and boost wheat production.