Identification of Leaf Rust Resistance Genes in Egyptian Wheat Cultivars by Multipathotypes and Molecular Markers

Abstract

A total of twenty leaf rust resistance genes (Lr genes) were postulated in nine Egyptian wheat cultivars based on infection types (ITs) expressed on the tested cultivars by 72 Puccinia triticina pathotypes compared with the ITs expressed on the monogenic lines. The most carrier genes cultivars were Giza168 and Misr1 each may contain five genes i.e. Lr2c,10,18,24, 41 and Lr3,10,19, 22b,24, respectively. Five cultivars, Sakha94, Gemmeiza9, Gemmeiza10, Sids12 and Misr2 each probably contain four genes i.e. Lr9,19,29, 37; Lr18,21,24, 41; Lr3,9,19,29; Lr9,19,26, 29 and Lr3,10,19,26, respectively. Gemmeiza11 was the least cultivar carrying genes; it probably carries just two genes i.e. Lr24 and Lr41. The most postulated genes were Lr19 and Lr24, each postulated within five cultivars followed by Lr41 within four cultivars. Five Lr genes, Lr3, Lr9, Lr10, Lr26 and Lr29 each within three cultivars. The lowest postulated genes were Lr2c, Lr21, Lr22b and Lr37 each of them was postulated within only one cultivar. Five Lr genes, Lr9, Lr10, Lr19, Lr24 and Lr26 were identified by PCR-based molecular marker. The Lr9 gene was identified in cultivar Sids12 while, Lr10 was identified in cultivar Misr1. The Lr19 was present in two cultivars, Misr1 and Misr2. The Lr24 and Lr26 were absent in all the screened Egyptian cultivars. The obtained results for Lr9, Lr10, Lr19, Lr24 and Lr26 marker were in agreement with and confirm their identification by gene postulation. Markers for Lr9, Lr10 and Lr19 may be useful in marker-assisted breeding. Our findings showed the usefulness of the molecular marker in identifying leaf rust resistance genes in wheat cultivars, especially when used in conjunction with multipathotypes test at the pre-breeding stage. This approach may help understanding the wheat -P. triticina interaction and provide information to build an effective management program for leaf rust disease.