Resistance to Leaf Rust, Stripe Rust, and Stem Rust in Aegilops spp. in Israel

Area of Science:

• Plant Pathology
• Agronomy
• Genetics

Background:

• Wheat rust diseases, including leaf rust (Puccinia triticina), stripe rust (P. striiformis), and stem rust (P. graminis f. sp. tritici), pose significant threats to global food security.
• Wild relatives of wheat, such as Aegilops species, are valuable genetic resources for introducing novel resistance genes into cultivated wheat.
• The Near East, particularly Israel and surrounding regions, harbors a diverse collection of Aegilops species with potential for disease resistance.

Purpose of the Study:

• To evaluate the rust resistance of 1,323 Aegilops accessions collected from Israel, Lebanon, and Egypt.
• To identify specific Aegilops species and accessions exhibiting high levels of resistance to key wheat rust pathogens.
• To assess the potential of these wild relatives as sources of rust resistance for wheat breeding programs.

Main Methods:

• Field evaluations of 1,323 Aegilops accessions for resistance to leaf rust and stripe rust.
• Greenhouse screening of accessions for seedling resistance to leaf rust and stem rust.
• Pathogen inoculation using Puccinia triticina, P. striiformis, and P. graminis f. sp. tritici.

Main Results:

• Aegilops speltoides accessions demonstrated high resistance to leaf, stripe, and stem rusts.
• Aegilops longissima and A. ovata showed high resistance to stripe rust, while A. bicornis and A. kotschyi were susceptible.
• Varied stem rust resistance was observed, with 24-51% of accessions of A. bicornis, A. longissima, A. ovata, and A. variabilis being resistant.
• Most Aegilops accessions (except A. ovata and A. speltoides) were susceptible to leaf rust caused by P. recondita.
• A. bicornis, A. kotschyi, and A. searsii were susceptible to common wheat leaf rust (P. triticina) seedlings, while A. variabilis and some A. longissima accessions showed resistance.
• Adult plants of most Aegilops species (except A. bicornis) showed low levels of leaf rust in field tests.

Conclusions:

• The evaluated Aegilops species represent a rich source of diverse rust resistance traits.
• Aegilops speltoides, A. longissima, and A. ovata are particularly promising for breeding rust-resistant wheat varieties.
• Further research and utilization of these wild relatives can significantly contribute to developing durable rust resistance in wheat.