Journal of Applied Genetics 49(2), 2008, pp. 141-145

Inheritance of leaf rust resistance in wheat lines carrying Aegilops speltoides Tausch. translocation in Chinese Spring background

Urmil K. Bansal, Ram G. Saini, Renu Khanna

Abstract: The genetic basis of seedling and adult-plant leaf rust resistance was analysed in wheat lines CS 2A/2M 4/2 and CS 2D/2M 3/8, which are reference lines for the leaf rust resistance gene Lr28. Some seedlings of CS 2A/2M 4/2 were susceptible to Indian Puccinia triticina (Pt) pathotypes 77-1, 77-2 and 77-5. These susceptible seedlings exhibited resistance at the adult-plant growth stage. In contrast, CS 2D/2M 3/8 showed resistance to all Pt pathotypes both at the seedling and adult-plant growth stages. The analysis of inheritance in the susceptible plants of CS 2A/2M 4/2 (CS 2A/2M 4/2 APR selection) and CS 2D/2M 3/8 against Pt 77-5 (the frequently occurring Pt pathotype from the Indian subcontinent), indicated that line CS 2D/2M 3/8 was fixed for a dominant gene, presumed to be Lr28, whereas line CS 2A/2M 4/2 was heterogeneous for Lr28. The adult-plant resistance in the CS 2A/2M 4/2 APR selection was conferred by an unknown recessive gene.

Key words: Aegilops comosa, Aegilops speltoides, leaf rust resistance, Puccinia triticina, Triticum aestivum.

Correspondence: U.K. Bansal, Plant Breeding Institute, University of Sydney, Cobbitty, NSW 2570, Australia; e-mail: U.Bansal@usyd.edu.au