Abstract
Recently, leaf rust and yellow rust caused by the fungi Puccinia triticina Erikss. and P. striiformis Westend f. sp. tritici Eriks and Henn are diseases of increasing threat in triticale (× Triticosecale Wittmack, AABBRR, 2n = 6x = 42) growing areas. The use of genetic resistance is considered the most economical, effective and environmentally friendly method to control the disease and minimize the use of fungicides. Currently, breeding programs mainly relied on race-specific Lr and Yr genes (R), but new races of the rust fungi frequently defeat resistance. There is a small group of genes that causes partial type of resistance (PR) that are characterized by a slow epidemic build up despite a high infection type. In wheat slow rusting resistance genes displayed longer latent periods, low infection frequencies, smaller pustule size and less spore production. Slow rusting Lr46/Yr29 gene, located on chromosome 1B, is being exploited in many wheat breeding programs. So far, there is no information about slow rusting genes in triticale. This paper showed significant differences between the results of identification of wheat molecular markers Xwmc44 and csLV46G22 associated with Lr46/Yr29 in twenty triticale cultivars, which were characterized by high levels of field resistance to leaf and yellow rust. The csLV46G22res marker has been identified in the following cultivars: Kasyno, Mamut and Puzon. Belcanto and Kasyno showed the highest resistance levels in three-year (2016–2018), leaf and yellow rust severity tests under post-registration variety testing program (PDO). Leaf tip necrosis, a phenotypic trait associated with Lr34/Yr18 and Lr46/Yr29 was observed, among others, to Belcanto and Kasyno, which showed the highest resistance for leaf rust and yellow rust. Kasyno could be considered to have Lr46/Yr29 and can be used as a source of slow rust resistance in breeding and importantly as a component of gene pyramiding in triticale.
Highlights
Triticale (× Triticosecale Wittmack, 2n = 6x = 42, AABBRR genomes) is a man-made amphiploid hybrid produced from the crossing of female parent hexaploid or tetraploid wheat (Triticum sp.) and male parent rye (Secale cereale L.) (Ammar et al 2004)
This paper showed significant differences between the results of identification of wheat molecular markers Xwmc44 and csLV46G22 associated with Lr46/Yr29 in twenty triticale cultivars, which were characterized by high levels of field resistance to leaf and yellow rust
A phenotypic trait associated with Lr34/Yr18 and Lr46/Yr29 was observed, among others, to Belcanto and Kasyno, which showed the highest resistance for leaf rust and yellow rust
Summary
Lr46/Yr29 has provided partial APR to leaf and stripe rust for more than 60 years (Kolmer et al 2015) It was first described in cultivar Pavon 76 and located on long arm of chromosome 1B (Singh et al 1998). Wheat genotypes with gene Lr46/Yr29 were determined to have stem rust Sr58 resistance gene (Singh et al 2013) and powdery mildew (Pm39) resistance gene (Lillemo et al 2008) Both genes (Lr34/Yr18 and Lr46/Yr29) are associated with a specific phenotypic trait, leaf tip necrosis (LTN) (Singh 1992; Rosewarne et al 2006). Other slow rusting genes—Lr34/Yr18, Lr67/Yr46 and Lr78 are located on the D genome (7DS, 4DL and 5DS, respectively), which is not present in the triticale genotype It is entirely possible, that wheat donors of Lr46/Yr29 gene were used in triticale breeding programs. Two closest markers (Xwmc and csLV46G22) linked to Lr46/Yr29 were chosen in this study to postulate the presence of Lr46/Yr29 gene in fourteen winter and six spring Polish cultivars of triticale
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
