A microsatellite marker linked to leaf rust resistance transferred from Aegilops triuncialis into hexaploid wheat

Abstract

Aegilops triuncialis (UUCC) is an excellent source of resistance to various wheat diseases, including leaf rust. Leaf rust‐resistant derivatives from a cross of a highly susceptible Triticum aestivum cv.‘WL711’ as the recurrent parent and Ae. triuncialis Ace.3549 as the donor and with and without a pair of acrocentric chromosomes were used for molecular tagging. The use of a set of sequence tagged microsatellite (STMS) markers already mapped to different wheat chromosomes unequivocally indicated that STMS marker gwm368 of chromosome 4BS was tightly linked to the Ae. triuncialis leaf rust resistance gene transferred to wheat. The presence of the Ae. Triuncialis‐specific STMS gwm368 homoeoallele along with the non‐polymorphic 4BS allele in the rust‐resistant derivatives with and without the acrocentric chromosome indicates that the resistance has been transferred from the acrocentric chromosome to either the A or the D genome of wheat. This alien leaf rust resistance gene has been temporarily named as LrTr.

A Cryptic Wheat–Aegilops triuncialis Translocation with Leaf Rust Resistance Gene Lr58

“…None of the tested 23 SSRs of chromosomes 5A and 4B identified the A. triuncialis ‐specific introgression in the translocation line TA5605 (data not shown). This suggested that either the leaf rust resistant introgression in TA5605 is different from previous reports of Aghaee‐Sarbarzeh et al (2001, 2002) or the marker density might not be enough to detect the leaf rust resistant introgression of A. triuncialis in TA5605. Bulked segregant analysis of the homozygous resistant and susceptible F 2 bulks was used for chromosome mapping and tagging of the leaf rust resistant introgression using distally mapped RFLP markers.…”

“…The introgression line was developed by crossing the susceptible hexaploid wheat cultivar WL711 with rust‐resistant A. triuncialis (TA10438, PAU no. 3549) and backcrossing the resultant F 1 with WL711 (Harjit‐Singh et al, 2000; Aghaee‐Sarbarzeh et al, 2001). Leaf rust resistant BC 1 F 1 plants were selected, backcrossed further to WL711 and selfed to develop BC 3 F 11 lines.…”

“…Based on previous reports on the association of chromosomes 5A (Aghaee‐Sarbarzeh et al, 2002) and 4B (Aghaee‐Sarbarzeh et al, 2001) with A. triuncialis ‐derived rust resistance, we initially selected nine and 14 SSRs mapping on chromosome 5A and 4B of wheat, respectively, for characterizing the introgression line. Bulk segregant analysis (BSA) with distally mapped restriction fragment length polymorphism (RFLP) markers that detect orthologous alleles among the three genomes was then used to diagnostically identify markers and chromosomes associated with the rust resistance.…”

“…Rust resistance of A. triuncialis also was transferred to wheat without inducing homeologous pairing between chromosomes of wheat and A. triuncialis (Harjit‐Singh et al, 2000; Aghaee‐Sarbarzeh et al, 2001). In one leaf rust resistant line, an introgressed A. triuncialis segment was identified on chromosome arm 4BS (Aghaee‐Sarbarzeh et al, 2001).…”

Genetic diversity of Greek Aegilops species using different types of nuclear genome markers

“…biuncialis, and Ae. speltoides have shown rust resistance (Aghaee-Sarbarzeh et al, 2001;Schneider et al, 2008); Ae. geniculata is resistant to powdery mildew (Stoilova and Spetsov, 2006) and BYDV (Barley Yellow Dwarf Virus) (Zaharieva et al, 2001b); Ae.…”