Four Consistent Loci Confer Adult Plant Resistance to Leaf Rust in the Durum Wheat Lines Heller#1 and Dunkler

Abstract

The durum wheat lines Heller#1 and Dunkler from the International Maize and Wheat Improvement Center Global Wheat Program showed moderate and stable adult plant resistance to leaf rust under high disease pressure over field environments in northwestern Mexico. Leaf rust phenotyping was performed on two recombinant inbred line (RIL) populations derived from crosses of Heller#1 and Dunkler with the susceptible parent Atred#2, conducted under artificially induced Puccinia triticina epidemics in 2013, 2014, 2015, and 2016. The Atred#2 × Heller#1 and Atred#2 × Dunkler populations were genotyped by single nucleotide polymorphism (SNP) platforms and diversity arrays technology markers, respectively. Four leaf rust resistance quantitative trait loci were detected simultaneously in the two RIL populations: Lr46, QLr.cim-2BC, QLr.cim-5BL, and QLr.cim-6BL based on phenotypic data across all four crop seasons. They explained 11.7 to 46.8%, 7.2 to 26.1%, 8.4 to 24.1%, and 12.4 to 28.5%, respectively, of the phenotypic variation for leaf rust resistance in Atred#2 × Heller#1 and 16.3 to 56.6%, 6.7 to 15.7%, 4.1 to 10.1%, and 5.1 to 20.2% of the variation in the Atred#2 × Dunkler population. Only the resistance allele of QLr.cim-2BC was from the susceptible parent Atred#2, and resistance alleles at other loci came from the resistant parents Heller#1 and Dunkler. The SNP markers closely linked to Lr46 and QLr.cim-2BC were converted to kompetitive allele specific PCR markers for use in marker-assisted selection to improve leaf rust resistance through crosses with Heller#1 and Dunkler sources.

Genetics of Resistance to Leaf Rust in Wheat: An Overview in a Genome-Wide Level

“…Two durum wheat lines 'Heller#1 and 'Dunkler' from CIMMYT exhibited moderate and stable APR to leaf rust in the field. Multiple QTLs were detected on chromosomes 1BL (Lr46), 5BL (QLr.cim-5BL) and 6BL (QLr.cim-6BL) from these resistant lines [102]. The AS gene Lr18 was transferred from T. timopheevii to hexaploidy wheat chromosome 5BL [103].…”

Allele Mining and Development of Kompetitive Allele Specific PCR (KASP) Marker in Plant Breeding

“…Wang et al [30] and Muellner et al [63] identified two QTLs associated with dwarf bunt resistance, while Jiang et al [31] discovered the QFhb-5A marker for Fusarium head blight resistance. Additionally, Li et al [32] and Liu et al [33] identified markers associated with leaf rust resistance and stripe rust resistance, respectively. Other studies investigated traits such as grain yield-related traits, green bug resistance, pre-harvest sprouting resistance, kernel weight, wheat curl mite resistance, heat tolerance, and drought tolerance [34][35][36][37][38][39][40].…”

“…Other studies focused on drought and low nitrogen tolerances, bacterial leaf streak resistance, cold tolerance, grain yield and yield components, salt tolerance, brown planthopper resistance, and panicle disease resistance [32,[44][45][46][47][48][49].…”

Genetics of Resistance to Leaf Rust in Wheat: An Overview in A Genome-Wide Level

“…Two durum wheat lines "Heller#1" and "Dunkler" from CIMMYT exerted moderate and stable APR to leaf rust in the field. Multiple QTLs were detected on chromosomes 1BL (Lr46), 5BL (QLr.cim-5BL) and 6BL (QLr.cim-6BL) from these resistant lines [102]. The AS gene Lr18 was transferred from Triticum timopheevii to chromosome 5BL [103].…”