Allelic variants for Waxy genes in common wheat lines bred at the Lukyanenko National Grain Center

This article presents the results of a molecular marker-assisted study of allelic variants of Wx genes in common wheat (Triticum aestivum L.) lines. The study was carried out as part of the work on the transfer of null alleles of the genes Wx-A1, Wx-B1, and Wx-D1 to the varieties of soft wheat and creation of breeding material with modified activities of the main enzymes involved in amylose biosynthesis. The lines were obtained at the Department of Breeding and Seed Production of Wheat and Triticale, National Center of Grain named after P.P. Lukyanenko, by crossing mutant forms carrying inactive (null) alleles of genes Wx-A1, Wx-B1, and Wx-D1 with bread wheat cultivars. The molecular markers selected for the study allowed identification of valuable breeding material carrying both single null alleles of Wx genes and their combinations in its genome. A combination of two null alleles (Wx-A1b + Wx-D1b) was detected in 30 lines. The presence of three null alleles (Wx-A1b + Wx-B1b + Wx-D1b), which corresponded to fully Wx wheat, was found in one line. We selected 37 lines that combined the presence of the Wx-B1e allele with the Wx-A1b and Wx-D1b null alleles. The Wx-A1b + Wx-B1e combination was identified in 26 lines, and 24 lines carried the combination of alleles Wx-B1e + Wx-D1b. The mutant forms PI619381, PI619384, and PI619386 were identified as carriers of the functional Wx-B1e allele. The Wx-A1b and Wx-B1e alleles could have been transferred to the studied lines from the donors used or from the Starshina and Korotyshka varieties, respectively. The mutant forms used in the crosses are donors of the Wx-B1b and Wx-D1b alleles. The use of molecular markers chosen by us for identification of the allelic state of the Wx-A1, Wx-B1, and Wx-D1 genes can provide grounds for marker-assisted selection for this trait. Selected lines found to possess null alleles of the Wx genes are applicable in breeding programs aimed at the improvement of technological qualities of grain and raise of bread wheat varieties with modified starch properties

A study of bread wheat lines from crosses with the synthetic form Avrodes in regard to their yellow rust resistance

The genome-substituted synthetic form Avrodes (AABBSS) was used for transferring resistance to yellow rust (Puccinia striiformis f. sp. tritici Eriks.) from Aegilops speltoides Tausch, (2n = 14) to bread wheat. The study involved 24 introgressive lines of bread wheat obtained using the Avrodes form. Yellow rust resistant lines P07-L.02, P07-L.1, P07-L.17, P07-L.43, P07-L.19, AS12-88, AS12-06, AS12-07, AS12- 51, Asp81-21, Asp63-21, Asp053-21, Asp04-21, Asp022-19, Asp023-19 and Asp029-20 were selected and can be used as new donors of disease resistance. The use of differential chromosome staining (C-banding) and fluorescence in situ hybridization (FISH) identified the genetic material of Ae. speltoides transmitted in the form of 5S(5D) chromosome substitution and translocations of T5BS.5BL-5SL, T2DL.2DS-2SS, T5D, as well as translocation of T1BL.1RS from Secale cereale L. The work revealed that the lines with single translocations of T1BL.1RS and T5BS.5BL-5SL were susceptible to yellow rust, while the lines in which the T2DL.2DS-2SS translocation and 5S(5D) substitutions were identified, as well as the lines with translocations of T1BL.1RS, T2DL.2DS-2SS and T5D showed resistance to the disease. Presumably, the selected introgression lines, obtained by means of crosses with Avrodes, may carry new genes or loci for yellow rust resistance

The development and study of common wheat introgression lines derived from the synthetic form RS7

Synthetic recombination form RS7 (BBAAUS), in which the first two genomes, A and B, originate from common wheat, and the third recombinant genome consists of Aegilops speltoides (S) and Ae. umbellulata (U) chromosomes, was obtained from crossing synthetic forms Avrodes (BBAASS) and Avrolata (BBAAUU). Resistant to leaf rust, yellow rust and powdery mildew, introgression lines have been obtained from backcrosses with the susceptible varieties of common wheat Krasnodarskaya 99, Fisht and Rostislav. PCR analysis showed the presence of amplification fragments with marker SCS421 specific for the Lr28 gene in the line 4991n17. The cytological study (С-banding and FISH) of 14 lines has revealed chromosomal modifications in 12 of them. In most cases, the lines carry translocations from Ae. speltoides, which were identified in chromosomes 1D, 2D, 3D, 2B, 4B, 5B and 7B. Also, lines with the substituted chromosomes 1S (1B), 4D (4S), 5D (5S) and 7D (7S) were identified. Lines that have genetic material from Ae. speltoides and Ae umbellulata at once were revealed. In the line 3379n14, translocations in the short arm of chromosome 7D from Ae. umbellulata and chromosomes 5BL, 1DL, 2DL from Ae. speltoides were revealed. The line 4626p16 presumably has a translocation on the long arm of chromosome 2D from Ae. umbellulata and the T7SS.7SL-7DL translocation from Ae. speltoides. The T1DS.1DL-1SL and T3DS.3DL-3SL translocations from Ae. speltoides, and T2DS.2DL-2UL and T7DL.7DS-7US from Ae. umbellulata have been obtained for the first time. These lines may carry previously unidentified disease resistance genes and, in particular, leaf rust resistance genes from Ae. speltoides and Ae. umbellulata

USE OF MOLECULAR MARKERS IN WHEAT BREEDING FOR RESISTANCE TO LEAF RUST AT THE LUKYANENKO RESEARCH INSTITUTE OF AGRICULTURE

Wheat accessions were genotyped with molecular markers linked to wheat leaf rust resistance genes Lr9, r10, Lr19,Lr24, Lr26, Lr34, and Lr37. They included 1920 wheat plants and 46 commercial varieties bred at the Lukyanenko Institute. Basically, the analyzed varieties had the inefficient gene Lr10, poorly effi cient Lr26 and Lr34, or their combinations. The highly effi cient genes Lr9 and Lr24 were not detected. The Lr19 gene, effective in the Krasnodar region, was identified in varieties Pallada and Yara. The resistance gene Lr37 was found in variety Morozko. Within a short time, F2 and F3 plants with introgression of genes Lr9, Lr19, Lr24, Lr37 were obtained. Accessions with combinations Lr24 + Lr37, Lr24 + Lr19, Lr24 + Lr9, Lr19 + Lr37, Lr37 + Lr9, Lr19 + Lr9 were identified. Seven plants with the combination of three genes Lr37 + Lr19 + Lr9 and one with Lr37 + Lr24 + Lr9 were selected

IDENTIFICATION OF LEAF RUST RESISTANCE GENES IN SPECIES OF AEGILOPS L., SYNTHETIC FORMS, AND INTROGRESSION LINES OF COMMON WHEAT

DNA samples of wild relatives, synthetic forms and introgression lines of common wheat (Triticum aestivum L.) have been genotyped with diagnostic molecular markers linked to known leaf rust resistance genes Lr9, Lr35 and Lr47. The Lr9 gene is present identified in Aegilops umbellulata, and Lr35 and Lr47, in Ae. speltoides. The synthetic forms Avrolata and Avrodes, with the substitution of the genomes of A е. umbellulata and Aе. speltoides, respectively, for the wheat D-genome, possess Lr9 and Lr35 genes. The genomes of the introgression lines developed using Aе. umbellulata lack Lr9. The Lr35 gene is present in one of the introgression lines derived from Avrodes. Some of the wild relatives and the introgression lines are suggested to have additional leaf rust resistance genes