Introgression of common wheat lines with genetic material of Agropyron glaucum

Grey wheatgrass Agropyron glaucum (Desf. ex DC) Roem. & Schult is a valuable source of genes for resistance to diseases, frost resistance, and salt tolerance. An unstable 76-chromosomal amphidiploid combining genomes A and B of common wheat variety Avrora, six chromosomes of genome D of the same variety, and a full set of Ag. glaucum (2n = 42) chromosomes was used as an intermediate to transfer the genetic material from the wild donor to the said wheat variety. A large set of wheat introgression lines differing in a variety of morphobiological characters was developed. For effective employment of the developed lines in breeding, cytological and molecular-genetical analyses of the lines were conducted, and their pest resistance and grain technological properties were evaluated. We report the investigation of 25 common wheat introgression lines with genetic material from Ag. glaucum, not studied hitherto. All lines but D43 formed 21 bivalents in МI meiosis. In lines D3, D21, and D23, the genetic material of Ag. glaucum was present as a translocation segment. Lines D7, D43, and D49 carried substituted chromosomes and, presumably, translocations. One pair of wheat chromosomes was substituted in 18 lines. For the identification of translocations and substituted chromosomes, microsatellite analysis was done with markers specific to D genome chromosomes. The introgression touched all D genome chromosomes except 3D and 4D. The lines under the study differed in protein and gluten contents, gluten quality, and bread-making quality. Study of gliadin spectra revealed changes in the gliadin formula in 7 of 12 lines with reference to the recipient Avrora variety. Thus, the results obtained point to genetic diversity of investigated introgression lines and their value for common wheat breeding

STUDY OF INTROGRESSIVE LINES OF COMMON WHEAT WITH Aegilops tauschii GENETIC MATERIAL FOR RESISTANCE TO LEAF RUST

The synthetic forms of Triticum miguschovae (GGAADD), Triticum palmovae (AbAbDD), T. durum (M. it.)/Ae. Tauschii (BBAADD) and the introgressive lines of common wheat created on their basis were evaluated for resistance to leaf rust. All synthetic forms have a high resis­tance to leaf rust. Twenty-two lines of common wheatresistant to leaf rust with genetic material from T. miguschovae, 10 lines with genetic material from T. du­rum (M. it.)/Ae. tauschii and 4 lines obtained on the basis of T. palmovae were identified. A screening with the use of molecular markers for the presence of leaf rust resistance genes Lr21, Lr26, Lr32, Lr39 was done. The GDM35 marker linked to the Lr39 gene was identified in the synthetic forms. Molecular markers Lr21F/R and BARC135 linked to the genes Lr21 and Lr32, respectively, were not identified. Resistance to leaf rust in lines 729, 1555, 2203, 2289, 2295, 2296, 4155, 4171, obtained on the basis of T. miguschovae, lines 3261, 3265, obtained on the basis of T. palmovae, and in line 4141 with the genetic material from T. durum (M. it.)/Ae. Tauschii is controlled by the presence of the Lr39 gene. The SCM9 marker indicating the presence of translocation of 1BL.1RS with the Lr26 gene was detected in 15 lines obtained on the basis of T. miguschovae, in 2 lines with genetic material from T. durum (M. it.)/Ae. tauschii, and in 1 line created on the basis of T. palmovae. Lines 729, 1555, 2203, 2289, 2295, 2296, 4155, 4171 obtained with the participation of T. miguschovae and line 3261 with the participation of T. palmovae carry a combination of genes (Lr39+Lr26)

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

Use of a synthetic form Avrodes for transfer of leaf rust resistance from Aegilops speltoides to common wheat

Diploid wild relative of wheat – Aegilops speltoides – is a valuable source of genes for resistance to diseases. The synthetic form Avrodes (BBAASS) was used as a bridge to transfer leaf rust resistance genes from Ae. speltoides to common wheat. Introgression lines obtained from crosses of Avrodes and susceptible common wheat cultivars were evaluated in a field leaf rust nursery. Resistance levels varied from high to moderate. Testing of lines with the use of molecular markers has shown that some lines have the Lr28 and Lr35 genes inherited from synthetic form Avrodes. The majority of resistance lines have not been found to carry these genes. The Lr47 and Lr51 genes were not identified in the Avrodes and introgression lines. The analysis of chromosome pairing in F1 hybrids showed that the transfer of a genetic material from Avrodes to common wheat basically occurs through translocations. Lines with translocations on chromosomes 2D and 5D were identified by C-banding and FISH. The translocations differed in chromosomal location from known leaf resistance genes transferred to common wheat from Ae. speltoides. Hence it was assumed that new genes were introduced into the common wheat genome from Ae. speltoides. Introgression lines have been studied for productivity and technological qualities of grain. Lines AA60n9 and D37n10 combine high resistance to leaf rust with good characteristics of productivity and technological qualities of grain. The received results demonstrate a genetic diversity and a value of the investigated introgression lines for breeding of common wheat

Using the synthetic form RS5 to obtain new introgressive lines of common wheat

The use of the gene pool of wild relatives, which have a significant reserve of genetic diversity, is of immediate interest for breeding common wheat. The creation and use of synthetic forms as “bridges” is an effective method of transferring valuable genetic material from wild relatives to cultivated wheat. For this purpose, genome addition, genome substitution and recombinant “secondary” synthetic forms have been created in the P.P. Lukyanenko National Center of Grain. The synthetic recombination form RS5 (BBAASDt ), in which the third genome consists of chromosomes of Aegilops speltoides (S) and Aegilops tauschii (Dt ), was obtained from crossing the synthetic forms Avrodes (BBAASS) and M.it./Ae. tauschii (BBAADt Dt ), in which the D genome from Ae. tauschii was added to the BBAA genomes of the durum wheat cultivar Mutico italicum. Introgression lines resistant to leaf rust, yellow rust and powdery mildew have been obtained from backcrosses with the susceptible common wheat cultivars Krasnodarskaya 99, Rostislav and Zhirovka. Twelve resistant lines that additionally have high technological characteristics of grain and flour have been selected. The cytological study (С-banding) has revealed chromosomal modifications in 6 of 8 lines under study. The rearrangements mainly affected the chromosomes of the D genome, 1D, 3D, 4D, 6D and 7D. It was found that in most cases the genetic material from the synthetic form RS5 in the studied lines was represented by substituted chromosomes from Ae. tauschii. In line 5791p17, the substitution of chromosomes 6D from Ae. tauschii and 7D from Ae. speltoides was revealed. Substitutions 4D(4Dt ), 6D(6Dt ) from Ae. tauschii and 7D(7S) from Ae. speltoides were obtained for the first time. Molecular analysis of 12 lines did not reveal effective leaf rust resistance genes, presumably present in synthetic forms of M.it./Ae. tauschii and Avrodes. It is assumed that the lines may carry previously unidentified genes for fungal disease resistance, in particular for resistance to leaf rust, from Ae. tauschii and Ae. speltoides

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

Feasibility, acceptability, and effectiveness of non-pharmaceutical interventions against infectious diseases among crisis-affected populations: a scoping review

BACKGROUND: Colonization of large part of Europe by the Asian tiger mosquito Aedes albopictus is causing autochthonous transmission of chikungunya and dengue exotic arboviruses. While pyrethroids are recommended only to reduce/limit transmission, they are widely implemented to reduce biting nuisance and to control agricultural pests, increasing the risk of insurgence of resistance mechanisms. Worryingly, pyrethroid resistance (with mortality < 70%) was recently reported in Ae. albopictus populations from Italy and Spain and associated with the V1016G point mutation in the voltage-sensitive sodium channel gene conferring knockdown resistance (kdr). Genotyping pyrethroid resistance-associated kdr mutations in field mosquito samples represents a powerful approach to detect early signs of resistance without the need for carrying out phenotypic bioassays which require availability of live mosquitoes, dedicated facilities and appropriate expertise. METHODS: Here we report results on the PCR-genotyping of the V1016G mutation in 2530 Ae. albopictus specimens from 69 sampling sites in 19 European countries. RESULTS: The mutation was identified in 12 sites from nine countries (with allele frequencies ranging from 1 to 8%), mostly distributed in two geographical clusters. The western cluster includes Mediterranean coastal sites from Italy, France and Malta as well as single sites from both Spain and Switzerland. The eastern cluster includes sites on both sides of the Black Sea in Bulgaria, Turkey and Georgia as well as one site from Romania. These results are consistent with genomic data showing high connectivity and close genetic relationship among West European populations and a major barrier to gene flow between West European and Balkan populations. CONCLUSIONS: The results of this first effort to map kdr mutations in Ae. albopictus on a continental scale show a widespread presence of the V1016G allele in Europe, although at lower frequencies than those previously reported from Italy. This represents a wake-up call for mosquito surveillance programs in Europe to include PCR-genotyping of pyrethroid resistance alleles, as well as phenotypic resistance assessments, in their routine activities

Geographic distribution of the V1016G knockdown resistance mutation in aedes albopictus. A warning bell for Europe

Background: Colonization of large part of Europe by the Asian tiger mosquito Aedes albopictus is causing autochthonous transmission of chikungunya and dengue exotic arboviruses. While pyrethroids are recommended only to reduce/limit transmission, they are widely implemented to reduce biting nuisance and to control agricultural pests, increasing the risk of insurgence of resistance mechanisms. Worryingly, pyrethroid resistance (with mortality &lt; 70%) was recently reported in Ae. albopictus populations from Italy and Spain and associated with the V1016G point mutation in the voltage-sensitive sodium channel gene conferring knockdown resistance (kdr). Genotyping pyrethroid resistance-associated kdr mutations in field mosquito samples represents a powerful approach to detect early signs of resistance without the need for carrying out phenotypic bioassays which require availability of live mosquitoes, dedicated facilities and appropriate expertise.Methods: Here we report results on the PCR-genotyping of the V1016G mutation in 2530 Ae. albopictus specimens from 69 sampling sites in 19 European countries.Results: The mutation was identified in 12 sites from nine countries (with allele frequencies ranging from 1 to 8%), mostly distributed in two geographical clusters. The western cluster includes Mediterranean coastal sites from Italy, France and Malta as well as single sites from both Spain and Switzerland. The eastern cluster includes sites on both sides of the Black Sea in Bulgaria, Turkey and Georgia as well as one site from Romania. These results are consistent with genomic data showing high connectivity and close genetic relationship among West European populations and a major barrier to gene flow between West European and Balkan populations.Conclusions: The results of this first effort to map kdr mutations in Ae. albopictus on a continental scale show a widespread presence of the V1016G allele in Europe, although at lower frequencies than those previously reported from Italy. This represents a wake-up call for mosquito surveillance programs in Europe to include PCR-genotyping of pyrethroid resistance alleles, as well as phenotypic resistance assessments, in their routine activities