Genetic control of juvenile resistance to powdery mildew in spring bread wheat cultivars from the VIR collection

Background. Bread wheat (Triticum aestivum L.) is one of the major food crops of humankind. Powdery mildew, caused by Blumeria graminis f. sp. tritici, is the most destructive foliar disease capable of causing great yield losses in epidemic years. Breeding for resistance to powdery mildew is the most economical and effective way to control this disease. By now, 68 loci were identified to contain more than 90 alleles of resistance to powdery mildew in wheat. However, there is a permanent necessity in finding new sources of resistance.The objective of the present study was to characterize the seedling powdery mildew resistance in some spring bread wheat varieties from the VIR collection and determine the inheritance of powdery mildew resistance in these accessions.Materials and methods. The powdery mildew resistant varieties ‘SW Kungsjet’ (k-66036), ‘SW Kronjet’ (k-66097), ‘Boett’ (k-66353), ‘Batalj’ (k-67116), ‘Stilett’ (k-67119) ‘Pasteur’ (k-66093) were crossed with a resistant line ‘Wembley 14.31’ (k-62557) containing the Pm12 gene, and with ‘SW Milljet’ (k-64434); the variety ‘Sibirka Yartsevskaya’ (k-38587) was used as a susceptible parent and control. The hybrid populations F2 were inoculated with the fungus population from local field and evaluated. The powdery mildew population manifested virulence to Pm1a, Pm2, Pm3a-f, Pm4a-b, Pm5a, Pm6, Pm7, Pm8, Pm9, Pm10, Pm11, Pm16, Pm19, Pm28, and avirulence to Pm12. The degree of resistance was assessed on days 8 and 10 after the inoculation using the Mains and Dietz scale (Mains, Dietz, 1930). The castrated flowers in the spikes were pollinated using the twell-method (Merezhko et al., 1973). Chi-squared for goodness of fit test was used to determine deviation of the observed data from the theoretically expected segregation.Results. According phytopathological and genetic tests, juvenile resistance in the varieties ‘SW Kungsjet’, ‘SW Kronjet’, ‘Boett’, ‘Batalj’, ‘Stilett’ and ‘Pasteur’ is controlled by dominant genes, which differ from Pm1a, Pm2, Pm3a-f, Pm4a-b, Pm5a, Pm6, Pm7, Pm8, Pm9, Pm10, Pm11, Pm12, Pm16, Pm19, and Pm28. The varieties ‘SW Milljet’, ‘SW Kronjet’ and ‘Pasteur’ had identical resistance genes. Genetic control of juvenile resistance to powdery mildew in ‘Batalj’, ‘Boett’, ‘Stilett’, ‘SW Milljet’, ‘SW Kungsjet’, ‘Pasteur’ was governed by different genes.Conclusions. The varieties ‘SW Kungsjet’, ‘SW Kronjet’, ‘Boett’ have been maintaining adult and seedling resistance since 2005, and ‘Batalj’, ‘Stilett’ and ‘Pasteur’ since 2017. Seedling resistance of these varieties to local powdery mildew population is controlled by dominant genes. A high degree of resistance was displayed by ‘SW Kungsjet’ and ‘SW Kronjet’ in the Novosibirsk Province, while ‘SW Kungsjet’ was resistant to mildew populations of Tatarstan. The variety ‘Pasteur’ manifested seedling resistance to leaf rust, and ‘SW Kungsjet’ was resistant to loose smut. By summing all the results, it may be suggested that the varieties ‘SW Kungsjet’, ‘SW Kronjet’, ‘Boett’, ‘Batalj’, ‘Stilett’ and ‘Pasteur can serve as good donors of powdery mildew resistance in wheat breeding.

Molecular labeling of Vrn, Ppd genes and vernalization response of the ultra-early lines of spring bread wheat Triticum aestivum L.

Background. The knowledge of genetic control of vernalization response in the ultra-early accessions can facilitate bread wheat breeding for a high adaptive capacity. Materials and methods. The study involved the ultra-early lines Rico (k-65588) and Rimax (k-67257) as the earliest maturing lines in the VIR bread wheat collection, as well as 10 Rifor lines (k-67120, k-67121, k-67250-67256) with a high rate of development before heading. A late ripening accession ‘Forlani Roberto’ (k-42641) and ‘Leningradskaya 6’ variety (k-64900), regionally adapted to Northwestern Russia, were also studied. The alleles of the Vrn and Ppd genes were identified by the PCR analysis using the allele-specific primers published in literature sources. The response to vernalization (30 days at 3°C) and a short 12-hour day were determined using a methodology accepted at VIR. Results. The ultra-early lines respond to a short 12-hour day and 30-day vernalization very poorly. The genotype of ultra-early wheat lines is mainly represented by three genes, Vrn-A1, Vrn-B1a, and Vrn-D1, which ensure insensitivity to vernalization alongside with the expression of Ppd-D1a, which controls the response to photoperiod. The ultra-early lines Rifor 4 and Rifor 5 have a recessive allele vrn-A1a, like the original ‘Forlani Roberto’ accession. The lines Rifor 4 and Rifor 5 are vernalization-insensitive under the long day and have a very weak response under the short day (3.5±0.42 days and 4.0±0.61 days, respectively). However, ‘Forlani Roberto’ with the vrn-A1a gene responds to vernalization in the same way under any photoperiod (12.3±1.58 days and 12.2±0.74 days). Conclusion The ultra-early lines of bread wheat Rifor 4 and Rifor 5 with the vrn-A1a gene can have no response to vernalization or have a low level response. This effect can be a reason for the formation of a complex of modifier genes along with the dominant gene Vrn-D1, which forms during the hybridization of F7-8 Rico × Forlani Roberto. The ultra-early lines of bread wheat Rico, Rimax and Rifor (k-67120, k-67121, k-67250-67256) can serve as effective sources of genes for earliness in common wheat breeding.

A prebreeding study of introgression spring bread wheat lines carrying combinations of stem rust resistance genes, Sr22+Sr25 and Sr35+Sr25

The Sr22, Sr35, and Sr25 genes attract the attention of bread wheat breeders with their effectiveness against Puccinia graminis f. sp. tritici race Ug99 and its biotypes. The effectiveness and impact of Sr22+Sr25 and Sr35+Sr25 gene combinations on agronomic traits have not yet been studied. In the present article, these traits were studied using the spring bread wheat lines L503/W3534//L503, L503/Sr35//L503/3/L503 carrying the Sr22+Sr25 and Sr35+Sr25 genes during 2016–2020. These lines were assessed for resistance to P. graminis f. sp. tritici under natural epiphytotics and to the Saratov, Lysogorsk and Omsk populations of the pathogen and to the PgtZ1 (TKSTF) and PgtF18.6 fungus isolates in laboratory conditions (TKSTF + Sr33). The presence of the studied Sr-genes was confirmed by using molecular markers. Prebreeding studies were conducted during 2018–2020 vegetation periods. Under the natural epiphytotics of the pathogen and in the laboratory conditions, the Sr22+Sr25 combination was highly effective, while Sr35+Sr25 was ineffective. For grain yield, the lines with the Sr22+Sr25 and Sr35+Sr25 genes were superior to the recipient cultivar L503 in one year (Sr22+Sr25 in 2019; Sr35+Sr25 in 2018), with a decrease in 2020, but in general there were no differences. For the period 2018–2020, both combinations showed a decrease in 1000 grains weight and an increase in the germination-earing period. The line with Sr22+Sr25 genes showed insignificant effects on gluten and dough tenacity, but the ratio of dough tenacity to extensibility was higher, and flour strength, porosity and bread volume were lower; in the line with Sr35+Sr25 genes, the gluten content was lower, but the strength, tenacity of the dough and the ratio of dough tenacity to extensibility were higher, flour strength and the porosity of the bread were at the recipient level, but the volume of bread was lower.

Biochar Reduces the Adverse Effect of Saline Water on Soil Properties and Wheat Production Profitability

The goal of this study is to assess the use of saline groundwater in combination with soil amendments to increase the efficiency of wheat production in new agricultural soil in Egypt. The experiment was conducted during the two consecutive growing seasons, 2019/2020 and 2020/2021, at the Shandaweel Agricultural Research Station, Sohag, Egypt. In this study, plants of Shandaweel 1 spring bread wheat cultivar were grown under the combinations of the two water treatments, i.e., freshwater (307.2 ppm) and saline water (3000 ppm (NaCl + MgCl2)) representing groundwater in Egypt delivered by drip irrigation and the two biochar rates, i.e., zero and 4.8 ton/ha as a soil amendment. The cob corn biochar (CCB) was synthesized by using the slow pyrolysis process (one hour at 350 °C). The results revealed that saline water reduced the grain yield ratio by 8.5%, 11.0%, and 9.7% compared to non-saline water during seasons 2019/2020 and 2020/2021 and over seasons, respectively. Concerning, combined over seasons, the biochar addition enhanced the grain yield by 5.6% and 13.8% compared to non-biochar addition under fresh and saline irrigation water conditions, respectively. Thus, the results indicated and led to a preliminary recommendation that saline groundwater is a viable source of irrigation water and that biochar seemed to alleviate salinity stress on wheat production and in reclaimed soils of Egypt.

Изучение полиморфизма эстеразных изоферментов в семенах картирующей популяции яровой мягкой пшеницы

Using electrophoresis, in 114 recombinant hybrid lines of the mapping population of spring bread wheat and in 2 parental forms, 7 esterase isoenzymes were found: A1-A7 (Mr 93-138 kDa). According to their esterase composition, all samples were subdivided into 17 zymotypes. Isoforms A4 and A6 are pre-sent in all zymotypes, i.e. are monomorphic. The other 5 isozymes provide a high level of polymorphism in the population. The majority of genotypes belong to the zymotype Gr. 1 (27%), which includes 6 isoforms. Among them there are isoforms A1 and A7, characteristic only for each of the parent forms, which indicates the codominant inheritance of these isoenzymes.

Genotypic and ecological variability of zinc content in the grain of spring bread wheat varieties in the international nursery KASIB

Spring bread wheat is the staple crop in Western Siberia and Kazakhstan, a significant portion of which goes for export. Wheat breeding with a high level of zinc in wheat grain is the most cost-effective and environmentally friendly way to address zinc deficiency in the diet. The purpose of this work was to evaluate the contribution of the factors ‘location’ and ‘genotype’ in the variability of zinc content in wheat grain, and to identify the best varieties as sources of this trait for breeding. The research on screening zinc content in the wheat grain of 49 spring bread wheat varieties from the KazakhstanSiberia Spring Wheat Trial (KASIB) nursery was carried out at 4 sites in Russia (Chelyabinsk, Omsk, Tyumen, Novosibirsk) and 2 sites in Kazakhstan (Karabalyk and Shortandy) in 2017–2018. The content of zinc in wheat grain was evaluated at the Ionomic Facility of University of Nottingham in the framework of the EU project European Plant Phenotyping Network-2020. The analysis of variance showed that the main contribution into the general phenotypic variation of the studied trait, 38.7 %, was made by the factor ‘location’ due to different contents of zinc and moisture in the soil of trial sites; the effect of the factor ‘year’ was 13.5 %, and the effect of the factor ‘genotype’ was 8.0 %. The most favorable environmental conditions for accumulation of zinc in wheat grain were observed in the Omsk region. In Omsk, the average zinc content in all studied varieties was 50.4 mg/kg, with 63.7 mg/kg in the best variety ‘OmGAU 100’. These values are higher than the target values of the international program Harvest Plus. ‘Novosibirskaya 16’ (49.4 mg/kg), ‘Silach’ (48.4 mg/kg), ‘Line 4-10-16’ (47.2 mg/kg), ‘Element 22’ (46.3 mg/kg) and ‘Lutescens 248/01’ (46.0 mg/kg) were identified as being the best varieties. Significant possibilities for the production of wheat grain with high zinc content, which is in demand for the production of bread and pastry products with functional properties, were identified in the Western Siberian region.

Spring wheat productivity and grain quality in the crop rotation of the foreststeppe of Western Siberia

Spring bread wheat is cultivated in the Omsk region, mainly in grain-fallow crop rotations, repeated and perma[1]nent crops, less in crop-changing rotations and occupies up to 73% of the grain share of Western Siberia. Soybean crops are growing in the region, but at the same time, there have not been sufficiently studied the peculiarities of the cultivation technology of spring wheat sown after this forecrop. The purpose of the current study was to establish the efficiency of agricultural cultivation technologies of spring wheat in the crop rotation sown after soybean in the southern forest-steppe of Western Siberia. The study was carried out in a stationary crop rotation with alternating crops (soy[1]beans – spring wheat – oil flax – barley) in the laboratory for resource-saving agricultural technologies of the Omsk Research Center on meadow-blackearth soil in 2011–2019. There has been established that the soil cultivation system and the means of intensification influenced the elements of fertility and the phytosanitary state of the agrophytocenosis of spring wheat sown after soybean. With subsurface plowing, in comparison with moldboard plowing, there was an increase in biomass and number of weeds on 21 and 43%, respectively. The use of chemicals resulted in a significant increase in spring wheat biomass (on 1.8 times) and a decrease in number of weeds (on 3.3 times), which had a noticeable effect on the productivity. Productivity of wheat sown after soybeans decreased with a decrease in tillage intensity from moldboard plowing to subsurface plowing on 16%. The intensive cultivation technology of spring wheat increased its productivity up to 3.32 t / ha, the protein and gluten content in grain on 16–18%. As for chemicals, the maximum grain number increase on 28.2% was provided by the use of fungicides compared to the control (1.46 t/ha).

Effect of Flowering Time-Related Genes on Biomass, Harvest Index, and Grain Yield in CIMMYT Elite Spring Bread Wheat

Grain yield (YLD) is a function of the total biomass (BM) and of partitioning the biomass by grains, i.e., the harvest index (HI). The most critical developmental stage for their determination is the flowering time, which mainly depends on the vernalization requirement (Vrn) and photoperiod sensitivity genes (Ppd) loci. Allelic variants at the Vrn, Ppd, and earliness per se (Eps) genes of elite spring wheat genotypes included in High Biomass Association Panel (HiBAP) I and II were used to estimate their effects on the phenological stages BM, HI, and YLD. Each panel was grown for two consecutive years in Northwest Mexico. Spring alleles at Vrn-1 had the largest effect on shortening the time to anthesis, and the Ppd-insensitive allele Ppd-D1a had the most significant positive effect on YLD in both panels. In addition, alleles at TaTOE-B1 and TaFT3-B1 promoted between 3.8% and 7.6% higher YLD and 4.2% and 10.2% higher HI in HiBAP I and II, respectively. When the possible effects of the TaTOE-B1 and TaFT3-B1 alleles on the sink and source traits were explored, the favorable allele at TaTOE-B1 showed positive effects on several sink traits mainly related to grain number. The favorable alleles at TaFT3-B1 followed a different pattern, with positive effects on the traits related to grain weight. The results of this study expanded the wheat breeders’ toolbox in the quest to breed better-adapted and higher-yielding wheat cultivars.

Comparison of productivity elements of recombinants of spring bread wheat with translocation from Thinopyrum elongatum carrying rust resistance genes

There have been presented the results of a comparative estimation of recombinants developed on the basis of two commercial varieties (‘Sibirskaya 17’ and ‘Novosibirskaya 31’) hybridized with ‘Thatcher Lr19’ and ‘Thatcher Lr24’. Recombinants were evaluated in the field conditions in 2016, 2017 and 2020. The purpose of the current study was to identify the effect of translocations from Thinopyrum elongatum on the manifestation of productivity elements in recombinants of spring bread wheat developed on the basis of two commercial varieties. The analysis of the genetic composition of the Puccinia triticina populations in Western and Eastern Siberia did not identify genes which were virulent to resistance genes Lr19, Lr24, Lr28, Lr41, Lr47, Lr45 LrSp, Lr6Agi 1 and Lr6Agi 2. The recombinants developed on the basis of the variety ‘Sibirskaya 17’ (the variety productivity was 398.3 g/m2 , grain weight per head was 1.35 g, 1000-grain weight was 37.8 g) were characterized by the severity of the main agronomically valuable traits at the level of the recipient variety, or significantly lower (productivity was 271.5–327.8 g/m2 , grain weight per head was 1.03–1.16 g, 1000-grain weight was 32.5–36.4 g). The recombinants carrying translocations (the length of the period ‘sprouts-heading’ was 44.4 and 44.5 days, grain weight per head was 1.20 and 1.24 g) developed on the basis of the variety ‘Novosibirskaya 31’ (with 42.4 days, 1.02 g) have demonstrated a significant increase in the length of the period ‘sprouts-heading’ and grain weight per head in comparison with the recombinants without translocations (41.6 and 43.6 days, 0.99 and 1.10 g). On average over 3 years, 12 recombinants hybridized from the combination ‘Novosibirskaya 31 x Thatcher Lr19’ produced higher yields (355.6–427.5 g/m2) than those of the recipient variety (301.5 g/m2), both with (6 pcs.), and without (6 pcs.) a translocation.