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Most modern breeding programs aim to develop wheat (T. aestivum L.) varieties with a high grain protein content (GPC) due to its greater milling and cooking quality, and improved grain price. Here, we used a genome-wide association study (GWAS) to map single nucleotide polymorphisms (SNPs) associated with GPC in 93 spring bread wheat varieties developed by eight Russian Breeding Centers. The varieties were evaluated for GPC, grain weight per spike (GWS), and thousand-kernel weight (TKW) at six environments, and genotyped with 9351 polymorphic SNPs and two SNPs associated with the NAM-A1 gene. GPC varied from 9.8 to 20.0%, depending on the genotype and environment. Nearly 52% of the genotypes had a GPC > 14.5%, which is the threshold value for entry into high-class wheat varieties. Broad-sense heritability for GPC was moderate (0.42), which is due to the significant effect of environment and genotype × environment interactions. GWAS performed on mean GPC evaluated across six environments identified eleven significant marker-trait associations, of which nine were physically mapped on chromosome 6A. Screening of wheat varieties for allelic variants of the NAM-A1 gene indicated that 60% of the varieties contained the NAM-A1c allele, followed by 33% for NAM-A1d, and 5% for NAM-A1a alleles. Varieties with the NAM-A1d allele showed significantly (p < 0.01) smaller GPC than those with NAM-A1c and NAM-A1a. However, no significant differences between NAM-A1 alleles were observed for both GWS and TKW.

Cultivation of winter wheat varieties in the West Siberian region of Russia has competitive advantages compared to spring varieties: utilization of spring-summer moisture, early maturation and harvest and a high yield potential. The poor resistance of winter varieties to foliar diseases results in significant yield losses and facilitates the spread of pathogens to the spring wheat cultivars. The present study was conducted to evaluate the effectiveness of molecular markers specific for VRN-1 and Lr loci in selecting winter wheat genotypes resistant to leaf rust. The winter wheat cultivars Biyskaya ozymaya and Filatovka were crossed with spring wheat introgression lines 21-4 and 5366-180 and the spring wheat cultivar Tulaikovskaya 10 carrying LrTt2, LrAsp5 and Lr6Ai#2 loci from Triticum timopheevii, Aegilops speltoides and Thynopyrum intermedium, respectively. To identify winter wheat plants homozygous for target loci, F 2 populations were screened with functional markers to VRN-1 genes and with markers specific for alien genetic material. Based on the genotyping analysis of 371 F 2 plants a total of 44 homozygous genotypes with winter habit was identified. There were eight genotypes containing Lr loci among them. Evaluation of F 2-derived F 3-4 families for both seedling and adult resistance showed that only one F 3-4 family had moderate susceptible reaction type to the field population of leaf rust. Others ranged from nearly immune to resistant with severity of 5%. The data also indicated the utility of the VRN-1 allele-specific markers for detection of genotypes with winter habit without vernalization at early stages of plant breeding.

A b s t r a c tSpring wheat is the main cereal crop in the West Siberian region of Russia and occupies more than 40 % of the acreage. The widening of the genetic diversity of this culture and the creation of new varieties with high productivity and resistance to environmental factors have always been a key problem of breeding. Winter wheat varieties which are characterized by a wide diversity of useful characters such as tolerance to abiotic stressors, productive tillers and yield can be used as a promising source of agronomically important traits. Despite the fact that the methodological approach to the introgression of the gene pool of winter wheat into the genome of spring wheat has been in use for a long time to increase the yield of spring varieties, at the moment there is little available information concerning the manifestation of valuable traits in offspring obtained from the winter and spring wheat hybridization. However, such results are important for assessing the combining ability of winter and spring wheat varieties and for the selection of potential parents by a complex of characters. For the identification of the winter and spring genotypes in the offspring resulting from the hybridization of winter and spring parents with the help of convenient breeding methods, a large sample size populations and a long period of cultivation of plant material are required. The application of MAS technologies and markers linked to the target loci can significantly decrease the time of development of new breeding lines. In creation of breeding lines resistant to leaf rust, the winter wheat varieties Filatovka and Biyskaya ozymaya, adapted for cultivation in the West Siberian region, were involved in a scheme of hybridization. Spring wheat introgression line 5366-180 (Triticum aestivum/T. timopheevii) и spring wheat cultivar Tulaikovskaya 10, containing genetic material of Thinopyrum intermedium were the donors of effective leaf rust resistance genes LrTt2 and Lr6Ai#2. The aim of this work was to evaluate the diversity of spring wheat forms obtained from these crosses on economically important traits and analysis of the genotype influence on their manifestation. The plants differing in winter and spring habits were selected in F 2 progeny by means of allele-specific markers to the VRN-1 genes. To identify genotypes containing leaf rust resistance genes, a microsatellite marker Xbarc232 and primers MF2/MR1r2 and MF2/MR4 specific for T. timopheevii and Th. intermedium translocations, respectively, were used. As a result of hybridization of winter varieties with spring donors, 122 F 2 plants were obtained, of which 30 homozygous spring plants with different allelic composition of VRN-1 genes were selected. Of these, 12 plants according to molecular data with Lr-specific primers contained alien translocations. For the comparative analysis of agronomic traits, six F 2 plants were used which possessed the same allelic composition of VRN-1 genes as in the initial spring donors but differed in the presence or absence of Lr...

Мягкая яровая пшеница-одна из широко возделываемых зерновых культур в Российской Федерации. Селекция яровой пшеницы направлена на создание сортов, характеризующихся высокой урожайностью и качеством зерна. Основное внимание при создании новых сортов обращают на устойчивость к климатическим факторам, которые отрицательно влияют на стабильность урожайности. Что касается скрещиваний озимых и яровых сортов пшеницы, то в настоящее время нет достаточной информации о проявлении и наследовании признаков продуктивности в более старших поколениях и в различных агроэкологических условиях. В представляемой работе мы изучили изменчивость элементов структуры урожая у 55 селекционных линий мягкой пшеницы (Triticum aestivum L.) поколений F6-7, полученных от скрещивания озимых сортов мягкой пшеницы с яровыми донорами генов устойчивости к бурой ржавчине, с целью выделения генотипов, перспективных в качестве источников ценных агрономических признаков. Полевые исследования проводили в 2018 году в трех регионах-в Новосибирской и Омской областях и в Республике Татарстан. Оценивали следующие элементы структуры урожая: число продуктивных стеблей, число зерен с колоса, масса зерна с колоса, масса 1000 зерен и масса зерна с растения. Экологическую пластичность линий характеризовали с помощью показателей интенсивности и устойчивости индекса стабильности. Дисперсионный анализ, выполненный по результатам экологических испытаний, свидетельствует о достоверном (p < 0,001) влиянии генотипа, внешней среды и их взаимодействия на фенотипическое проявление всех изученных признаков. Наиболее высокий вклад генотипа показан для признаков число зерен с колоса (42,8 %) и масса 1000 зерен (57,0 %). Высокий вклад условий внешней среды установлен для продуктивной кустистости (41,8 %) и массы зерна с колоса (40,3 %). Для всех признаков существенное влияние оказывало взаимодействие генотип ½ среда, вклад которого варьировал от 25,9 % (масса 1000 зерен) до 41,0 % (масса зерна с колоса), что свидетельствует о значительной реакции генотипов на изменяющиеся условия. При полевых испытаниях наблюдалась высокая изменчивость всех признаков во всех трех климатических зонах, однако степень вариаций была различной. Усредненные показатели изученных признаков были ниже в полевых условиях Омской зоны по сравнению с Новосибирской областью и Татарстаном. Более высокие флуктуации отмечены для числа зерен с колоса (от 13,0 до 69,0), массы зерна с колоса (от 0,35 г до 2,65 г) и массы зерна с растения (от 0,15 г до 6,95 г) в условиях Татарстана по сравнению с другими регионами. Расчет индексов стабильности, устойчивости индексов стабильности и индексов интенсивности установил, что 16 генотипов из 55 входят в группу сортов интенсивного типа, 35-полуинтенсивного и 4-экстенсивного. Анализ методом главных координат разделил образцы на четыре основных кластера по типу стабильности и интенсивности. Молекулярный анализ селекционных линий на наличие генов устойчивости к бурой ржавчине Lr6Ai#2, LrAsp5 и LrTt2, интродуцированных соответственно от Thinopyrum intermedium (Host) Barkworth & ...

The existing spring forms of wheat-rye amphiploids are characterized by late maturity due to the long duration of the interphase period “germination–heading”. The manifestation of this trait is influenced by Vrn-1 genes. Their dominant alleles also determine the spring type of development. The results of studying the interphase period “germination–heading” of spring octaploid and hexaploid forms of triticale created for use in research and breeding programs under the conditions of forest-steppe of Western Siberia are given in this article. The interphase period of the primary forms 8xVrnA1, 8xVrnB1 and 8xVrnD1 obtained by artificial doubling of the chromosome number of the wheat-rye hybrids made by pollination of three lines of the soft wheat ‘Triple Dirk’ – donors of different dominant Vrn-1 genes – by a winter rye variety ‘Korotkostebel’naya 69’ was determined under the field conditions in the nursery of octaploid (8x) triticale. In the nursery of hexaploid triticale, this trait was studied in the populations of hybrids obtained by hybridization of these three primary forms of octaploid triticale with the hexaploid winter triticale variety ‘Sears 57’. In the offspring of crossing 8хVrnD1× ‘Sears 57’, spring genotypes of 6x triticale bearing Vrn-D1 were selected. This fact was determined by PСR. It means that the genetic material from the chromosome of the fifth homeologous group of the D genome of the bread wheat is included in the plant genotypes. This genome is absent in the winter 6x triticale ‘Sears 57’. The grain content of spikes of the created hexaploid forms of triticale is superiour to that of the maternal octaploid triticale forms. It was shown that plants of the hybrid populations 8xVrnA1× ‘Sears 57’ and 8xVrnD1× ‘Sears 57’ carrying the dominant alleles Vrn-A1a and Vrn-D1a, respectively, have a shorter duration of the “germination–heading” interphase period than the initial parental forms of primary 8x triticale. The short interphase period of “germination–heading” of the 6x triticale is a valuable breading trait for the creation of early maturing and productive genotypes of triticale.

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