The relationship between the genetic status of the Vrn-1 locus and the size of the root system in bread wheat (Triticum aestivum L.)

One of the main ways to fine-tune the adaptive potential of wheat cultivars is to regulate the timing of flowering using the genes of the Vrn-1 locus, which determines the type and rate of development. Recently, with the use of introgression and isogenic lines of bread wheat, it was shown that this locus is involved in the genetic control of root length and weight both under irrigation and drought conditions. It turned out that the VrnA1 gene is associated with a significant decrease in the size of the root system in a winter genotype. The Vrn-A1 gene had the strongest effect on the reduction of the root system in comparison with the homoeoallelic genes Vrn-B1 and Vrn-D1. The aim of this work was to determine whether the allelic composition of the genes at the Vrn-1 locus affects the root size in seven spring cultivars and in two lines of bread wheat differing in flowering time under conditions of normal watering and drought. The research was carried out in a hydroponic greenhouse; drought was created at the tillering stage. In this work, we have shown that early flowering wheat cultivars with the dominant Vrn-A1а allele have more lightweight and shorter roots under normal watering conditions compared to the late flowering carriers of the dominant homoeoalleles Vrn-B1 and Vrn-D1. In drought conditions, the root length decreased insignificantly, but the weight of the roots significantly decreased in all genotypes, with the exception of Diamant 2. It has been hypothesized that the level of the transcription factor VRN-1 at the onset of drought may affect the size of the root system. The large variability in root weight may indicate the participation, in addition to the Vrn-1 locus, of other gene networks in the formation of this trait. Breeders working to develop early maturing varieties should consider the possibility of reducing the root size, especially in arid conditions. A significant increase in the root size of line 821 with introgressions into chromosomes 2A, 2B, and 5A from T. timopheevii indicates the possibility of using congeners as a source of increasing the trait in wheat

Technological properties of grain and flour in bread wheat (<i>Triticum aestivum</i> L.) genotypes carrying two loci that determine the endosperm structure

Background. The end-use of the bread wheat grain depends on the endosperm properties determined by the alleles of the Pina and Pinb genes at the Ha locus on chromosome 5D. The mealy (soft) endosperm is generated by the biosynthesis of puroindolines – complete proteins encoded by these genes. When milled, such grain breaks down into small starch granules covered with proteins. Mutations that disrupt the synthesis or structure of puroindolines determine the hardness and vitreousness of the grain. Earlier, we discovered a new locus for grain softness, Ha-Sp, introgressed from the diploid species Aegilops speltoides Tausch, which also determines the formation of the soft endosperm structure. By combining two active loci in one genotype, we produced a supersoft grain line (SSL). The aim of the present work was to verify the interaction of the two loci Ha and Ha-Sp in other wheat genotypes and evaluate the technological properties of grain and flour in comparison with the existing SSL line.Materials and methods. The F3–F8 hybrids from crosses of the soft-grain spring cultivars ‘Golubka’ and ‘Lutescens 62’, carriers of the Ha locus, with the introgressive line 84/98w, carrier of the Ha-Sp locus, were used in the work. Grain from three field seasons was studied according to milling parameters and physical properties of flour and dough.Results. At the early stages of selection (F3:4), the families with milling parameters typical of bread wheat were identified, as well as supersoft-grain families with a small flour particle size (9–10 μm) and low endosperm vitreousness (29–49%). Targeted selection made it possible to obtain lines similar to the SSL line in terms of milling performance and flour strength.Conclusion. For the first time, a set of supersoft-grain lines with special properties of grain and flour was obtained on the genetic basis of three spring cultivars. They may be in demand for a wide range of end-uses, including both food and nonfood production purposes

Chromosomal location and mapping of quantitative trait locus determining technological parameters of grain and flour in strong-flour bread wheat cultivar saratovskaya 29

Bread wheat is the primary bread crop in the majority of countries in the world. The most important product that is manufactured from its grain and flour is yeast bread. In order to obtain an excellent bread, grain with high physical properties is needed for flour and dough. The Russian spring wheat cultivar Saratovskaya 29 is characterized by its exclusively high physical properties of flour and dough. The purpose of this work was to identify the chromosomes carrying the main loci for these traits in Saratovskaya 29 and to map them using recombinant substitution lines genotyped with molecular markers. A set of inter-varietal substitution lines Saratovskaya 29 (Yanetzkis Probat) was used to identify the “critical” chromosomes. The donor of individual chromosomes is a spring cultivar with average dough strength and tenacity. Substitution of 1D and 4D*7A chromosomes in the genetic background of Saratovskaya 29 resulted in a significant decrease in the physical properties of the dough. Such a deterioration in the case of 1D chromosome might be related to the variability of gluten protein composition. With the help of recombinant substitution double haploid lines obtained from a Saratovskaya 29 (Yanetzkis Probat 4D*7A) substitution line the region on the 4D chromosome was revealed in the strong-flour cultivar Saratovskaya 29, with the microsatellite locus Xgwm0165 to be associated with the unique physical properties of flour and dough. The detected locus is not related to the composition gluten proteins. These locus may be recommended to breeders for the selection of strong-flour cultivars. Additionally, a QTL associated with vitreousness of grain was mapped in the short arm of chromosome 7A

Phenotypic diversity of bread wheat lines with introgressions from the diploid cereal Aegilops speltoides for technological properties of grain and f lour

The creation of varieties adapted to changing environmental conditions, resistant to various pathogens, and satisfying various grain purposes is impossible without using the genetic diversity of wheat. One of the ways to expand the genetic diversity of wheat is to introduce new variants of genes from the genetic pool of congeners and wild relatives into the genotypes of existing varieties. In this study, we used 10 lines from the Arsenal collection created on the genetic basis of the spring variety ‘Rodina’ and the diploid species Aegilops speltoides in the Federal Research Center “Nemchinovka” in 1994. The lines were previously characterized for the presence of translocations and chromosomal rearrangements cytologically and using molecular markers. Technological analyses were performed on grain obtained in Western Siberia and Moscow region. The aim of this study was to establish the possibilities of expanding the phenotypic diversity for technological properties of grain and flour as a result of such hybridization of bread wheat and the diploid cereal Aegilops speltoides. The variety ‘Rodina’ forms a vitreous grain with a high gluten content in Siberia, but has low physical properties of flour and dough. Five derived lines were found to have significantly higher protein and gluten content in grain. The highest values under both growing conditions were found in lines 73/00i, 82/00i, and 84/00i. Two lines (69/00i and 76/00i) showed a high flour strength and dough elasticity, characterizing the lines as strong and valuable in quality. These lines can be used for baking bread. Line 82/00i inherited from Ae. speltoides a soft-grain endosperm, which indicates the introgression of the Ha-Sp gene, homoeoallelic to the Ha gene of bread wheat, into ‘Rodina’. Flour of this line is suitable for the manufacture of confectionery without the use of technological additives. The lines generally retained their characteristics in different growing conditions. They can be attracted as donors of new alleles of genes that determine the technological properties of grain and resistance to biotic stresses

Interaction of genes determining the spike shape of wheat and located in 5AL chromosome

Spike parameters of hexaploid wheats from the genus Triticum L. are determined by the major genes and play an important role in systematics. Having a strong pleiotropic effect they are also have a practical importance. In this work, the interaction of the dominant genes QS and Q with the dominant gene C17648 determining a spike shape was investigated. The gene Q is situated in 5AL chromosome and determines the formation of elongated lax spike in the species T. spelta L. The homoeoallelic gene QS introgressed into bread wheat from Aegilops speltoides Tausch. and causing the formation of speltoid spike also situated in 5AL chromosome of the line 84/98w. The gene C17648 is analogous in the phenotypic manifestation to the gene C determining the formation of a dense short spike on a short culm like in T. compactum Host. It was mapped to 5AL chromosome in bread wheat line ANBW-5A and the donor of the gene was a mutant of durum wheat. In the present work, spike length, spikelet number, index of spike density and stem length were studied in F1 , F2 and F3 of three different hybrid populations. For the first time it was showed that the gene C17648 is epistatic to the dominant genes QS and Q. It was manifested in the formation of compact spike in F1 hybrids and in numerical prevalence of plants with a compact spike in F2 . At the same time, the gene C17648 showed a smaller effect on stem length and did not affected spikelet number. Using the genetic analysis it was found that the genes QS and Q are independently inherited from the gene C17648 but a substantial linkage was observed between QS or Q and b1 gene

Biological and economic characteristics of the allotetraploid with genomic formula DDAuAu from the cereal family

The synthesis  of new  allopolyploid  cereal  genotypes is an important task aimed  at involving new  genetic resources in breeding programs. Diploid species of the genera Triticum and Aegilops – bread  wheat  relatives – are an important source of agronomically  valuable traits. A tetraploid synthetic  with genomic formula DDAuAu was obtained by N.A. Navruzbekov through crossing Aegilops tauschii Coss. and Triticum urartu Thum. ex Gandil. The purpose of this work was to study  the  chromosomal composition and  biological  and  commercially  important traits of the  tetraploid. Cytogenetic analysis using fluorescent in situ hybridization  showed the  presence of all chromosomes of the D genome in the chromosomal complement of the synthetic. By means  of stepwise  vernalization, the winter habit was established for the tetraploid synthetic with the optimum vernalization requirement of 45 days. Under greenhouse conditions, two groups of genotypes were found whose flowering dates differed by 6.5 days, which may indicate an allelism at the Vrn-3 locus. The coloring of various organs of the tetraploid plant, such as coleoptile,  stem, anthers,  and glumes  of the spike, was revealed. The coloration  of the aleurone layer of the grain may indicate that the donor species T. urartu is a carrier of the Ba gene that controls its blue color. A new morphotype of leaf pubescence was found. In terms of productivity, the tetraploid is comparable to bread wheat. Grains are characterized by a supersoft structure and high wet gluten  content, from 39–45 to 65 %, in the field and greenhouse conditions, respectively. Thus, the tetraploid can be used to create  new wheat  genotypes as a source  of untapped genetic diversity, as well as a new genetic model  for studying  the patterns of evolution  of polyploid plants

Lysosomal acid lipase deficiency – an underestimated cause of hypercholesterolemia in children

Lysosomal acid lipase deficiency (LAL-D) is a rare, progressive, autosomal recessive disease, which develops due to impaired degradation and subsequent intra-lysosomal accumulation of triglycerides and cholesterol esters causing dyslipidemia. The clinical manifestations of the disease presumably depend on the residual activity of the enzyme, lysosomal acid lipase. A profound deficiency of the enzyme known as Wolman’s disease has an onset in the first 6 months of life. The disease reveals itself by dyspeptic disorders in the form of vomiting and diarrhea, lack of weight gain, hepatosplenomegaly, and adrenal calcification. If the Wolman’s disease is not treated, children die within the first 6 months as a result of exhaustion caused by malabsorption syndrome combined with progressive deterioration of liver and adrenal glands. Partial deficiency of lysosomal acid lipase manifests itself at a later age and is called cholesterol ester storage disease. Its clinical presentations include hepatosplenomegaly, elevated transaminases, hypercholesterolemia, and, in some cases, hypertriglyceridemia. Liver failure is the main cause of death in the natural course of cholesterol ester storage disease. Delayed diagnosis of the disease leads to its progression causing irreversible liver damage. The implementation of mass screening programs with the determination of cholesterol levels in childhood is critical to identifying asymptomatic patients.The article presents a clinical case of a patient aged 3 years. The molecular genetic testing showed a mutation in exon 8 of the LIPA gene: NM_000235.3:c.894G&gt;A synonymous variant in the homozygous state. It was also found that both parents of the girl had this type of mutation in the heterozygous state. The patient was prescribed sebelipase alfa in a dose of 1 mg/kg once every 14 days. The treatment was well tolerated. Due to the early verification of the diagnosis and timely pathogenetic therapy, the prognosis of the course of LAL-D, the duration and quality of life of the child were considered to be favourable.Raising the awareness of doctors along with the introduction of effective screening programs for the timely detection of dyslipidemia in children contributes to timely diagnosis and early initiation of pathogenetic therapy, which can increase the life expectancy of patients with lysosomal acid lipase deficiency and improve their quality of life

The development of a new bread wheat genotype carrying two loci for endosperm softness

The technological purpose of grain and flour wheat is largely determined by the grains endosperm structure. Its variability among wheat varieties depends mainly on the multiple allelism for a single Ha locus on chromosome 5D leading to a continuous variation of the trait. The grain endosperm can vary from hard and vitreous suitable for yeast baking to soft and floury favorable for confectionery and technical purposes. Furthermore, these traits, especially vitreousness, are strongly influenced by the growth conditions. Earlier, the Ha-Sp locus was introgessed into chromosome 5A of the bread wheat line 84/98w from Aegilops speltoides Tausch., which reduces endosperm hardness and vitreousness, like the dominant allele of the Ha locus. This paper is the first to describe the obtaining and testing of the supersoft lines combining in their genotype the homoeoallelic loci Ha-Sp of the line 84/98w and Ha of the soft grain cultivar Chinese Spring. The lines were isolated from 6–8 generations of self-pollinated F2 hybrids. They consistently exhibit a greater grain softness than the parental forms under both greenhouse and field conditions. These lines can be used in the breeding of wheat cultivars, the flour of which will not require chemical baking powder in the confectionery industry. It is also possible to use them for technical purposes for the production of bioethanol. In addition, these lines may serve as a genetic model for the study of the functional activity of homoeoallelic genes in the complex polyploid genomes of plants

Effects of limited introgressions from Triticum timopheevii Tausch. into the genome of bread wheat (Triticum aestivum L.) on physiological and biochemical traits under normal watering and drought

Alien hybridization in cereals is used for comparative investigations of genome structure and evolution as well as for extracting useful genes from the wild gene pool. The tetraploid species Triticum timopheevii has long been used as a source of genes for resistance to fungal diseases. Line 821 was developed on the genetic background of cultivar Saratovskaya 29 (S29), which is drought-resistant but is very susceptible to diseases and carries big introgressions in 2A and 2B chromosomes and a small introgression in the subtelomeric region of 5A chromosome. The two genotypes were compared for the parameters associated with direct and indirect reaction of the photosynthetic apparatus to water stress. In flag leaves of 821 line, an increased transpiration rate and stomatal conductance (1.6 times the value in optimal watering and 1.2 times the value under water deficit) and, correspondingly, reduced water use efficiency were found compared to the initial cultivar. Additionally, the actual effectiveness and electron transport rate of photosystem II and chlorophyll and carotenoid content were reduced as well as the total antioxidant capacity (approximately three-fold) under water stress. Under the same conditions, lipoxygenase activity was increased two-fold. On the whole, water deficit tolerance was decreased in the line in comparison with the parental cultivar and was accompanied by leaf senescence. Thus, it may be supposed that 2A, 2B and 5A chromosomes of the drought-tolerant cultivar S29 carry important genetic factors responsible for reaction to water stress in wheat plants

Physiological responses to water deficiency in bread wheat (Triticum aestivum L.) lines with genetically different leaf pubescence

Studying the relationship between leaf pubescence and drought resistance is important for assessing Triticum aestivum L. genetic resources. The aim of the work was to assess resistance of common wheat genotypes with different composition and allelic state of genes that determine the leaf pubescence phenotype. We compared the drought resistance wheat variety Saratovskaya 29 (S29) with densely pubescent leaves, carrying the dominant alleles of the Hl1 and Hl3 genes, and two near isogenic lines, i: S29 hl1, hl3 and i: S29 Hl2aesp, with the introgression of the additional pubescence gene from diploid species Aegilops speltoides. Under controlled conditions of the climatic chamber, the photosynthetic pigments content, the activity of ascorbate-glutathione cycle enzymes and also the parameters of chlorophyll fluorescence used to assess the physiological state of the plants photosynthetic apparatus were studied in the leaves of S29 and the lines. Tolerance was evaluated using the comprehensive index D, calculated on the basis of the studied physiological characteristics. The recessive state of pubescence genes, as well as the introduction of the additional Hl2aesp gene, led to a 6-fold decrease in D. Under the water deficit influence, the fluorescence parameters profile changed in the lines, and the viability index decreased compared with S29. Under drought, the activity of ascorbate peroxidase, glutathione reductase and dehydroascorbate reductase in the line i: S29 hl1, hl3 decreased 1.9, 3.3 and 2.3 times, in the line i: S29 Hl2aesp it decreased 1.8, 3.6 and 1.8 times respectively, compared with S29. In a hydroponic greenhouse, line productivity was studied. Compared with S29, the thousand grains mass in the line i: S29 hl1, hl3 under water deficit was reduced. The productivity of the line i: S29 Hl2aesp was significantly reduced regardless of water supply conditions in comparison with S29. Presumably, the revealed effects are associated with violations of cross-regulatory interactions between the proteins of the trichome formation network and transcription factors that regulate plant growth and stress response