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.
The improvement of phenotyping methods is necessary for large-scale screening studies of wheat (Triticum aestivum L.) drought tolerance. The objective of our research was to find out whether it is ...possible to use chlorophyll (Chl) fluorescence parameters instead of biochemical indicators of drought tolerance when screening wheat. We measured shoot biomass, gas exchange, as well as biochemical and Chl fluorescence indicators in 11 wheat genotypes grown under contrasting water supplies and differing in drought tolerance. The effect of drought on the traits was evaluated using the effect of size index. We made two independent rankings: one based on biochemical indicators and the other on Chl fluorescence parameters. The positions of the three genotypes with the highest comprehensive drought tolerance index in the two independent rankings coincided completely. It is concluded that Chl fluorescence methods are suitable for identifying soft wheat genotypes that differ significantly in their ability to activate cellular defense mechanisms.
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 73/00
, 82/00
, and 84/00
. Two lines (69/00
and 76/00
) 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 82/00
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.
Leaves of many angiosperm species develop trichomes. These epidermal outgrowths have been exploited to the study the determination of cell fate, plant cell differentiation mechanisms and cell ...morphogenesis in the model plant species. It was found that even simple shape trichomes (leaf hairs) offer protection against both biotic and abiotic stress factors. Currently, in monocotyledonous plants, the genetic basis of leaf hair formation is poorly understood. This study sought to establish the genetic control of leaf pubescence formation in bread wheat (Triticum aestivum L.) in terms of leaf hair patterning and growth. A set of cultivars and lines carrying allelic combinations of three pubescence controlling genes, Hl1, Hl3 and Hl2 ᵃᵉˢᵖ was used for quantitative phenotyping. It was demonstrated that these genes differ in their effect on leaf hair formation: Hl1 and Hl3 more affected leaf hair initiation and growth, while Hl2 ᵃᵉˢᵖ modified leaf hair length. Their action was independent to a large extent. A model of Hl1, Hl3 and Hl2 ᵃᵉˢᵖ genes action is proposed.
The end use and value of bread wheat grain is determined by its protein and gluten content. Therefore, stable manifestation of this trait in a cultivar is an important breeding goal. According to ...some reports, the tetraploid species
T. timopheevii
is characterized by high grain protein and gluten contents. However, there is no example of the transfer of genes for these traits from this species to common wheat. The aim of this study was to transfer chromosome 2A with an introgression from
T. timopheevii
from an experimental line (Line 821) to the bread wheat cultivar Saratovskaya 29 (S29) and to show its association with increased protein and gluten contents in grain. Chromosome 2A from Line 821 was transferred to cv. S29 by means of chromosome substitution, and its integrity was checked using 14 molecular markers. Substitution line S29(821 2A) was grown at 5 different locations: Novosibirsk, Omsk, Barnaul, Ussuriysk and Gatersleben, and in a greenhouse. The protein and gluten contents in the grain of S29(821 2A) produced under all conditions were significantly higher by 1–2% and 3–4%, respectively, than in the parental cultivar. In most cases, this introgression did not reduce grain yield and retained thousand grain weight. Substitution line S29(821 2A) had high rheological properties of dough comparable to the high-quality cv. S29. The new genetic factor might belong to the homoeoallelic series
Gpc-2
for high grain protein content.
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.
Background.The end-use of the bread wheat grain depends on the endosperm properties determined by the alleles of the Pinaand Pinbgenes at the Halocus 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 speltoidesTausch, 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 Haand HaSpin 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 Halocus, with the introgressive line 84/98w, carrier of the Ha-Splocus, 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.
Two major genes controlling leaf pubescence were mapped on chromosomes 4BL (Hl1) and 7BS (Hl2 (Aesp) ) in wheat (Saratovskaya 29) and a wheat/Aegilops introgression line (102/00(I)), respectively, ...together with quantitative trait loci (QTLs) determining hairiness of the leaf margin (QHl.ipk-4B, QHl.ipk-4D) and auricle (QPa.ipk-4B, QPa.ipk-4D) on the long arms of chromosomes 4B and 4D, respectively. The QTLs on chromosome 4D were contributed by a synthetic wheat and, therefore, originated from Aegilops tauschii. The homoeologous group 4 wheat/A. tauschii genes/QTLs detected in the present study were aligned with the barley pubescence genes Hln/Hsh and Hs(b) and the hairy peduncle rye gene Hp1. The locus seems to be pleiotropically responsible for the pubescence of different plant organs in different species of the Triticeae. Another homoeologous series may be present on the short arms of the homoeologous group 7 chromosomes, based on the results of an allelic test cross between the Chinese local cultivar Hong-mang-mai carrying Hl2 and the wheat/Aegilops speltoides introgression line 102/00(I).
The presence of the allele Rc-A1b on chromosome 7A specified the expression profile of the F3h-1 (encoding flavanone 3-hydroxylase) genes and anthocyanin pigmentation in coleoptiles of Russian bread ...wheat cultivar ‘Saratovskaya 29'. A quantitative RT-PCR analysis compared the temporal expression profile of F3h-A1, F3h-B1, and F3h-D1 in the coleoptiles of ‘Saratovskaya 29' and the standard cytogenetic stock ‘Chinese Spring' (‘Hope' 7A), both of which carry Rc-A1b. There was no within-genotype variation for expression level of the F3h-1 homoeologues at any of the sampling times, but the expression profiles varied markedly between the two genotypes. This result suggested that there may be functional allelic diversity at Rc-A1, which affects the transcription of the F3h-1 genes in colored coleoptiles. Microsatellite-based genetic mapping was used to locate Rc-A1 along with the new loci Pc-A1 (purple culm), Plb-A1 (purple leaf blade), and Pls-A1 (purple leaf sheath) in a single cluster on the short arm of chromosome 7A.
Phenomics is a field of science at the junction of biology and informatics which solves the problems of rapid, accurate estimation of the plant phenotype; it was rapidly developed because of the need ...to analyze phenotypic characteristics in large scale genetic and breeding experiments in plants. It is based on using the methods of computer image analysis and integration of biological data. Owing to automation, new approaches make it possible to considerably accelerate the process of estimating the characteristics of a phenotype, to increase its accuracy, and to remove a subjectivism (inherent to humans). The main technologies of high-throughput plant phenotyping in both controlled and field conditions, their advantages and disadvantages, and also the prospects of their use for the efficient solution of problems of plant genetics and breeding are presented in the review.
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