Kinematic characteristics of the car movement from the top to the calculation point of the marshalling hump

Introduce analytical acceleration formulas that are derived from the classic d'Alembert principle of theoretical mechanics for high-speed sections and sections of retarder positions; show the possibility of determining the instantaneous car speeds in each section of the marshalling hump according to the formulas of elementary physics both for high-speed sections and for sections of retarder positions; provide formulas for determining the time of movement of a car with uniformly accelerated and/or uniformly retarded motion of the car on the inclined part of the hump, as well as in areas of retarder positions. Research methods: The classic d'Alembert principle of theoretical mechanics is widely used in the paper. Main results: For the first time, the results of constructing a graphical dependence of the estimated height of the marshalling hump over the entire length of its profile are presented in the form of a decrease in the profile height of each section of the inclined part in proportion to the slope of the track. The results of constructing graphical dependences on changes in the speed and time of movement of a car along the entire length of the inclined part of the marshalling hump are fundamentally different from the existing methodology, where, for example, curves of medium (rather than instantaneous) speeds of a car are built. The proposed new methodology for calculating the kinematic characteristics of the car movement along the entire length of the hump allows an analysis of the mode of shunting car at the marshalling humps

Using of Genome Editing Methods in Plant Breeding

The main task of plant breeding is creating of high-yield, resistant to biotic and abiotic stresses crop varieties with high product quality. The using of traditional breeding methods is limited by the duration of the new crop varieties creation with the required agronomic traits. This depends not only on the duration of growing season and reaching of mature stage of plants (especially the long-period growth plants, e.g. trees), as well as is associated with applying of multiple stages of crossing, selection and testing in breeding process. In addition, conventional methods of chemical and physical mutagenesis do not allow targeting effect to genome. However, the introduction of modern DNA-technology methods, such as genome editing, has opened in a new era in plant breeding. These methods allow to carry out precise and efficient targeted genome modifications, significantly reducing the time required to get plants with desirable features to create new crop varieties in perspective. This review provides the knowledge about application of genome editing methods to increase crop yields and product quality, as well as crop resistance to biotic and abiotic stresses. In addition, future prospects for integrating these technologies into crop breeding strategies are also discussed

Development, genetic mapping and QTL association of cotton PHYA, PHYB, and HY5-specific CAPS and dCAPS markers

BACKGROUND: Among SNP markers that become increasingly valuable in molecular breeding of crop plants are the CAPS and dCAPS markers derived from the genes of interest. To date, the number of such gene-based markers is small in polyploid crop plants such as allotetraploid cotton that has A- and D-sub-genomes. The objective of this study was to develop and map new CAPS and dCAPS markers for cotton developmental-regulatory genes that are important in plant breeding programs. RESULTS: Gossypium hirsutum and G. barbadense, are the two cultivated allotetraploid cotton species. These have distinct fiber quality and other agronomic traits. Using comparative sequence analysis of characterized GSTs of the PHYA1, PHYB, and HY5 genes of G. hirsutum and G. barbadense one PHYA1-specific Mbo I/Dpn II CAPS, one PHYB-specific Alu I dCAPS, and one HY5-specific Hinf I dCAPS cotton markers were developed. These markers have successfully differentiated the two allotetraploid genomes (AD(1) and AD(2)) when tested in parental genotypes of ‘Texas Marker-1’ (‘TM-1’), ‘Pima 3–79’ and their F(1) hybrids. The genetic mapping and chromosome substitution line-based deletion analyses revealed that PHYA1 gene is located in A-sub-genome chromosome 11, PHYB gene is in A-sub-genome chromosome 10, and HY5 gene is in D-sub-genome chromosome 24, on the reference ‘TM-1’ x ‘Pima 3–79’ RIL genetic map. Further, it was found that genetic linkage map regions containing phytochrome and HY5-specific markers were associated with major fiber quality and flowering time traits in previously published QTL mapping studies. CONCLUSION: This study detailed the genome mapping of three cotton phytochrome genes with newly developed CAPS and dCAPS markers. The proximity of these loci to fiber quality and other cotton QTL was demonstrated in two A-subgenome and one D-subgenome chromosomes. These candidate gene markers will be valuable for marker-assisted selection (MAS) programs to rapidly introgress G. barbadense phytochromes and/or HY5 gene (s) into G. hirsutum cotton genotypes or vice versa. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12863-016-0448-4) contains supplementary material, which is available to authorized users

Cotton as a Model for Polyploidy and Fiber Development Study

Cotton is one of the most important crops in the world. The Gossypium genus is represented by 50 species, divided into two levels of ploidy: diploid (2n = 26) and tetraploid (2n = 52). This diversity of Gossypium species provides an ideal model for studying the evolution and domestication of polyploids. In this regard, studies of the origin and evolution of polyploid cotton species are crucial for understanding the ways and mechanisms of gene and genome evolution. In addition, studies of polyploidization of the cotton genome will allow to more accurately determine the localization of QTLs that determine fiber quality. In addition, due to the fact that cotton fibers are single trichomes originating from epidermal cells, they are one of the most favorable model systems for studying the molecular mechanisms of regulation of cell and cell wall elongation, as well as cellulose biosynthesis

Genome Editing in Plants: An Overview of Tools and Applications

The emergence of genome manipulation methods promises a real revolution in biotechnology and genetic engineering. Targeted editing of the genomes of living organisms not only permits investigations into the understanding of the fundamental basis of biological systems but also allows addressing a wide range of goals towards improving productivity and quality of crops. This includes the creation of plants with valuable compositional properties and with traits that confer resistance to various biotic and abiotic stresses. During the past few years, several novel genome editing systems have been developed; these include zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats/Cas9 (CRISPR/Cas9). These exciting new methods, briefly reviewed herein, have proved themselves as effective and reliable tools for the genetic improvement of plants

Recent Developments in Fiber Genomics of Tetraploid Cotton Species

Cotton (Gossypium spp.) produces naturally soft, single-celled trichomes as fiber on the seed coat supplying the main source of natural raw material for the textile industry. It is economically considered as one of the most leading cash crops in the world and evolutionarily very important as a model system for detailed scientific investigations. Cotton production is going through a big transition stage such as losing the market share in competition with the synthetic fibers, high popularity of Bt and herbicide resistance genes in cotton cultivars, and the recent shift of fiber demands to meet the standard fiber quality due to change of textile technologies to produce high superior quality of fibers in the global market. Recently, next-generation sequencing technologies through high-throughput sequencing at greatly reduced costs provided opportunities to sequence the diploid and tetraploid cotton genomes. With the availability of large volume of literatures on molecular mapping, new genomic resources, characterization of cotton genomes, discoveries of many novel genes, regulatory elements including small and microRNAs and new genetic tools such as gene silencing or gene editing technique for genome manipulation, this report attempted to provide the readers a comprehensive review on the recent advances of cotton fiber genomics research

RNA Interference for Functional Genomics and Improvement of Cotton (Gossypium sp.)

RNA interference (RNAi), is a powerful new technology in the discovery of genetic sequence functions, and has become a valuable tool for functional genomics of cotton (Gossypium ssp.). The rapid adoption of RNAi has replaced previous antisense technology. RNAi has aided in the discovery of function and biological roles of many key cotton genes involved in fiber development, fertility and somatic embryogenesis, resistance to important biotic and abiotic stresses, and oil and seed quality improvements as well as the key agronomic traits including yield and maturity. Here, we have comparatively reviewed seminal research efforts in previously used antisense approaches and currently applied breakthrough RNAi studies in cotton, analyzing developed RNAi methodologies, achievements, limitations, and future needs in functional characterizations of cotton genes. We also highlighted needed efforts in the development of RNAi-based cotton cultivars, and their safety and risk assessment, small and large-scale field trials, and commercialisation