Conventional Hybridization Research Articles

Molecular Breeding of a Novel PTGMS Line of WDR for Broad-Spectrum Resistance to Blast Using Pi9, Pi5, and Pi54 Genes

BackgroundThe two-line method based on the photoperiod and thermo-sensitive genic male sterile (PTGMS) lines is more cost-effective, simple, and efficient than the three-line system based on cytoplasmic male-sterility. Blast and drought are the most prevalent biotic and abiotic stress factors hampering rice production. Molecular techniques demonstrate higher efficacy in the pyramiding of disease resistance genes, providing green performance under the background of water-saving and drought-resistance rice.ResultsThis study employed molecular marker-assisted selection, conventional hybridization, and high-intensity stress screening to integrate three broad-spectrum blast resistance genes Pi9, Pi5, and Pi54 into Huhan 1S. Subsequently, a novel water-saving and drought-resistance rice (WDR) PTGMS line Huhan 74S was developed. The drought resistance of the new PTGMS line Huhan 74S was comparable to that of Huhan 1S. Pathogenicity assays involving the inoculation of 14 blast prevalent isolates in the glasshouse showed that the blast resistance frequency of Huhan 74S was 85.7%. Further evaluation under natural blast epidemic field conditions showed that Huhan 74S and its hybrids were resistant to leaf and neck blast. The critical temperature point of fertility-sterility alteration of Huhan 74S was 23 °C daily mean temperature. The complete male sterility under natural growth conditions in 2017 at Shanghai lasted for 67 days. Also, both the agronomic and grain quality traits met the requirement for two-line hybrid rice production.ConclusionThese results indicate that the newly bred PTGMS line Huhan 74S can be used to breed high-yielding, good-quality, disease-resistant two-line hybrid water-saving and drought-resistance rice (WDR), hence promoting sustainable rice production in China.

β-Lactam Resistance Gene NDM-1 in the Aquatic Environment: A Review.

New Delhi Metallo-β-lactamase-1 (NDM-1) offers carbapenem antibiotics resistance that creates an evolving challenge in treating bacterial infections. NDM-1-bearing strains were observed in surface waters around New Delhi in 2010 and after then identified globally. The usage of antibiotics may hasten the growth of the NDM-1-producing bacteria, which pose severe hazards to human and animal health. The emergence of the NDM-1 in the aquatic environment is turning out to be a growing concern worldwide. NDM-1 gene conferring resistance to a widespread class of antibiotics has been observed in bacteria disseminated in animal production wastewaters, hospital sewage, domestic sewage, industrial effluents, wastewater treatment plants, drinking water, surface water, and even in groundwater. This review recapitulates the currently published research studies on the prevalence and geographical distribution of the NDM-1 gene in the aquatic environment, its habitats, and healthcare risk associated with NDM-1-producing bacteria, in addition to molecular techniques employed to reveal the occurrence of the NDM-1 in the aquatic environment, including conventional polymerase chain reaction, real-time qPCR, DNA hybridization, and microarray-based methods.

The Effect of 5-Azacitidine Treatment on the Biologic Characteristics of Bone Marrow Mesenchymal Stem Cells in Patients with Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are clonal disorders of the hematopoietic stem cell characterized by ineffective bone marrow (BM) hematopoiesis and increased risk for leukemic evolution. An abnormal BM microenvironment has been reported to contribute to BM failure in MDS through defective support of hematopoiesis. The cellular elements of the BM microenvironment derive from a common progenitor cell, namely the mesenchymal stem cell (MSC). We have previously shown that MSCs from MDS patients display impaired proliferative and clonogenic potential and develop chromosomal alterations during passages.It has been shown that DNA methylation occurs at a high frequency in MDS and that gene reactivation by hypo-methylating agents may have a positive impact on patients' outcome. Recent evidence also suggests altered global DNA methylation status in BM-MSCs of MDS patients. The methyl transferase inhibitor 5-Azacitidine (ΑΖΑ) is widely used for the treatment of MDS; however the effect of AZA on patients' BM microenvironment and specifically on the MSC compartment has not been extensively studied. In the present study we investigate the functional, molecular and cytogenetic characteristics of ex vivo expanded BM-MSCs from MDS patients receiving AZA, before and after 6-cycle therapy.MSCs were isolated and expanded from 14 patients with high risk MDS and 10 age- and sex-matched hematologically healthy subjects undergoing surgery for hip replacement, after informed consent. MSCs were expanded and re-seeded for a total of 5 passages (P) and phenotypically characterized by flow cytometry. MSCs were induced to differentiate to adipocytes and osteoblasts. Differentiation was assessed by cytochemical stains and by the expression of adipocyte- and osteocyte-specific genes. MSC growth characteristics were assessed by the population doubling time (PDT) and the methyl-triazolyl-tetrazolium (MTT) assay throughout passages. The clonogenic potential of MSCs was evaluated by the colony forming unit fibroblast assay. Conventional cytogenetic and array comparative genomic hybridization (aCGH) analyses were performed in cultured expanded MSCs at P2.MSCs from MDS patients before and after therapy, displayed normal spindle-shape morphology and immunophenotypic characteristics as shown by the expression of CD90, CD105, CD44, CD29, CD73, and the lack of expression of CD45, CD14 and CD34. MSCs were also able to differentiate into adipocytes and osteoblasts before and after therapy, as evidenced by the Oil Red O and Alizarin Red staining, respectively, and the expression of differentiation specific genes. Cumulative analysis showed that the proliferation potential of patient MSCs, evaluated by the PDT and MTT assays, was statistically significant decreased compared to healthy individuals (P<0.01) but increased significantly following AZA treatment compared to baseline (P<0.05), although not at the level of the healthy controls. A paired analysis of patient samples before and after therapy, also showed that AZA treatment improves significantly the proliferation rate of MDS-MSCs (P<0.05). Similarly, a cumulative and paired analysis showed that the defective (compared to healthy individuals) clonogenic potential of patient MSCs at P2, increased significantly following AZA treatment (P<0.05 and P<0.05, respectively), although not at the level of the healthy individuals. Karyotypic analysis did not reveal any chromosomal abnormalities in MSC samples, before or after AZA treatment. An aCGH analysis of P2 MSCs has - thus far - been performed in three MDS patients before and after AZA therapy. Results have indicated genetic abnormalities (duplications/deletions) in all three samples before treatment that remained unchanged after AZA therapy whereas some new abnormalities also appeared.The data of this ongoing study on the biological properties of MSCs from MDS patients receiving AZA, show an improvement of the clonogenic and proliferative potential of MSCs following treatment. According to aCGH analysis, the genetic abnormalities of MSCs remain unaffected. The findings of the functional and cytogenetic characteristics of patient MSCs before and after therapy will be individually correlated with the MSC methylation status and with patients' outcome and the results are anticipated to provide novel insights in the role of AZA therapy in the BM microenvironment of MDS patients. DisclosuresNo relevant conflicts of interest to declare.

Hepatitis A related to foods

Hepatitis A is caused by hepatitis A virus (HAV). Hepatitis A virus (HAV) is classified as a picornavirus. Hepatitis A virus infection occurs globally and is causing a public health concern, primarily in developing countries due to its persistent circulation in the environment. The improved sanitary condition and increase in awareness of personal hygiene have led to the marked reduction of HAV prevalence in industrialized countries during childhood and to a shift of the infection towards adulthood. HAV is an environmentally stable, positive single stranded RNA virus that is primarily transmitted by the fecal-oral route, person to person contact or ingestion of contaminated food and drink. One of the main causes leading to HAV infection is epidemiologically linked to the consumption of raw or undercooked shellfish particularly oysters and clams. Due to their filter-feeding style, these shellfishes readily concentrate viruses from the surrounding water containing municipal sewage, and as a consequence pose a health threat to consumers. Therefore, development of detection techniques possessing the requisite sensitivity and specificity for the practical routine monitoring purposes is of great importance necessary for the protection of shellfish-consuming public. Nucleic acid based method such as reverse transcription PCR has emerged as the popular method of choice in view of rapidity, accuracy and sensitivity in contrary of the time-consuming conventional cell culture and hybridization techniques. The low concentration of viral genome present in the environmental sample which requires effective isolation and concentration of virions and the labor-extensive purification, removal of PCR inhibitors will be unfavorable

Challenges in Tick-Borne Pathogen Detection: The Case for Babesia spp. Identification in the Tick Vector.

The causative agents of Babesiosis are intraerythrocytic protozoa of the genus Babesia. Babesia parasites are present around the world, affecting several mammals including humans, pets and livestock, hence its medical and veterinary relevance. Babesia spp. detection in its invertebrate host is a main point in understanding the biology of the parasite to acquire more knowledge on the host–Babesia–vector interactions, as increasing knowledge of the Babesia lifecycle and babesiosis epidemiology can help prevent babesiosis outbreaks in susceptible mammals. The aim of the present review is to highlight the newest findings in this field, based on a bibliographic compilation of research studies recently carried out for the detection of the main Babesia species found in tick vectors affecting mammalian hosts, including the different tick stages such as adult ticks, larvae, nymphs and eggs, as well as the detection method implemented: microscopic tools for parasite identification and molecular tools for parasite DNA detection by conventional PCR, nested-PCR, PCR-RFLP, PCR-RLB hybridization, real time-PCR, LAMP and RAP assays. Although molecular identification of Babesia parasites has been achieved in several tick species and tissue samples, it is still necessary to carry out transmission experiments through biological models to confirm the vectorial capacity of various tick species.

Spin and orbital properties of perpendicular magnetic anisotropy for spin-orbit torque material devices

Computer engineers have been attempting to incorporate spin-based devices in future computer architectures, such as processing-in-memory (PIM) in artificial intelligence systems. A successful PIM requires ongoing efforts for developing fast and low-power spintronic material devices. The spin-orbit torque (SOT) device, which is associated with perpendicular magnetic anisotropy (PMA) materials, is a promising candidate. Herein, macroscopic and nanoscopic studies on the spin-orbit interaction of two distinct SOT-PMA systems are conducted to enhance our understanding of the interfacial PMA and pave the way of material design for reliable and high-performance spin memory and logic devices. The experimental results indicate that further theoretical studies are needed to establish a sophisticated explanation instead of the conventional hybridization for the interfacial PMA. In addition, an interesting phenomenon, which can be a useful ingredient while applying thermal energy barrier, concerning the integration of reliable spin devices in future commercial computer systems is reported.

Human Papilloma Virus Frequency and Genotypes; Evaluation of the 4879 Screenings Made with Polymerase Chain Reaction and Chip Array Between 2001 and 2019 in Istanbul.

Objectives:The aim of this study is the documentation of human papilloma virus (HPV) frequency and types seen in the city of Istanbul, Turkey, as well as evaluation of the relationship between these subtypes and cytological and pathological diagnoses.Methods:4879 cases were studied in our molecular pathology department between 2001 and 2019 in Istanbul. Between 2001 and 2010, 1692 cases were screened for HPV 6, 11, 16, 18, 31, and 33 by conventional hybridization and polymerase chain reaction (PCR). Since 2011, up to 49 HPV typing has been performed for 3187 cases with chip array. The cases were referred to the pathology center and the hospital pathology department by clinicians for screening before HPV vaccination and on the observation of precancerous changes and koilocyts in cytological-histopathological evaluations.Results:In this study, the frequency of HPV was found to be 10.8% (527 HPV-positive cases). Among these, 348 cases were high-risk groups, whether or not they were previously associated with a low-risk group. When we look at the distribution of the cases according to the high-risk HPV types, HPV 16 is the most common type. The frequencies of occurrence of other HPV types are as following: HPV–16: 41.7%, HPV–31: 11.7%, HPV–52: 7.9%, HPV–51: 7.1%, HPV–33: 6.9%, HPV–45: 6.5%, HPV–18: 6.3%, HPV–39: 6.1%, and HPV–58: 5.8%. It was further found that multiple infections were 28% of high grade squamous intraepithelial lesion cases. HPV frequency was 38% and 72%, respectively, in cases with cytologically or histopathological precancerous, low-grade squamous intraepithelial lesion, and HSIL changes. As a final note, HPV was detected in 9 of 10 cases with cervical cancer (90%). Only 1 adenocarcinoma case detected in the series was a double infection with HPV types 18 and 45.Conclusion:HPV 16 was the most common type found in this study. It is followed by types 31, 52, 51, 33, 45, 18, 39, and 58, respectively. The most common association observed in double infections was between HPV 16 and 58. It was also observed that the incidence of HPV in the city of Istanbul, Turkey, was similar to other developed countries. As a final note, in addition to screening tests, PCR and chip array studies should be conducted and the community should be informed about preventive medicine and the importance of condom use.

Advances in the Detection of Toxic Algae Using Electrochemical Biosensors.

Harmful algal blooms (HABs) are more frequent as climate changes and tropical toxic species move northward, especially along the Iberian Peninsula, a rich aquaculture area. Monitoring programs, detecting the presence of toxic algae before they bloom, are of paramount importance to protect ecosystems, aquaculture, human health and local economies. Rapid, reliable species identification methods using molecular barcodes coupled to biosensor detection tools have received increasing attention as an alternative to the legally required but impractical microscopic counting-based techniques. Our electrochemical detection system has improved, moving from conventional sandwich hybridization protocols using different redox mediators and signal probes with different labels to a novel strategy involving the recognition of RNA heteroduplexes by antibodies further labelled with bacterial antibody binding proteins conjugated with multiple enzyme molecules. Each change has increased sensitivity. A 150-fold signal increase has been produced with our newest protocol using magnetic microbeads (MBs) and amperometric detection at screen-printed carbon electrodes (SPCEs) to detect the target RNA of toxic species. We can detect as few as 10 cells L−1 for some species by using a fast (~2 h), simple (PCR-free) and cheap methodology (~2 EUR/determination) that will allow this methodology to be integrated into easy-to-use portable systems.

Zippering DNA Tetrahedral Hyperlink for Ultrasensitive Electrochemical MicroRNA Detection.

Pluripotency of a DNA tetrahedron (DNATT) has made the iconic framework a compelling keystone in biosensors and biodevices. Herein, distinct from the well-tapped applications in substrate fabrication, we focus on exploring their tracing and signaling potentials. A homologous family of four isostructural DNATT, i.e., DNATTα/β/γ/δ, was engineered to form a sensor circuitry, in which a target-specific monolayer of thiolated DNATTγ pinned down the analyte jointly with the reciprocal DNATTδ into a sandwich complex; the latter further rallied an in situ interdigital relay of biotinylated DNATTα/β into a microsized hyperlink dubbed polyDNATT. Its scale and growth factors were illuminated rudimentarily in transmission electron microscopy and confocal laser scanning microscopy. Using a nonsmall-cell lung cancer-related microRNA (hsa-miR-193a-3p) as the subject, a compound DNA-backboned construct was synthesized, fusing all building blocks together. Its superb tacticity and stereochemical conformality avail the templating of a horseradish peroxidase train, which boosted the paralleled catalytic surge of proton donors, resulting in an attomolar detection limit and a broad calibration range of more than seven orders of magnitude. Such oligomerization bested the conventional hybridization chain reaction laddering at both biomechanical stability and stoichiometric congruency. More significantly, it demonstrates the flexibility of DNA architectures and their multitasking ability in biosensing.

Inverse design of a single-step-etched ultracompact silicon polarization rotator.

We propose and experimentally demonstrate a novel ultracompact silicon polarization rotator based on equivalent asymmetric waveguide cross section in only single-step etching procedure for densely integrated on-chip mode-division multiplexing system. In the conventional mode hybridization scheme, the asymmetric waveguide cross section is employed to excite the hybridized modes to realize high performance polarization rotator with compact footprint and high polarization extinction ratio. However, the fabrication complexity severely restricts the potential application of asymmetric waveguide cross section. We use inverse-designed photonic-crystal-like subwavelength structure to realize an equivalent asymmetric waveguide cross section, which can be fabricated in only single-step etching process. Besides, a theory-assisted inverse design method based on a manually-set initial pattern is employed to optimize the device to improve design efficiency and device perform. The fabricated device exhibited high performance with a compact footprint of only 1.2 × 7.2 µm2, high extinction ratio (> 19 dB) and low insertion loss (< 0.7 dB) from 1530 to 1590 nm.

Organs infected with Trypanosoma cruzi and DTU identification in the naturally infected rodent Octodon degus

Chagas disease is a public health problem in America. Its parasite, Trypanosoma cruzi, presents different discrete typing units (DTUs), colonizes organs of mammalian hosts in chronic infections, and presents tropism for particular organs in experimental infections. We evaluated T. cruzi tropism towards organs on the naturally infected rodent Octodon degus, identifying the parasites’ DTUs, by means of conventional PCR and hybridization. Almost all the analyzed organs presented T. cruzi. More than 42% of the tested oesophagus, skin, skeletal muscle, brain and intestine showed T. cruzi DNA. Other nine types of organs were infected in over 15%. These results suggest that there is some tropism by T. cruzi in chronically infected O. degus. DTU TcV was present in 92.5% of infected organs with identified DTUs; this DTU is frequently reported in human infections in the Southern Cone of South America. Few organs showed mixed DTU infections. This is one of the few reports on the outcome of chronic natural T. cruzi-infection in wild mammal hosts exposed to naturally infected vectors.

Studies on Induction of Somaclonal Variation in Sugarcane (Saccharum officinarum) and Validation of Mutant Using Molecular Markers

Sugarcane is a perennial grass of the family Poaceae, primarily cultivated for its juice from which sugar is processed. Sugarcane yields are declining due to varietal degeneration and susceptibility to biotic and abiotic stresses. Smut of sugarcane is one of them, the disease can cause significant losses in cane tonnage and juice quality. As development of superior sugarcane varieties through conventional hybridization program is time consuming and has the problem of transfer of undesirable characters/traits into the newly developed hybrids/variety. In this connection, attempts were made to introduce genetic variability in sugarcane by in vitro culture techniques and mutation breeding. Induction of somaclonal variation is one of them which is described as the genetic variability present among cultured cells, plants derived from such cells or progeny of such plants. The treatment, MS medium supplemented with 3 mgl−1 2, 4-D found most suitable for callus induction and multiplication. The callus on application of EMS become pinkish brown in colour, shoot regeneration from callus cells was high in MS medium supplemented with 3 mgl−1 BAP gave dark gray or brown and sticky callus. Molecular analysis of somaclonal mutants showed by primers polymorphism of DNA bands on validating with molecular markers viz. RAPD and ISSR markers gave 100 per cent polymorphism by two RAPD primers named OPA-01 and OPA-02 showed that out of 17 DNA samples of mutants considered, all were showing variations but one DNA sample was showing similarity with mother plant. The present investigation reports the study induction of somaclonal variation in Sugarcane (Saccharum officinarum) and validation of mutant using molecular markers in variety Co261.

An in vitro screening system to assess aluminum toxicity in sugarcane (Saccharum spp.) cultivars

Mutagenic breeding is an approach being developed especially for those characteristics that are not inherited through conventional genetic hybridization. Soil acidity and aluminum (Al3+) toxicity limit sugarcane production, particularly in leached soils in the coastal cultivation regions in South Africa. An in vitro screening procedure was developed based on plantlet re-rooting in Al3+-containing medium to select putative Al3+ tolerant variants produced by induced mutagenesis. A preliminary test did not show any difference among three cultivars in their ability to re-root in the presence of Al3+. Subsequent work focused on Saccharum sp. ‘NCo376’ and two Al3+ concentrations (15 and 45 mM), representing LC50 and LC90 re-rooting inhibition. In an attempt to increase the stringency of the selection conditions, the possible effects of inorganic nitrogen (N) forms in the culture media on Al3+ toxicity were investigated. The form of N affected root regrowth and citrate exudation. Sugarcane plantlets showed an uptake preference for ammonium (NH4+) over nitrate (NO3−), and 10 and 20 mM NH4+ appeared to alleviate Al3+ toxicity compared with NO3−. Although in agricultural soils NO3− is the dominant form of N, it can readily leach into the sub-soil, in which deep roots encounter Al3+ toxicity in the presence of NO3−. Therefore, the ability to withstand the toxic effects of Al3+ in the presence of NO3− could be beneficial for N use efficiency and access to water at depths during drought.

Survivorship of wild caught Mepraia spinolai nymphs: The effect of seasonality and Trypanosoma cruzi infection after feeding and fasting in the laboratory

Chagas disease is caused by Trypanosoma cruzi. Vector survival is an important variable affecting vectorial capacity to determine parasite transmission risk. The aims of this study are to evaluate vector survival under fasting/starvation conditions of wild-caught Mepraia spinolai after feeding and fasting, the pathogenicity of T. cruzi infection, the parasite burden and seasonal variation in parasite discrete typing units (DTU). The survivorship of M. spinolai nymphs after two continuous artificial feedings was evaluated, assessing their infection with microscopic observation of fecal samples and PCR. Later, insects were fasted/starved until death. We performed qPCR analyses of parasite load in the fecal samples and dead specimens. T. cruzi genotyping was performed using conventional PCR amplicons and hybridization tests. Infection rate was higher in M. spinolai nymphs in summer and spring than in fall. Parasite burden varied from 3 to 250,000 parasites/drop. Survival rate for starved nymph stage II was lower in insects collected in the spring compared to summer and fall. TcII was the most frequent DTU. Mainly metacyclic trypomastigotes were excreted. We conclude that M. spinolai infection rate in nymphs varies among seasons, suggesting higher transmission risk in warmer seasons. However, nymphs stage II collected in spring are more sensitive to starvation compared to other seasons. TcII in single or mixed infection does not seem relevant to determine vector pathogenicity. These results of vector survivorship after fasting/starvation are important to determine the competence of M. spinolai as a vector of T. cruzi, since they excrete metacyclic trypomastigotes and the parasitism with T. cruzi seems to be poorly pathogenic to the vector under a severe fasting/starvation condition.

Runs of homozygosity in spontaneous abortions from families with recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a severe reproductive pathology with a significant component of unexplained etiology. Extended homozygous regions as a possible etiological factor for RPL were sought in the genomes of embryos. Twenty-two paired first-trimester spontaneously aborted embryos from eleven women with recurrent miscarriage were analyzed. All embryos had normal karyotypes according to metaphase karyotyping and conventional comparative genomic hybridization. SurePrint G3 Human CGH + SNP 4 × 180K microarrays (Agilent Technologies) were used to search for homozygous regions. As a result, 39 runs of homozygosity (ROH) were identified in extraembryonic tissues of 15 abortuses. Verification of recurrent homozygous regions was performed by Sanger sequencing. The presence of occasional heterozygous SNPs was shown in 25 extended ROHs, which may indicate that they did not arise de novo but were inherited from parents. In the course of inheritance in a series of generations, they may accumulate mutations, leading to heterozygosity for several sites in the initially homozygous population-specific regions. Homozygotization of recessive mutations is one of the putative mechanisms of the influence of such inherited ROHs on RPL development. The high frequency of extended ROHs detected in the present study may point to a role of inbreeding in RPL etiology. Homozygous regions may also occur due to uniparental disomy, and abnormalities of genomic imprinting may be another mechanism responsible for the pathological manifestation of ROHs in embryogenesis. Indeed, five predicted imprinted genes were identified within ROHs according to the Geneimprint database: OBSCN, HIST3H2BB, LMX1B, CELF4, and FAM59A. This work reports the first finding of a high frequency of extended ROHs in spontaneously aborted embryos with normal karyotypes from families with RPL.

Investigating Transgene Integration and Organization in Cotton (Gossypium hirsutum L.) Genome.

In this chapter, we present detailed experimental procedures for investigating integration patterns of transgenes in cotton genome. We use conventional PCR and genomic Southern blot hybridization to characterize integration of T-DNA components and vector backbone fragments. For multiple-copy insertions into the same site (complex loci), transgene/transgene junctions (including canonical and truncated T-DNA and transgene involved vector backbone sequences) are characterized by PCR and sequencing. Inverse PCR and sequencing are used to characterize transgene/cotton genome junctions. Distribution of T-DNA insertion in cotton genome is evaluated by analysis of transgene flanking sequences. The pre-insertion sites can also be cloned and sequenced (based on the flanking sequences) for survey of genomic structure changes brought by transgene integration by comparing a pre-insertion site with corresponding transgene/plant junctions.

Combination of LiCs and EDLCs with Batteries: A New Paradigm of Hybrid Energy Storage for Application in EVs

The research presented in this paper proposes a hybrid energy storage system that combines both electrolytic double-layer capacitors (EDLCs) also known as supercapacitors (SCs) and lithium-ion capacitors (LiCs) also known as hybrid capacitors (HCs) with a battery through a multiple input converter. The proposal was verified in simulation and validated by implementing a laboratory prototype. A new hybridisation topology, which reduces the amount of resource requirement when compared to the conventional hybridisation topology, is introduced. An electric vehicle (EV) current profile from previous research was used to test the performance of the proposed topology. From the results obtained, the hybridisation topology proposed in this research had the lowest cost per unit power at 14.81 $/kW, the lowest cost per unit power to energy, and available power to energy ratio, both at 1:1.3, thus making it a more attractive hybridisation topology than the two conventional alternatives. The multiple input converter built had efficiency values in excess of 80%. The key take away from this paper is that using the proposed hybridisation topology, the battery is less often required to supply energy to the electric vehicle, and so, its cycle life is preserved. Furthermore, since the battery is not used for the repeated acceleration and deceleration in the entire driving cycle, the battery’s cycle life is further preserved. Furthermore, since the battery is not the only storage device in the energy storage system, it can be further downsized to best fit the required base load; therefore, leading to a more optimized energy storage system by reducing the weight and volume of space occupied by the energy storage system, while also achieving better efficiencies.

Reinforcement of resistance of modern rose to black spot disease via hybridization with Rosa rugosa

Most of the modern rose cultivars are susceptible to the highly destructive rose black spot disease caused by Marssonina rosae. In order to clarify the effect of hybridization with diploid Rosa rugosa on the morphological performance and black spot disease resistance of modern roses, we created the hybrid R. hybrida ‘Porcelina’ × R. rugosa ‘Dahong Zizhi’ and analyzed the morphological diversity and genetic constitution of 142 progeny. The progeny showed a wide range of variation, with a coefficient of variation of all traits of 40% and a maximum internode length of 118.9%. Cluster analysis of morphological traits and principal coordinate analysis of simple sequence repeats indicated that most of the progeny clustered with the female parent, while only a few individuals grouped with the male parent. Detached leaf assays were used to evaluate the black spot disease resistance of 75 lines and the two parents. The mean leaf area with symptoms (LAS) of the tested leaves of ‘Porcelina’ was 72.0 ± 12.9%, classifying it as highly susceptible, while R. rugosa showed high resistance to black spot disease. The coefficient of variation in LAS of the progeny was 68.1%, which indicates that the broad-spectrum resistance of rose black spot disease is controlled by multiple genes. A total of 11 progeny had an LAS < 10% and were significantly more resistant than the female parent. The results showed that the introduction of diploid R. rugosa into modern rose through conventional hybridization is effective at reinforcing resistance to black spot disease.

Creation of Large Hybrid Populations Using Male-sterile Germplasm as the Female Parent in Jujube

The establishment of large hybrid populations is the key basis to breeding new cultivars and genetic research, such as molecular mapping. However, it is extremely difficult to generate hybrid progeny using conventional artificial hybridization in Chinese jujube (Chinese date) (Ziziphus jujuba Mill.) because of its low fruit set of ≈0.01%. The objective of this study was to create large hybrid populations in Chinese jujube using bona fide male-sterile germplasm as the female parent. Two male-sterile varieties that lacked viable pollen (JMS1 and JMS2) previously discovered by our research group and three male-fertile genotypes (‘Xing16’, ‘Jiao5’, and ‘Wuhefeng’) were used as female and male parents, respectively. Bee-aided controlled hybridization of five combinations was conducted from 2014 to 2016. The results indicated that both JMS1 and JMS2 were stable male-sterile germplasm across the years examined. JMS2 showed more effective compatibility with the male parents tested than JMS1. A total of 7681 fruits were obtained from the five cross combinations, and 3120 of them contained seeds. The mean rate of the fruit with seed varied from 32.62% to 64.21%, and the highest rate (73.38%) was obtained from the cross of JMS2 × ‘Xing16’ in 2016. A total of 831 seedlings were obtained and consisted of 602 from JMS2 × ‘Xing16’, 221 from JMS2 × ‘Jiao5’, two from JMS1 × ‘Xing16’, five from JMS1 × ‘Wuhefeng’, and one from JMS2 × ‘Wuhefeng’. The 118 randomly selected progeny seedlings, including 96 from JMS2 × ‘Xing16’ and 22 from JMS2 × ‘Jiao5’, respectively, were identified to be authentic hybrids using SSR markers. Thus, JMS2 is a promising male-sterile female parent that possesses a good cross-compatibility and is free from the need for emasculation, embryo rescue, and hybrid identification. The largest hybrid population of 602 progeny was obtained in Chinese jujube using controlled hybridization. This study demonstrated the feasibility of a highly efficient crossbreeding approach using male-sterile germplasm as the female parent in Chinese jujube.

Selection and Clonal Propagation of High Artemisinin Genotypes of Artemisia annua.

Artemisinin, produced in the glandular trichomes of Artemisia annua L. is a vital antimalarial drug effective against Plasmodium falciparum resistant to quinine-derived medicines. Although work has progressed on the semi-synthetic production of artemisinin, field production of A. annua remains the principal commercial source of the compound. Crop production of artemisia must be increased to meet the growing worldwide demand for artemisinin combination therapies (ACTs) to treat malaria. Grower artemisinin yields rely on plants generated from seeds from open-pollinated parents. Although selection has considerably increased plant artemisinin concentration in the past 15 years, seed-generated plants have highly variable artemisinin content that lowers artemisinin yield per hectare. Breeding efforts to produce improved F1 hybrids have been hampered by the inability to produce inbred lines due to self-incompatibility. An approach combining conventional hybridization and selection with clonal propagation of superior genotypes is proposed as a means to enhance crop yield and artemisinin production. Typical seed-propagated artemisia plants produce less than 1% (dry weight) artemisinin with yields below 25 kg/ha. Genotypes were identified producing high artemisinin levels of over 2% and possessing improved agronomic characteristics such as high leaf area and shoot biomass production. Field studies of clonally-propagated high-artemisinin plants verified enhanced plant uniformity and an estimated gross primary productivity of up to 70 kg/ha artemisinin, with a crop density of one plant m-2. Tissue culture and cutting protocols for the mass clonal propagation of A. annua were developed for shoot regeneration, rooting, acclimatization, and field cultivation. Proof of concept studies showed that both tissue culture-regenerated plants and rooted cutting performed better than plants derived from seed in terms of uniformity, yield, and consistently high artemisinin content. Use of this technology to produce plants with homogeneously-high artemisinin can help farmers markedly increase the artemisinin yield per cultivated area. This would lead to increased profit to farmers and decreased prices of ACT.