The Genetic Basis for Constructing Selection Indexes

Genomic selection for spot blotch in bread wheat breeding panels, full-sibs and half-sibs and index-based selection for spot blotch, heading and plant height

KEY MESSAGE

Genomic selection is a promising tool to select for spot blotch resistance and index-based selection can simultaneously select for spot blotch resistance, heading and plant height. A major biotic stress challenging bread wheat production in regions characterized by humid and warm weather is spot blotch caused by the fungus Bipolaris sorokiniana. Since genomic selection (GS) is a promising selection tool, we evaluated its potential for spot blotch in seven breeding panels comprising 6736 advanced lines from the International Maize and Wheat Improvement Center. Our results indicated moderately high mean genomic prediction accuracies of 0.53 and 0.40 within and across breeding panels, respectively which were on average 177.6% and 60.4% higher than the mean accuracies from fixed effects models using selected spot blotch loci. Genomic prediction was also evaluated in full-sibs and half-sibs panels and sibs were predicted with the highest mean accuracy (0.63) from a composite training population with random full-sibs and half-sibs. The mean accuracies when full-sibs were predicted from other full-sibs within families and when full-sibs panels were predicted from other half-sibs panels were 0.47 and 0.44, respectively. Comparison of GS with phenotypic selection (PS) of the top 10% of resistant lines suggested that GS could be an ideal tool to discard susceptible lines, as greater than 90% of the susceptible lines discarded by PS were also discarded by GS. We have also reported the evaluation of selection indices to simultaneously select non-late and non-tall genotypes with low spot blotch phenotypic values and genomic-estimated breeding values. Overall, this study demonstrates the potential of integrating GS and index-based selection for improving spot blotch resistance in bread wheat.

Silver Nanoparticles Formation by Jatropha integerrima and LC/MS-QTOF-Based Metabolite Profiling

The broad application of metal nanoparticles in different fields encourages scientists to find alternatives to conventional synthesis methods to reduce negative environmental impacts. Herein, we described a safe method for preparing silver nanoparticles (J-AgNPs) using Jatropha integerrima leaves extract as a reducing agent and further characterize its physiochemical and pharmacological properties to identify its therapeutic potential as a cytotoxic and antimicrobial agent. The biogenic synthesized J-AgNPs were physiochemically characterized by ultraviolet-visible spectroscopy, dynamic light scattering (DLS), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy. HPLC-DAD, followed by LC/MS and the Fourier-transform infrared spectroscopy (FTIR), was applied to detect the biomolecules of J. integerrima involved in the fabrication of NPs. Furthermore, J-AgNPs and the ampicillin-nanocomposite conjugate were investigated for their potential antibacterial effects against four clinical isolates. Finally, cytotoxic effects were also investigated against cancer and normal cell lines, and their mechanism was assessed using TEM analysis and confocal laser scanning microscopy (LSM). Ag ions were reduced to spherical J-AgNPs, with a zeta potential of −34.7 mV as well as an average size of 91.2 and 22.8 nm as detected by DLS and TEM, respectively. HPLC GC/MC analysis identified five biomolecules, and FTIR suggested the presence of proteins besides polyphenolic molecules; together, these molecules could be responsible for the reduction and capping processes during NP formation. Additionally, J-AgNPs displayed a strong antibacterial effect, although the ampicillin conjugated form had a very weak antibacterial effect. Furthermore, the NPs caused a reduction in cell viability of all the treated cells by initiating ultrastructural changes and apoptosis, as identified by TEM and LSM analysis. Therefore, J-AgNPs can be formed using the leaf extract from the J. integerrima plant. Furthermore, J-AgNPs may serve as a candidate for further biochemical and pharmacological testing to identify its therapeutic value.

Increasing selection gain and accuracy of harvest prediction models in Jatropha through genome-wide selection

Genome-wide selection (GWS) has been becoming an essential tool in the genetic breeding of long-life species, as it increases the gain per time unit. This study had a hypothesis that GWS is a tool that can decrease the breeding cycle in Jatropha. Our objective was to compare GWS with phenotypic selection in terms of accuracy and efficiency over three harvests. Models were developed throughout the harvests to evaluate their applicability in predicting genetic values in later harvests. For this purpose, 386 individuals of the breeding population obtained from crossings between 42 parents were evaluated. The population was evaluated in random block design, with six replicates over three harvests. The genetic effects of markers were predicted in the population using 811 SNP's markers with call rate = 95% and minor allele frequency (MAF) > 4%. GWS enables gains of 108 to 346% over the phenotypic selection, with a 50% reduction in the selection cycle. This technique has potential for the Jatropha breeding since it allows the accurate obtaining of GEBV and higher efficiency compared to the phenotypic selection by reducing the time necessary to complete the selection cycle. In order to apply GWS in the first harvests, a large number of individuals in the breeding population are needed. In the case of few individuals in the population, it is recommended to perform a larger number of harvests.

The genus Jatropha (Euphorbiaceae): A review on secondary chemical metabolites and biological aspects

The genus Jatropha belongs to the Euphorbiaceae family and has about 175 species. Originally from tropical America, the Jatropha genus can be found all over the tropics and subtropics of Asia and Africa. Jatropha species are recognized to be important sources of secondary metabolites with a broad spectrum of biological functions. Extracts and isolated compounds from species of this genus have been known to have properties of cytotoxicity, antimicrobial, antifungal, anti-inflammatory, antioxidant, insecticidal, larvicidal, inhibition AChE, and toxicity activities. Investigations on the chemical aspects of the genus Jatropha have led to the identification of cyclic peptides, lignans, flavonoids, coumarins, alkaloids, eudesmenoic acids, and mainly terpenes. In this review, we provide a comprehensive picture of the phytochemical and biological characteristics of Jatropha species. The information gathered and approached in this paper might support the planning and discussion of future studies on the topic.

JCDB: a comprehensive knowledge base for Jatropha curcas, an emerging model for woody energy plants

Background

Jatropha curcas is an oil-bearing plant, and has seeds with high oil content (~ 40%). Several advantages, such as easy genetic transformation and short generation duration, have led to the emergence of J. curcas as a model for woody energy plants. With the development of high-throughput sequencing, the genome of Jatropha curcas has been sequenced by different groups and a mass of transcriptome data was released. How to integrate and analyze these omics data is crucial for functional genomics research on J. curcas.

Results

By establishing pipelines for processing novel gene identification, gene function annotation, and gene network construction, we systematically integrated and analyzed a series of J. curcas transcriptome data. Based on these data, we constructed a J. curcas database (JCDB), which not only includes general gene information, gene functional annotation, gene interaction networks, and gene expression matrices but also provides tools for browsing, searching, and downloading data, as well as online BLAST, the JBrowse genome browser, ID conversion, heatmaps, and gene network analysis tools.

Conclusions

JCDB is the most comprehensive and well annotated knowledge base for J. curcas. We believe it will make a valuable contribution to the functional genomics study of J. curcas. The database is accessible at http://jcdb.xtbg.ac.cn.

The Sustainable Cultivation of Mexican Nontoxic Jatropha Curcas to Produce Biodiesel and Food in Marginal Rural Lands

The objective of this study is to identify Mexican nontoxic ecotypes of Jatropha curcas with potential for a sustainable agriculture practice to produce biodiesel and food products through a methodology and criteria of sustainability. In a rural region of Morelos state in central México, nine Mexican ecotypes of Jatropha curcas were evaluated in an experimental plantation with minimal water resources and fertilization. The experimental trial was assessed in terms of (1) toxicity, (2) growth and survival of the plants, (3) yield of seed, (4) residual biomass production, (5) oil characteristics for biodiesel production, (6) nutrimental properties of the seeds, and (7) changes in the chemical properties of the soil. Finally, two outstanding nontoxic ecotypes were identified as the most suitable for the establishment of Jatropha curcas crops to produce biodiesel and, at the same time, for food products using the de-oiled endosperm cake, for energy production from the residual biomass and for improvement of soil properties in marginal lands of rural regions of Morelos state.

Using Biofuels for Highly Renewable Electricity Systems: A Case Study of the Jatropha curcas

Recent movements for the decarbonization of the electricity sector have become a priority for many countries around the world and will inevitably lead to the sharp decline of fossil-fuel-based energy. Energy from fossil fuels is to be replaced by renewable energy sources (RES), although the transition will neither be cheap nor smooth. One sustainable and environmentally friendly alternative to fossil fuels and which will take a considerable share in the increasing supply of renewable energy resources is biofuels. There are various types of biofuels used in practice; however, biodiesels represent one of the most popular and widespread ones. This paper focuses as a case study on the byproducts of Jatropha curcas, a crop and a plant that is already used for biofuel production and which is subsequently employed in electricity generation in Jatropha curcas producing regions. This paper identifies the limitations and prospects of Jatropha curcas utilization. Also, Jatropha curcas is compared to other materials suitable for biomass generation. An economic analysis for a 2 MW biofuel powerplant was conducted incorporating various market-related risks. The study shows that at current prices, net profitability can be achieved using Jatropha curcas byproducts for producing electricity.