Showing papers by "Rural Development Administration published in 2014"

Genome sequence of the hot pepper provides insights into the evolution of pungency in Capsicum species

Abstract: Doil Choi and colleagues report the genome sequence of the hot pepper, Capsicum annuum, as well as the resequencing of two cultivated peppers and a wild species, Capsicum chinense. Comparative genomic analysis across Solanaceae provides insights into genome expansion, pungency, ripening and disease resistance in hot peppers.

Genome sequence of mungbean and insights into evolution within Vigna species

Abstract: Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. Here we construct a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis, which includes several important dietary legumes in Asia, and to enable a better understanding of the evolution of leguminous species. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (V. reflexo-pilosa var. glabra) provides genomic evidence of a recent allopolyploid event. The species tree is constructed using de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.

An overview of calf diarrhea - infectious etiology, diagnosis, and intervention

Abstract: Calf diarrhea is a commonly reported disease in young animals, and still a major cause of productivity and economic loss to cattle producers worldwide. In the report of the 2007 National Animal Health Monitoring System for U.S. dairy, half of the deaths among unweaned calves was attributed to diarrhea. Multiple pathogens are known or postulated to cause or contribute to calf diarrhea development. Other factors including both the environment and management practices influence disease severity or outcomes. The multifactorial nature of calf diarrhea makes this disease hard to control effectively in modern cow-calf operations. The purpose of this review is to provide a better understanding of a) the ecology and pathogenesis of well-known and potential bovine enteric pathogens implicated in calf diarrhea, b) describe diagnostic tests used to detect various enteric pathogens along with their pros and cons, and c) propose improved intervention strategies for treating calf diarrhea.

Finding needles in haystacks: Linking scientific names, reference specimens and molecular data for Fungi

Abstract: DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi.

GlobalSoilMap: Toward a Fine-Resolution Global Grid of Soil Properties

Abstract: Soil scientists are being challenged to provide assessments of soil condition from local through to global scales. A particular issue is the need for estimates of the stores and fluxes in soils of water, carbon, nutrients, and solutes. This review outlines progress in the development and testing of GlobalSoilMap —a digital soil map that aims to provide a fine-resolution global grid of soil functional properties with estimates of their associated uncertainties. A range of methods can be used to generate the fine-resolution spatial estimates depending on the availability of existing soil surveys, environmental data, and point observations. The system has an explicit geometry for estimating point and block estimates of soil properties continuously down the soil profile. This geometry is necessary to ensure mass balance when stores and fluxes are computed. It also overcomes some limitations with existing systems for characterizing soil variation with depth. GlobalSoilMap has been designed to enable delivery of soil data via Web services. This review provides an overview of the system's technical specifications including the minimum data set. Examples from contrasting countries and environments are then presented to demonstrate the robustness of the technical specifications. GlobalSoilMap provides the means for supplying soil information in a format and resolution compatible with other fundamental data sets from remote sensing, terrain analysis, and other systems for mapping, monitoring, and forecasting biophysical processes. The initial research phase of the core project is nearing completion and attention is now shifting toward establishing the institutional and governance arrangements necessary to complete a full global coverage and maintaining the operational version of the GlobalSoilMap . This will be a grand and rewarding challenge for the soil science profession in the coming years.

Functional Roles of p38 Mitogen-Activated Protein Kinase in Macrophage-Mediated Inflammatory Responses

Abstract: Inflammation is a natural host defensive process that is largely regulated by macrophages during the innate immune response. Mitogen-activated protein kinases (MAPKs) are proline-directed serine and threonine protein kinases that regulate many physiological and pathophysiological cell responses. p38 MAPKs are key MAPKs involved in the production of inflammatory mediators, including tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2). p38 MAPK signaling plays an essential role in regulating cellular processes, especially inflammation. In this paper, we summarize the characteristics of p38 signaling in macrophage-mediated inflammation. In addition, we discuss the potential of using inhibitors targeting p38 expression in macrophages to treat inflammatory diseases.

The Draft Genome Sequence of European Pear (Pyrus communis L. ‘Bartlett’)

Abstract: We present a draft assembly of the genome of European pear (Pyrus communis) ‘Bartlett’. Our assembly was developed employing second generation sequencing technology (Roche 454), from single-end, 2 kb, and 7 kb insert paired-end reads using Newbler (version 2.7). It contains 142,083 scaffolds greater than 499 bases (maximum scaffold length of 1.2 Mb) and covers a total of 577.3 Mb, representing most of the expected 600 Mb Pyrus genome. A total of 829,823 putative single nucleotide polymorphisms (SNPs) were detected using re-sequencing of ‘Louise Bonne de Jersey’ and ‘Old Home’. A total of 2,279 genetically mapped SNP markers anchor 171 Mb of the assembled genome. Ab initio gene prediction combined with prediction based on homology searching detected 43,419 putative gene models. Of these, 1219 proteins (556 clusters) are unique to European pear compared to 12 other sequenced plant genomes. Analysis of the expansin gene family provided an example of the quality of the gene prediction and an insight into the relationships among one class of cell wall related genes that control fruit softening in both European pear and apple (Malus×domestica). The ‘Bartlett’ genome assembly v1.0 (http://www.rosaceae.org/species/pyrus/pyrus_communis/genome_v1.0) is an invaluable tool for identifying the genetic control of key horticultural traits in pear and will enable the wide application of marker-assisted and genomic selection that will enhance the speed and efficiency of pear cultivar development.

Rapid green synthesis of silver nanoparticles from Chrysanthemum indicum L and its antibacterial and cytotoxic effects: an in vitro study.

Abstract: The present work reports a simple, cost-effective, and ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using Chrysanthemum indicum and its antibacterial and cytotoxic effects. The formation of AgNPs was confirmed by color change, and it was further characterized by ultraviolet-visible spectroscopy (435 nm). The phytochemical screening of C. indicum revealed the presence of flavonoids, terpenoids, and glycosides, suggesting that these compounds act as reducing and stabilizing agents. The crystalline nature of the synthesized particles was confirmed by X-ray diffraction, as they exhibited face-centered cubic symmetry. The size and morphology of the particles were characterized by transmission electron microscopy, which showed spherical shapes and sizes that ranged between 37.71-71.99 nm. Energy-dispersive X-ray spectroscopy documented the presence of silver. The antimicrobial effect of the synthesized AgNPs revealed a significant effect against the bacteria Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Additionally, cytotoxic assays showed no toxicity of AgNPs toward 3T3 mouse embryo fibroblast cells (25 μg/mL); hence, these particles were safe to use.

Phylogenetic-based nomenclatural proposals for Ophiocordycipitaceae (Hypocreales) with new combinations in Tolypocladium.

Abstract: Ophiocordycipitaceae is a diverse family comprising ecologically, economically, medicinally, and culturally important fungi. The family was recognized due to the polyphyly of the genus Cordyceps and the broad diversity of the mostly arthropod-pathogenic lineages of Hypocreales. The other two cordyceps-like families, Cordycipitaceae and Clavicipitaceae, will be revised taxonomically elsewhere. Historically, many species were placed in Cordyceps, but other genera have been described in this family as well, including several based on anamorphic features. Currently there are 24 generic names in use across both asexual and sexual life stages for species of Ophiocordycipitaceae. To reflect changes in Art. 59 in the International Code of Nomenclature for algae, fungi, and plants (ICN), we propose to protect and to suppress names within Ophiocordycipitaceae, and to present taxonomic revisions in the genus Tolypocladium, based on rigorous and extensively sampled molecular phylogenetic analyses. When approaching this task, we considered the principles of priority, monophyly, minimizing taxonomic revisions, and the practical utility of these fungi within the wider biological research community.

ABD1 Is an Arabidopsis DCAF Substrate Receptor for CUL4-DDB1-based E3 Ligases That Acts as a Negative Regulator of Abscisic Acid Signaling

Abstract: Members of the DDB1-CUL4–associated factors (DCAFs) family directly bind to DAMAGED DNA BINDING PROTEIN1 (DDB1) and function as the substrate receptors in CULLIN4-based E3 (CUL4) ubiquitin ligases, which regulate the selective ubiquitination of proteins. Here, we describe a DCAF protein, ABD1 (for ABA-hypersensitive DCAF1), that negatively regulates abscisic acid (ABA) signaling in Arabidopsis thaliana. ABD1 interacts with DDB1 in vitro and in vivo, indicating that it likely functions as a CUL4 E3 ligase substrate receptor. ABD1 expression is induced by ABA, and mutations in ABD1 result in ABA- and NaCl-hypersensitive phenotypes. Loss of ABD1 leads to hyperinduction of ABA-responsive genes and higher accumulation of the ABA-responsive transcription factor ABA INSENSITIVE5 (ABI5), hypersensitivity to ABA during seed germination and seedling growth, enhanced stomatal closure, reduced water loss, and, ultimately, increased drought tolerance. ABD1 directly interacts with ABI5 in yeast two-hybrid assays and associates with ABI5 in vivo by coimmunoprecipitation, and the interaction was found in the nucleus by bimolecular fluorescence complementation. Furthermore, loss of ABD1 results in a retardation of ABI5 degradation by the 26S proteasome. Taken together, these data suggest that the DCAF-CUL4 E3 ubiquitin ligase assembled with ABD1 is a negative regulator of ABA responses by directly binding to and affecting the stability of ABI5 in the nucleus.

Functional roles of Syk in macrophage-mediated inflammatory responses

Abstract: Inflammation is a series of complex biological responses to protect the host from pathogen invasion. Chronic inflammation is considered a major cause of diseases, such as various types of inflammatory/autoimmune diseases and cancers. Spleen tyrosine kinase (Syk) was initially found to be highly expressed in hematopoietic cells and has been known to play crucial roles in adaptive immune responses. However, recent studies have reported that Syk is also involved in other biological functions, especially in innate immune responses. Although Syk has been extensively studied in adaptive immune responses, numerous studies have recently presented evidence that Syk has critical functions in macrophage-mediated inflammatory responses and is closely related to innate immune response. This review describes the characteristics of Syk-mediated signaling pathways, summarizes the recent findings supporting the crucial roles of Syk in macrophage-mediated inflammatory responses and diseases, and discusses Syk-targeted drug development for the therapy of inflammatory diseases.

Whole genome and global gene expression analyses of the model mushroom Flammulina velutipes reveal a high capacity for lignocellulose degradation.

Abstract: Flammulina velutipes is a fungus with health and medicinal benefits that has been used for consumption and cultivation in East Asia. F. velutipes is also known to degrade lignocellulose and produce ethanol. The overlapping interests of mushroom production and wood bioconversion make F. velutipes an attractive new model for fungal wood related studies. Here, we present the complete sequence of the F. velutipes genome. This is the first sequenced genome for a commercially produced edible mushroom that also degrades wood. The 35.6-Mb genome contained 12,218 predicted protein-encoding genes and 287 tRNA genes assembled into 11 scaffolds corresponding with the 11 chromosomes of strain KACC42780. The 88.4-kb mitochondrial genome contained 35 genes. Well-developed wood degrading machinery with strong potential for lignin degradation (69 auxiliary activities, formerly FOLymes) and carbohydrate degradation (392 CAZymes), along with 58 alcohol dehydrogenase genes were highly expressed in the mycelium, demonstrating the potential application of this organism to bioethanol production. Thus, the newly uncovered wood degrading capacity and sequential nature of this process in F. velutipes, offer interesting possibilities for more detailed studies on either lignin or (hemi-) cellulose degradation in complex wood substrates. The mutual interest in wood degradation by the mushroom industry and (ligno-)cellulose biomass related industries further increase the significance of F. velutipes as a new model.

The CCAAT box-binding transcription factor NF-YA1 controls rhizobial infection

Abstract: Symbiosis between legume plants and soil rhizobia culminates in the formation of a novel root organ, the ‘nodule’, containing bacteria differentiated as facultative nitrogen-fixing organelles. MtNF-YA1 is a Medicago truncatula CCAAT box-binding transcription factor (TF), formerly called HAP2-1, highly expressed in mature nodules and required for nodule meristem function and persistence. Here a role for MtNF-YA1 during early nodule development is demonstrated. Detailed expression analysis based on RNA sequencing, quantitiative real-time PCR (qRT-PCR), as well as promoter–β-glucuronidase (GUS) fusions reveal that MtNF-YA1 is first induced at the onset of symbiotic development during preparation for, and initiation and progression of, symbiotic infection. Moreover, using a new knock-out mutant, Mtnf-ya1-1, it is shown that MtNF-YA1 controls infection thread (IT) progression from initial root infection through colonization of nodule tissues. Extensive confocal and electronic microscopic observations suggest that the bulbous and erratic IT growth phenotypes observed in Mtnf-ya1-1 could be a consequence of the fact that walls of ITs in this mutant are thinner and less coherent than in the wild type. It is proposed that MtNF-YA1 controls rhizobial infection progression by regulating the formation and the wall of ITs.

Population Structure and Domestication Revealed by High-Depth Resequencing of Korean Cultivated and Wild Soybean Genomes

Abstract: Despite the importance of soybean as a major crop, genome-wide variation and evolution of cultivated soybeans are largely unknown. Here, we catalogued genome variation in an annual soybean population by high-depth resequencing of 10 cultivated and 6 wild accessions and obtained 3.87 million high-quality single-nucleotide polymorphisms (SNPs) after excluding the sites with missing data in any accession. Nuclear genome phylogeny supported a single origin for the cultivated soybeans. We identified 10-fold longer linkage disequilibrium (LD) in the wild soybean relative to wild maize and rice. Despite the small population size, the long LD and large SNP data allowed us to identify 206 candidate domestication regions with significantly lower diversity in the cultivated, but not in the wild, soybeans. Some of the genes in these candidate regions were associated with soybean homologues of canonical domestication genes. However, several examples, which are likely specific to soybean or eudicot crop plants, were also observed. Consequently, the variation data identified in this study should be valuable for breeding and for identifying agronomically important genes in soybeans. However, the long LD of wild soybeans may hinder pinpointing causal gene(s) in the candidate regions.

Detection of Starch Adulteration in Onion Powder by FT-NIR and FT-IR Spectroscopy

Abstract: Adulteration of onion powder with cornstarch was identified by Fourier transform near-infrared (FT-NIR) and Fourier transform infrared (FT-IR) spectroscopy. The reflectance spectra of 180 pure and adulterated samples (1-35 wt % starch) were collected and preprocessed to generate calibration and prediction sets. A multivariate calibration model of partial least-squares regression (PLSR) was executed on the pretreated spectra to predict the presence of starch. The PLSR model predicted adulteration with an R(p)2 of 0.98 and a standard error of prediction (SEP) of 1.18% for the FT-NIR data and an R(p)2 of 0.90 and SEP of 3.12% for the FT-IR data. Thus, the FT-NIR data were of greater predictive value than the FT-IR data. Principal component analysis on the preprocessed data identified the onion powder in terms of added starch. The first three principal component loadings and β coefficients of the PLSR model revealed starch-related absorption. These methods can be applied to rapidly detect adulteration in other spices.

Comparison of biomass production and total lipid content of freshwater green microalgae cultivated under various culture conditions

Abstract: The growth and total lipid content of four green microalgae (Chlorella sp., Chlorella vulgaris CCAP211/11B, Botryococcus braunii FC124 and Scenedesmus obliquus R8) were investigated under different culture conditions. Among the various carbon sources tested, glucose produced the largest biomass or microalgae grown heterotrophically. It was found that 1 % (w/v) glucose was actively utilized by Chlorella sp., C. vulgaris CCAP211/11B and B. braunii FC124, whereas S. obliquus R8 preferred 2 % (w/v) glucose. No significant difference in biomass production was noted between heterotrophic and mixotrophic (heterotrophic with light illumination/exposure) growth conditions, however, less production was observed for autotrophic cultivation. Total lipid content in cells increased by approximately two-fold under mixotrophic cultivation with respect to heterotrophic and autotrophic cultivation. In addition, light intensity had an impact on microalgal growth and total lipid content. The highest total lipid content was observed at 100 μmol m−2s−1 for Chlorella sp. (22.5 %) and S. obliquus R8 (23.7 %) and 80 μmol m−2s−1 for C. vulgaris CCAP211/11B (20.1 %) and B. braunii FC124 (34.9 %).

Variation of glucosinolates in 62 varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) and their antioxidant activity

Abstract: Glucosinolate (GSL) and antioxidant activity in 62 varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) were determined by HPLC and DPPH, HRSA, and FRAP assays. Five aliphatic GSLs: progoitrin, sinigrin, glucoalyssin, gluconapin, and glucobrassicanapin; four indolyl GSLs: 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin; one aromatic GSL: gluconasturtiin were identified. Glucobrassicanapin and gluconapin documented the most abundant (average 4.52 and 3.72 μmol/g DW, respectively). The contents of total GSLs varied extensively among 62 varieties (range from 2.83 to 48.53 μmol/g DW). Comprehensive differences in total and individual GSL contents have also been observed among different varieties. Indolyl and aromatic GSL together accounted 26% of the total GSLs; but there are few differences among varieties. FC7 and FI17 could be good candidates for future breeding programs since they had a high quantity of glucobrassicin (2.10 and 1.66 μmol/g DW, respectively). Most of the Chinese cabbage varieties showed significant antioxidant activities when compare with positive control. However, three antioxidant assays were not significantly correlated with total GSLs. The presence of significant quantities of glucobrassicin in some varieties should be studied more extensively, since GSL is the precursor of indole-3-carbinol, a potent anticancer isothiocyanate.

Inhibitory effects of resveratrol on melanin synthesis in ultraviolet B-induced pigmentation in Guinea pig skin.

Abstract: Resveratrol is a polyphenolic compound found in various natural products such as grapes and berries and possesses anti-cancer, anti-hyperlipidemia, and anti-aging properties. Recently, it has been reported that resveratrol inhibits α-melanocyte-stimulating hormone signaling, viability, and migration in melanoma cells. However, these effects have not been confirmed in vivo, specifically brownish guinea pigs. To evaluate the potential of resveratrol as a regulator of melanin for hyperpigmentation therapy, the influence of resveratrol on pigmentation was investigated by ultraviolet B-induced hyperpigmentation in brownish guinea pig skin. We found that resveratrol reduced the expression of melanogenesis-related proteins tyrosinase, tyrosinase-related proteins 1 and 2, and microphthalmia-associated transcription factor in melanoma cells. Furthermore, topical application of resveratrol was demonstrated to significantly decrease hyperpigmentation on ultraviolet B-stimulated guinea pig skin in vivo. Based on our histological data, resveratrol inhibits melanin synthesis via a reduction in tyrosinase-related protein 2 among the melanogenic enzymes. This study is the first to provide evidence supporting resveratrol as a depigmentation agent, along with further clinical investigation of resveratrol in ultraviolet B-induced skin disorders such as hyperpigmentation and skin photoaging.

Screening and Characterization of a Novel Cellulase Gene from the Gut Microflora of Hermetia illucens Using Metagenomic Library

Abstract: A metagenomic fosmid library was constructed using genomic DNA isolated from the gut microflora of Hermetia illucens, a black soldier fly. A cellulase-positive clone, with the CS10 gene, was identified by extensive Congo-red overlay screenings for cellulase activity from the fosmid library of 92,000 clones. The CS10 gene was composed of a 996 bp DNA sequence encoding the mature protein of 331 amino acids. The deduced amino acids of CS10 showed 72% sequence identity with the glycosyl hydrolase family 5 gene of Dysgonomonas mossii, displaying no significant sequence homology to already known cellulases. The purified CS10 protein presented a single band of cellulase activity with a molecular mass of approximately 40 kDa on the SDS-PAGE gel and zymogram. The purified CS10 protein exhibited optimal activity at 50°C and pH 7.0, and the thermostability and pH stability of CS10 were preserved at the ranges of 20~50°C and pH 4.0~10.0. CS10 exhibited little loss of cellulase activity against various chemical reagents such as 10% polar organic solvents, 1% non-ionic detergents, and 0.5 M denaturing agents. Moreover, the substrate specificity and the product patterns by thinlayer chromatography suggested that CS10 is an endo-β-1,4-glucanase. From these biochemical properties of CS10, it is expected that the enzyme has the potential for application in industrial processes.

Major Repeat Components Covering One-Third of the Ginseng (Panax Ginseng C.A. Meyer) Genome and Evidence for Allotetraploidy

Abstract: Summary Ginseng (Panax ginseng) is a famous medicinal herb, but the composition and structure of its genome are largely unknown. Here we characterized the major repeat components and inspected their distribution in the ginseng genome. By analyzing three repeat-rich bacterial artificial chromosome (BAC) sequences from ginseng, we identified complex insertion patterns of 34 long terminal repeat retrotransposons (LTR-RTs) and 11 LTR-RT derivatives accounting for more than 80% of the BAC sequences. The LTR-RTs were classified into three Ty3/gypsy (PgDel, PgTat and PgAthila) and two Ty1/Copia (PgTork and PgOryco) families. Mapping of 30-Gbp Illumina whole-genome shotgun reads to the BAC sequences revealed that these five LTR-RT families occupy at least 34% of the ginseng genome. The Ty3/Gypsy families were predominant, comprising 74 and 33% of the BAC sequences and the genome, respectively. In particular, the PgDel family accounted for 29% of the genome and presumably played major roles in enlargement of the size of the ginseng genome. Fluorescence in situ hybridization (FISH) revealed that the PgDel1 elements are distributed throughout the chromosomes along dispersed heterochromatic regions except for ribosomal DNA blocks. The intensity of the PgDel2 FISH signals was biased toward 24 out of 48 chromosomes. Unique gene probes showed two pairs of signals with different locations, one pair in subtelomeric regions on PgDel2-rich chromosomes and the other in interstitial regions on PgDel2-poor chromosomes, demonstrating allotetraploidy in ginseng. Our findings promote understanding of the evolution of the ginseng genome and of that of related species in the Araliaceae.

Recent Progress in Cryopreservation of Bovine Oocytes

Abstract: Principle of oocyte cryoinjury is first overviewed and then research history of cryopreservation using bovine oocytes is summarized for the last two decades with a few special references to recent progresses. Various types of cryodevices have been developed to accelerate the cooling rate and applied to the oocytes from large domestic species enriched with cytoplasmic lipid droplets. Two recent approaches include the qualitative improvement of IVM oocytes prior to the vitrification and the short-term recovery culture of vitrified-warmed oocytes prior to the subsequent IVF. Supplementation of L-carnitine to IVM medium of bovine oocytes has been reported to reduce the amount of cytoplasmic lipid droplets and improve the cryotolerance of the oocytes, but it is still controversial whether the positive effect of L-carnitine is reproducible. Incidence of multiple aster formation, a possible cause for low developmental potential of vitrified-warmed bovine oocytes, was inhibited by a short-term culture of the postwarm oocytes in the presence of Rho-associated coiled-coil kinase (ROCK) inhibitor. Use of an antioxidant α-tocopherol, instead of the ROCK inhibitor, also supported the revivability of the postwarm bovine oocytes. Further improvements of the vitrification procedure, combined with pre- and postvitrification chemical treatment, would overcome the high sensitivity of bovine oocytes to cryopreservation.

QTL mapping and development of candidate gene-derived DNA markers associated with seedling cold tolerance in rice (Oryza sativa L.)

Abstract: Cold stress at the seedling stage is a major threat to rice production. Cold tolerance is controlled by complex genetic factors. We used an F7 recombinant inbred line (RIL) population of 123 individuals derived from a cross of the cold-tolerant japonica cultivar Jinbu and the cold-susceptible indica cultivar BR29 for QTL mapping. Phenotypic evaluation of the parents and RILs in an 18/8 °C (day/night) cold stress regime revealed continuous variation for cold tolerance. Six QTLs including two on chromosome 1 and one each on chromosomes 2, 4, 10, and 11 for seedling cold tolerance were identified with phenotypic variation (R 2) ranging from 6.1 to 16.5 %. The QTL combinations (qSCT1 and qSCT11) were detected in all stable cold-tolerant RIL groups, which explained the critical threshold of 27.1 % for the R 2 value determining cold tolerance at the seedling stage. Two QTLs (qSCT1 and qSCT11) on chromosomes 1 and 11, respectively, were fine mapped. The markers In1-c3, derived from the open reading frame (ORF) LOC_Os01g69910 encoding calmodulin-binding transcription activator (CAMTA), and In11-d1, derived from ORF LOC_Os11g37720 (Duf6 gene), co-segregated with seedling cold tolerance. The result may provide useful information on seedling cold tolerance mechanism and provide DNA markers for a marker-assisted breeding program to improve seedling cold tolerance in indica rice varieties.

Insecticide resistance monitoring and correlation analysis to select appropriate insecticides against Nilaparvata lugens (Stål), a migratory pest in Korea

Abstract: Nilaparvata lugens Stal is one of the important migratory pests of rice paddy fields in Korea. Resistance levels to nine insecticides were monitored in 12 local strains and correlation analysis was conducted to determine cross-resistance relationships among the tested insecticides. The local strains revealed 1.3- to 28.0-, 1.6- to 6.0-, 2.8- to 237.0-, 0.6- to 0.9-, and 0.7- to 1.3-fold resistance to carbamates, organophosphates, neonicotinoids, fipronil and etofenprox, respectively. Organophosphate insecticides revealed moderate correlations with benzofuranyl methylcarbamate (r = 0.566–0.614, p > 0.01). Three neonicotinoids were not correlated with each other, but imidacloprid and clothianidin were moderately correlated with several benzofuranyl methylcarbamate and organophosphate insecticides (r = 0.590–0.705, p > 0.05), indicating that unknown common factors (such as detoxification enzymes) might contribute to resistance to both insecticides. Fipronil and etofenprox exhibited low levels of resistance and cross-resistance with other insecticides, suggesting their potential as an effective insecticide for field application. Resistance level monitoring and correlation analysis would be valuable for the selection of appropriate insecticides to control insecticide-resistant N. lugens, a typical migratory pest in Korea.