摘要:
No ascovirus isolated from China has been sequenced so far. Therefore, in this study, we aimed to sequence the genome of Heliothis virescens ascovirus 3h (HvAV-3h) using the 454 pyrosequencing technology. The genome was found to be 190,519-bp long with a G+C content of 45.5%. We also found that it encodes 185 hypothetical open reading frames (ORFs) along with at least 50 amino acids, including 181 ORFs found in other ascoviruses and 4 unique ORFs. Gene-parity plots and phylogenetic analysis revealed a close relationship between HvAV-3h and three other HvAV-3a strains and a distant relationship with Spodoptera frugiperda ascovirus 1a (SfAV-1a), Trichoplusia ni ascovirus 6a (TnAV-6a), and Diadromus pulchellus ascovirus 4a (DpAV-4a). Among the 185 potential genes encoded by the genome, 44 core genes were found in all the sequenced ascoviruses. In addition, 25 genes were found to be conserved in all ascoviruses except DpAV-4a. In the HvAV-3h genome, 24 baculovirus repeat ORFs (bros) were present, and the typical homologous repeat regions (hrs) were absent. This study supplies information important for understanding the conservation and functions of ascovirus genes as well as the variety of ascoviral genomes.
通讯机构:
[Xu, C.] Y;[Hu, Z.] W;Yangzhou Univ, Jiangsu Prov Key Lab Crop Genet & Physiol, Coinnovat Ctr Modern Prod Technol Grain Crops, Key Lab Plant Funct Genom,Minist Educ, Yangzhou 225009, Jiangsu, Peoples R China.;Wuhan Univ, Coll Life Sci, State Key Lab Hybrid Rice, Wuhan 430072, Peoples R China.
摘要:
Genomic selection (GS) is more efficient than traditional phenotype-based methods in hybrid breeding. The present study investigated the predictive ability of genomic best linear unbiased prediction models for rice hybrids based on the North Carolina mating design II, in which a total of 115 inbred rice lines were crossed with 5 male sterile lines. Using 8 traits of the 575 (115 × 5) hybrids from two environments, both univariate (UV) and multivariate (MV) prediction analyses, including additive and dominance effects, were performed. Using UV models, the prediction results of cross-validation indicated that including dominance effects could improve the predictive ability for some traits in rice hybrids. Additionally, we could take advantage of GS even for a low-heritability trait, such as grain yield per plant (GY), because a modest increase in the number of top selection could generate a higher, more stable mean phenotypic value for rice hybrids. Thus this strategy was used to select superior potential crosses between the 115 inbred lines and those between the 5 male sterile lines and other genotyped varieties. In our MV research, an MV model (MV-ADV) was developed utilizing a MV relationship matrix constructed with auxiliary variates. Based on joint analysis with multi-trait (MT) or with multi-environment, the prediction results confirmed the superiority of MV-ADV over an UV model, particularly in the MT scenario for a low-heritability target trait (such as GY), with highly correlated auxiliary traits. For a high-heritability trait (such as thousand-grain weight), MT prediction is unnecessary, and UV prediction is sufficient.
摘要:
Inward rectifier potassium (Kir) channels play fundamental roles in neuromuscular, epithelial, and endocrine function in mammals. Recent research in insects suggests that Kir channels play critical roles in the development, immune function, and excretory physiology of fruit flies and/or mosquitoes. Moreover, our group has demonstrated that mosquito Kir channels may serve as valuable targets for the development of novel insecticides. Here we characterize the molecular expression of 5 mRNAs encoding Kir channel subunits in the yellow fever mosquito, Aedes aegypti: Kin, Kir2A-c, Kir2B, Kir2B', and Kir3. We demonstrate that 1) Kir mRNA expression is dynamic in whole mosquitoes, Malpighian tubules, and the midgut during development from 4th instar larvae to adult females, 2) Kir2B and Kir3 mRNA levels are reduced in 4th instar larvae when reared in water containing an elevated concentration (50 mM) of KCI, but not NaCl, and 3) Kir mRNAs are differentially expressed in the Malpighian tubules, midgut, and ovaries within 24 h after blood feeding. Furthermore, we provide the first characterization of Kir mRNA expression in the anal papillae of 4th instar larval mosquitoes, which indicates that Kir2A-c is the most abundant. Altogether, the data provide the first comprehensive characterization of Kir mRNA expression in Ae. aegypti and offer insights into the putative physiological roles of Kir subunits in this important disease vector. (C) 2016 Elsevier Inc. All rights reserved.
摘要:
Fu brick tea is a unique post-fermented tea product which is fermented with microorganism during the manufacturing process. Metabolic analysis showed that most metabolites content were decreased during the manufacturing process of Fu brick tea, except GA (gallic acid). Illumina MiSeq sequencing of ITS gene amplicons was applied to analyze the fungal community succession. The genera Aspergillus, Cyberlindnera and Candida were predominant at the early stage of manufacturing process (from "primary dark tea" to "fermentation for 3 days"), but after the stage of "fermentation for 3 days" only Aspergillus was still dominated, and maintain a relatively constant until to the end of manufacturing process. The effects of metabolites on the structure of the fungal community were analyzed by redundancy analysis (RDA) and variation partitioning analysis (VPA). The results indicated that GCG (gallocatechin gallate), EGCG (epigallocatechin gallate) and GA as well as the interactions among them were the most probably ones to influence, or be influenced by the fungal communities during the fermentation process of Fu brick tea. This study revealed fungal succession, metabolite changes and their relationships, provided new insights into the mechanisms for manufacturing process of Fu brick tea.
摘要:
BACKGROUND: In recent years, two of the crinivirus, Tomato chlorosis virus (ToCV) and Cucurbit chlorotic yellows virus (CCYV) have gained increasing attention due to their rapid spread and devastating impacts on vegetable production worldwide. Both of these viruses are transmitted by the sweet potato whitefly, Bemisia tabaci (Gennadius), in a semi-persistent manner. Up to now, there is still lack of report in Hainan, the south of China. METHODS: We used observational and experimental methods to explore the prevalence and incidence dynamic of CCYV and ToCV transmitted by whiteflies in Hainan of China. RESULTS: In 2016, the chlorosis symptom was observed in the tomato and cucumber plants with a large number of B. tabaci on the infected leaves in Hainan, China, with the incidence rate of 69.8% and 62.6% on tomato and cucumber, respectively. Based on molecular identification, Q biotype was determined with a viruliferous rate of 65.0% and 55.0% on the tomato and cucumber plants, respectively. The weed, Alternanthera philoxeroides near the tomato and cucumber was co-infected by the two viruses. Furthermore, incidence dynamic of ToCV and CCYV showed a close relationship with the weed, Alternanthera philoxeroides, which is widely distributed in Hainan. CONCLUSION: Our results firstly reveal that the weed, A. philoxeroides is infected by both ToCV and CCYV. Besides, whiteflies showed a high viruliferous rate of ToCV and CCYV. Hainan is an extremely important vegetable production and seed breeding center in China. If the whitefly can carry these two viruses concurrently, co-infection in their mutual host plants can lead to devastating losses in the near future.
作者机构:
[Xie, Shang-Qian; Han, Yue; Xiao, Chuan-Le; Xie, Zhi; Chen, Kai-Ning; Wang, Yan] Sun Yat Sen Univ, Zhongshan Ophthalm Ctr, State Key Lab Ophthalmol, Guangzhou, Guangdong, Peoples R China.;[Xiao, Chuan-Le; Chen, Ying] Sun Yat Sen Univ, Sch Data & Comp Sci, Guangzhou, Guangdong, Peoples R China.;[Xiao, Chuan-Le; Chen, Ying] Sun Yat Sen Univ, Guangdong Prov Key Lab Computat Sci, Guangzhou, Guangdong, Peoples R China.;[Xiao, Chuan-Le] Hunan Agr Univ, Southern Reg Collaborat Innovat Ctr Grain & Oil C, Changsha, Hunan, Peoples R China.;[Xiao, Chuan-Le] Hunan Agr Univ, Coll Plant Protect, Changsha, Hunan, Peoples R China.
通讯机构:
[Xiao, CL; Xie, Z; Xiao, Chuan-Le] S;[Xiao, Chuan-Le] H;[Luo, Feng] C;Sun Yat Sen Univ, Zhongshan Ophthalm Ctr, State Key Lab Ophthalmol, Guangzhou, Guangdong, Peoples R China.;Sun Yat Sen Univ, Sch Data & Comp Sci, Guangzhou, Guangdong, Peoples R China.
摘要:
We present a tool that combines fast mapping, error correction, and de novo assembly (MECAT; accessible at https://github.com/xiaochuanle/MECAT) for processing single-molecule sequencing (SMS) reads. MECAT's computing efficiency is superior to that of current tools, while the results MECAT produces are comparable or improved. MECAT enables reference mapping or de novo assembly of large genomes using SMS reads on a single computer.
作者机构:
[Hu, Zhongli; Tan, Changjun; Diao, Ying; Zheng, Xingfei] Wuhan Univ, Coll Life Sci, Lotus Engn Res Ctr Hubei Prov, State Key Lab Hybrid Rice, Wuhan 430072, Peoples R China.;[Li, Lanzhi] Hunan Agr Univ, Coll Plant Protect, Hunan Prov Key Lab Biol & Control Plant Dis & Ins, Changsha 410128, Hunan, Peoples R China.;[Liang, Fan] Next Biosci, Wuhan 430075, Peoples R China.;[Tang, Shuzhu] Yangzhou Univ, Agr Coll, Yangzhou 225009, Jiangsu, Peoples R China.;[Yu, Sibin] Huazhong Agr Univ, Coll Plant Sci & Technol, Wuhan 430070, Peoples R China.
通讯机构:
[Hu, Zhongli] W;[Li, Shuangcheng] S;Wuhan Univ, Coll Life Sci, Lotus Engn Res Ctr Hubei Prov, State Key Lab Hybrid Rice, Wuhan 430072, Peoples R China.;Sichuan Agr Univ, Rice Inst, Chengdu 611130, Peoples R China.
摘要:
Rice breeding has achieved great productivity improvements by semi-dwarf varieties and hybrid vigour. Due to poor understanding of genetic basis of elite backbone varieties, the continuous increasing in rice yield still faces great challenges. Here, 52 elite rice varieties from three historical representative pedigrees were re-sequenced with 10.1x depth on average, and similar to 6.5 million single nucleotide polymorphisms (SNPs) were obtained. We identified thousands of low-diversity genomic regions and 0-diversity genes during breeding. Using pedigree information, we also traced SNP transmission patterns and observed breeding signatures in pedigree. These regions included the larger number of key well-known functional genes. Besides, 35 regions spanning 0.16% of the rice gnome had been differentially selected between conventional and restorer pedigrees. These genes identified here will be useful to the further pedigree breeding. Our study provides insights into the genetic basis of backbone varieties and will have immediate implications for performing genome-wide breeding by design.
摘要:
The current study investigated the impacts of temperature on the development and reproductivity of the sweet potato leaf folder, Brachmia macroscopa (Lepidoptera: Gelechiidae), in sweet potato leaves under laboratory conditions. We determined developmental time of B. macroscopa larval, pupal, and pre-adult stage at different temperatures. Male and female longevity, male and female lifespan, mortality of immature stages, oviposition period of B. macroscopa were also investigated under six constant temperatures (21°C, 24°C, 27°C, 30°C, 33°C, 36°C), based on age-stage, two-sex life tables. The results revealed that eggs in 36°C were unable to hatch. At temperatures between 21°C -33°C, the duration of the pre-adult period, as well as the adult lifespan both for males and females, were shortened by increasing temperatures. The lowest larval mortality rate (15.33%) occurred at 27°C. The age-stage-specific fecundity rates with the greatest number were, in order, 30°C, 27°C, 21°C, 24°C and 33°C. The results show that B. macroscopa population levels could reach highest at the temperature of 27℃.
摘要:
Alternaria brassicicola is one of the causal agents of alternaria blackspot in rapeseed. In this study, a dsRNA segment was isolated and sequenced from the fungus. The complete nucleotide sequence of the dsRNA was 2506 bp in length and, using the fungal mitochondrial genetic code, was predicted to contain a single large open reading frame (ORF) in the positive strand. This ORF was predicted to encode a protein with 719 amino acids that contains characteristic conserved motifs of the RNA-dependent RNA polymerase (RdRp). BLAST analysis revealed that this protein had significant sequence similarity to the RdRp from viruses of the genus Mitovirus. These results indicated that the dsRNA segment represents the replicative form of a mitovirus, which is tentatively designated "Alternaria brassicicola mitovirus 1" (AbMV1) and is a new member of the genus Mitovirus in the family Narnaviridae.
关键词:
*Microplitis similis, Spodoptera litura (F.);*food consumption;*host age preference;*weight gain
摘要:
Host selection is a key stage in the lifecycle of parasitoids, and is critical to both their function in control and to the maintenance of their population. The solitary endoparasitoid Microplitis similis (Hymenoptera: Braconidae) is a potential biological control agent of Spodoptera litura (F.) larvae (Lepidoptera: Noctuidae). In this study, we examined the preference M. similis exhibits for different instars of the host, host instar effects on parasitoid development, and the weight gain and food consumption of different instars of parasitized larvae. In no-choice tests, parasitization rates were highest in second- and early third-instar larvae, and no fourth- or fifth-instar hosts were parasitized. When provided with a choice of first- to late third-instar host larvae, M. similis preferred to parasitize early third-instar host larvae (41%) with a selection coefficient of 0.37. All morphometric features of wasp offspring increased with increasing age of the host at parasitization. A lower proportion of females emerged from first-instar larvae than any other instar. Parasitized S. litura larvae showed a pronounced reduction in food consumption and weight gain. Microplitis similis may have the potential to significantly suppress population growth and the damage caused by S. litura.
摘要:
The taxonomy of the Coilodera penicillata Hope, 1831 (Coleoptera: Scarabaeidae: Cetoniinae) species complex, which is recognized by the black body and elytra with larger tomentose maculae, is revised. Six Indochinese species assigned to this complex, including C. grandimaculata new species from Tibet, China. Coilodera nigroscutellaris Moser, 1902 revised status and C. formosana Moser, 1910 revised status formerly treated as two subspecies of C. penicillata Hope, 1831 are elevated to species rank. The distribution of C. penicillata in China is confirmed based on examination of specimens from Yunnan and Tibet, and almost all previous Chinese literature records should be referred to C. nigroscutellaris. Coilodera dives (Gory & Percheron, 1833) revised status previously synonymized with C. penicillata is herein considered as a valid species based on the examination of types and additional specimens, and C. miksici Antoine, 1986 new synonymy is regarded as a junior synonym of C. dives. A lectotype is designated for Coilodera dives (Gory & Percheron, 1833). The record of C. mearesii (Westwood, 1842) in southeastern China is attributed to a misidentification of C. nigroscutellaris, and it is here newly recoreded from Tibet near the Nepal-China border. Diagnosis characters and intraspecific variations are illustrated for all six species, new distribution records and a key to species are also presented. Ecological information is provided for all species.
摘要:
Ascoviruses are double-stranded DNA viruses that mainly infect noctuid larvae, and are transmitted by the parasitoid wasp Microplitis similis Lyle. Ascovirus-parasitoids wasp-noctuid insects constitute the dissemination system. Selection of suitable reference genes for the dissemination system could play an important role in elucidating the pathogenic molecular mechanisms of ascovirus. Unfortunately, such studies on potential reference genes in the dissemination system of ascoviruses are lacking. In the present study, we evaluated 11 candidate reference genes: beta-actin1 (ACT1), beta-actin2 (ACT2), elongation factor 1 (EF1), elongation factor 2 (EF2), ribosomal protein L10 (L10), ribosomal protein L17A (L17A), superoxide dismutase (SOD), 28S ribosome (28S), Tubulin (TUB) and 18S ribosome (18S). The samples were originally from various virus concentrations and points-in-time of experimental treatments using RefFinder and four algorithms. The results showed that EF1 was the most stable internal gene in S. exigua and M. similis and that EF2 was the most stable in the IOZCAS-Spex-II-A cell line, and the stability of reference genes were confirmed via the expression levels of two inhibitor of apoptosis-like (iap-like) genes from Heliothis virescens ascovirus 3 h (HvAV-3h). This study provides a crucial basis for future research that explores the molecular mechanisms of the pathogenesis of ascoviruses.
摘要:
Quinclorac is a widely used herbicide in rice filed. Unfortunately, quinclorac residues are phytotoxic to many crops/vegetables. The degradation of quinclorac in nature is very slow. On the other hand, degradation of quinclorac using bacteria can be an effective and efficient method to reduce its contamination. In this study, we isolated a quinclorac bioremediation bacterium strain F4 from quinclorac contaminated soils. Based on morphological characteristics and 16S rRNA gene sequence analysis, we identified strain F4 as Mycobacterium sp. We investigated the effects of temperature, pH, inoculation size and initial quinclorac concentration on growth and degrading efficiency of F4 and determined the optimal quinclorac degrading condition of F4. Under optimal degrading conditions, F4 degraded 97.38% of quinclorac from an initial concentration of 50 mg/L in seven days. Our indoor pot experiment demonstrated that the degradation products were non-phytotoxic to tobacco. After analyzing the quinclorac degradation products of F4, we proposed that F4 could employ two pathways to degrade quinclorac: one is through methylation, the other is through dechlorination. Furthermore, we reconstructed the whole genome of F4 through single molecular sequencing and de novo assembly. We identified 77 methyltransferases and eight dehalogenases in the F4 genome to support our hypothesized degradation path.
摘要:
The brown planthopper (BPH), Nilaparvata lugens (Stål), is a migratory and destructive sucking insect pest of rice. Silicon (Si) amendment to plants can confer enhanced resistance to herbivores and is emerging as a novel approach for pest management. In the present study, we tested the effects of Si addition at 0.16 (low) and 0.32 (high) g Si/kg soil on sucking behaviors and population growth in BPH. Si amendment increased Si content in rice stems and extended non-probing event and phloem puncture followed by sustained phloem ingestion over that in the no-Si-addition control. High Si addition rate prolonged the stylet pathway and the time needed to reach the first phloem puncture, shortened durations of phloem puncture and phloem ingestion, and decreased the proportion of individuals that produced sustained phloem ingestion. BPH female feeding on and preference for plants with the high Si addition rate were also reduced. As a result, Si application significantly decreased BPH population growth rates while increased population doubling time. These results indicate that Si amendment, especially at the high rate, confers enhanced rice plant resistance to BPH through impairment of BPH feeding. Our results highlight the potential of Si amendment as an alternative for BPH management.
摘要:
Deltamethrin belongs to the class of synthetic pyrethroids, which are being widely used as insecticides in agricultural practices. Voltage-gated sodium channels (VGSCs) are the primary targets of these chemicals for toxicity to insects. Caenorhabditis elegans (C. elegans) does not have VGSCs but is susceptible to deltamethrin. Recent findings have suggested that pyrethroids can affect voltage-gated calcium channels (VGCCs). However, it remains elusive whether deltamethrin induces toxicity to C. elegans via modulating the activity of VGCCs. To identify the potential target of deltamethrin, we exposed C. elegans to different concentrations of deltamethrin and Ca2+ channel blockers for different times, characterized the behavioral toxicity of deltamethrin on C. elegans, and determined the expression of egl-19, unc-2, and cca-1, which encode the alpha 1-subunit of the L-, R/N/P/Q-, and T-type VGCC, respectively. We found that deltamethrin inhibited the locomotion, egg-laying and foraging ability of C. elegans in a concentration dependent manner. We also showed that body length of worms on agar plates containing 200 mg L-1 deltamethrin for 12 h was not significantly different from controls, whereas the cholinesterase inhibitor carbofuran caused hypercontraction which is a characteristic of organophosphates and carbamates, suggesting that deltamethrin's mode of action is distinct from those nematicides. In addition, unc-2 was significantly up-regulated following 0.05 mg L(-1)deltamethrin exposure for 24 h; while egl-19 and cca-1 were significantly up-regulated following 5 and 50 mg L-1 deltamethrin exposure for 24 h. Further tests of worms' sensitivity and expression of three alpha 1-subunits of VGCC to Ca2+ channel blockers indicate that deltamethrin may induce toxic behavior C. elegans via modulation of the expression of the alpha 1-subunits of VGCC. This study provides insights into the linkage between deltamethrin-induced toxic behavior and the regulation of alpha 1-subunits of VGCC in C. elegans. (C) 2017 Elsevier Inc. All rights reserved.
摘要:
Parapoynx crisonalis is an important pest of many aquatic vegetables including water chestnuts. Understanding the relationship between temperature variations and the population growth rates of P. crisonalis is essential to predicting its population dynamics in water chestnuts ponds. These relationships were examined in this study based on the age-stage, two-sex life table of P. crisonalis developed in the laboratory at 21, 24, 27, 30, 33 and 36 degrees C. The results showed that the values of S-xj (age-stage-specific survival rate), f(xj) (age-stage-specific fecundity), l(x) (age specific survival rate) and m(x) (age-specific fecundity) increased as the temperature rose from 21 to 27 degrees C, then decreased from 30 to 36 degrees C. Temperature also had a significant effect on the net reproductive rate (R-0), gross reproductive rate (GRR), intrinsic rate of increase (r) and finite rate of increase (gimel.). The value of these parameters were at low levels at 21, 33, and 36 degrees C. Further, the r value decreased as the temperature rose from 24 to 30 degrees C, while the GRR reached its highest level at 27 degrees C. The results indicated that optimal growth and development of P. crisonalis occurred at temperatures between 24 degrees C to 30 degrees C when compared to the lowest temperature (21 degrees C) and higher temperatures of 33 degrees C and 36 degrees C.
摘要:
Burning straw in the field is a common agricultural practice. The effects of adding biochar derived from rice straw to soils on the phytotoxicity of sulfentrazone to Oryza sativa L. were observed. Overall, when 1 % biochar was added to three different soils, the phytotoxicity of sulfentrazone to O. sativa L. decreased, and the concentration that inhibits growth by 50 % (IC50) increased by 1.4 to 7.6 times. To illuminate the influencing mechanisms, the changes in sulfentrazone adsorption to the soil, the soil pH, and the bioavailable sulfentrazone extracted from the soil solution using hollow fiber-based liquid-phase microextraction were studied. The Freundlich constant (K
f
) of sulfentrazone to the soil increased 1.5 to 25 times relative to the K
f
in the three unamended soils, and the soil pH increased by 0.36 to 1.36 units resulted in a fraction of dissociated sulfentrazone increased by 10.2–17.4 %. In addition, the average concentrations of sulfentrazone in the three unamended soil solutions were 1.3–6.1 times relative to those in the three biochar-amended soil solutions. These results suggest that the sulfentrazone adsorption and soil pH increased when soils were amended with biochar, which decreased the bioavailable concentrations and reduced its phytotoxicity to O. sativa L.