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Niu J.H.,China Agricultural University | Niu J.H.,Tropical Crops Genetic Resources Institute | Jian H.,China Agricultural University | Guo Q.X.,China Agricultural University | And 4 more authors.
Plant Pathology | Year: 2012

A loop-mediated isothermal amplification (LAMP) assay for detection of Meloidogyne enterolobii (Me-LAMP) was developed based on the sequences of the 5S ribosomal DNA (5S rDNA) and intergenic spacer 2 (IGS2) segment. The LAMP amplification was achieved at 65°C isothermal conditions within 1-1·5h. Its amplicons were confirmed using gel electrophoresis, SacI enzyme analysis, lateral flow dipstick (LFD) assay, and visual inspection through SYBR Green I and calcein staining. The results demonstrated that the Me-LAMP was able to specifically detect M. enterolobii populations from different geographical origins, with a detection limit of about 10fg M. enterolobii genomic DNA, which was 10-100 times more sensitive than conventional PCR. In addition, the applicability of LAMP to field detection was confirmed following its successful performance in detecting the pest on root and soil samples. The Me-LAMP assay possessed the characteristics of simplicity, sensitivity and specificity, and is a promising and practical molecular tool for M. enterolobii diagnosis in pest quarantine and field surveys. © 2011 The Authors. Plant Pathology © 2011 BSPP. Source

Niu J.,China Agricultural University | Niu J.,Tropical Crops Genetic Resources Institute | Jian H.,China Agricultural University | Xu J.,China Agricultural University | And 4 more authors.
European Journal of Plant Pathology | Year: 2012

RNA interference (RNAi) techniques provide a major breakthrough in functional analysis for plant parasitic nematodes (PPNs). It offers the possibility of identifying new essential targets and consequently developing new resistance transgenes. To validate the potential of Mi-Rpn7 as a target for controlling root knot nematode Meloidogyne incognita and to evaluate the feasibility of our modified platform for assessing silencing phenotypes, we knocked down the Rpn7 gene of M. incognita using RNAi in vitro and in vivo. After soaking with 408-bp Rpn7 dsRNA, pre-parasitic second-stage juvenile (J2) nematodes showed specific transcript knockdown, resulting in an interrupted locomotion in an attraction assay with Pluronic gel medium, and consequently in a reduction of nematode infection ranging from 55. 2% to 66. 5%. With in vivo expression of Rpn7 dsRNA in transformed composite plants, the amount of egg mass per gram root tissue was reduced by 34% (P < 0. 05) and the number of eggs per gram root tissue was reduced by 50. 8% (P < 0. 05). Our results demonstrated that the silencing of the Rpn7 gene in M. incognita J2s significantly reduced motility and infectivity. Although it does not confer complete resistance, Mi-Rpn7 RNAi in hairy roots produced significant negative impacts on reproduction and motility of M. incognita. In addition, the presented modified procedure provides technique reference for PPN genes functional analysis or target screening. © 2012 KNPV. Source

Wang Q.,Shandong Agricultural University | Wang Q.,Shandong Academy of Agricultural Sciences | Jiang Z.-F.,University of Chicago | Wang N.-X.,Shandong Agricultural University | And 4 more authors.
Ecology and Evolution | Year: 2013

Host-parasites interaction is a common phenomenon in nature. Diffusive coevolution might maintain stable cooperation in a fig-fig wasps system, in which the exploiter might diversify their genotype, phenotype, or behavior as a result of competition with pollinator, whereas the figs change flower syconia, fruits thickness, and syconia structure. In functionally dioecious Ficus auriculata, male figs and female figs contain two types of florets on separate plant, and share high similarities in outside morphology. Apocryptophagus (Sycophaginae, Chalcidoidea, Hymenoptera) is one of few groups of nonpollinating fig wasps that can reproduce within both male and female figs. On the basis of the morphology and DNA barcoding, evidence from partial sequences of mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2, we found that there are two nonsibling Apocryptophagus species living on male and female F. auriculata figs, respectively. We estimated that these two species diverged about 19.2 million years ago. Our study suggests that the host shift from Ficus variegate or Ficus prostrata fig species to male figs is a preference way for Apocryptophagus wasps to adapt to the separation of sexual function in diecious figs. Furthermore, to escape the disadvantage or sanction impact of the host, the exploiter Apocryptophagus wasps can preferably adapt to exploiting each sex of the figs, by changing their oviposition, niche shift, and habitat. It describes empirical research into fig wasp divergence, in functionally dioecious Ficus species, two nonsibling Apocryptophagus species showed sex-specific parasite. © 2013 The Authors. Source

Hou G.,Tropical Crops Genetic Resources Institute | Hou G.,Chinese Academy of Agricultural Sciences | Huang M.,Chinese Academy of Agricultural Sciences | Gao X.,Chinese Academy of Agricultural Sciences | And 4 more authors.
African Journal of Biotechnology | Year: 2011

Calpain 1 (CAPN1) and its activator HRSP12 are evaluated as candidate gene for quantitative trait loci (QTLs) affecting meat tenderness. In this study, SNPs were detected by sequencing in 323 cattle from 9 breeds. The association results showed that the A3553G and T824C loci individually related with marbling and tenderness, and CAPN1/HRSP12 double homozygote and heterozygote/homozygote pairs (AA/TT, AA/CC, AG/TT and GG/TT) had higher marbling score than the other groups. Our findings suggest that polymorphisms in CAPN1 and HRSP12 might be the important genetic factor influencing meat quality in carcass trait. Source

Hou G.-Y.,Tropical Crops Genetic Resources Institute | Zhao J.-M.,Chinese Institute of Scientific and Technical Information | Zhou H.-L.,Tropical Crops Genetic Resources Institute | Rong G.,Tropical Crops Genetic Resources Institute
Acta Tropica | Year: 2016

In the present study, the seroprevalence, risk factors and genotyping of Toxoplasma gondii in masked palm civet were investigated in tropical China. A total of 500 serum were collected from five administrative farms in tropical China, and assayed for T. gondii antibodies by modified agglutination test (MAT). The brain samples of 20 aborted fetuses were examined by semi-nested-PCR, and positive aborted fetuses (50%) were necropsied to collect the brain tissue for molecular and bioassay examinations. Genomic DNA was extracted from the 29 brain tissues of infected mice and T. gondii B1 gene was amplified using multilocus PCR-RFLP. Overall, 27.6% (95% CI: 23.682–31.518) of the animals was positive for T. gondii antibodies. Ages of masked palm civet was considered as a main risk factor associated with T. gondii infection. 4 DNA samples (13.8%) were positive for the T. gondii B1 gene. Three samples belong to ToxoDB#9, and one belongs to genotype the type II variant (ToxoDB genotype#3). Our results indicated that ToxoDB Genotype#9 has a distribution in masked palm civet that could be potential reservoirs for T. gondii transmission, which may pose a threat to human health. © 2016 Source

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