摘要：
A novel, simple, rapid and highly sensitive assay and diagnostic tool for the burrowing nematode, Radopholus similis, was developed using a loop-mediated isothermal amplification (LAMP). The LAMP assay was targeted on the specific fragments of rRNA gene D2-D3 regions of R. similis. The detection limitation of the LAMP assay was as low as ten copies of plasmid DNA containing the target DNA, 10 fg of genomic DNA and 5 x 10(-5) nematodes. The detection sensitivity of the LAMP method for R. similis DNA was 10-100 times higher than normal PCR-based detection methods. The LAMP amplifications could be observed directly by eye by adding SYBR Green! and the lateral flow dipstick (LFD). LAMP assay for R. similis is a practical and useful diagnostic tool for early diagnosis of plant tissues infested by R. similis. The LAMP assay developed in this study is highly effective, easy to perform and readily adaptable for diagnostic and monitoring of the R. similis-diseased seedling in the field.
摘要：
Brevibacillus brevis X23 is an appropriate biocontrol agent against bacterial wilt caused by Ralstonia solanacearum. We report herein the draft genome sequence (6,566,879 bp) and a circular plasmid (6,600 bp) of B. brevis X23, data which may be helpful for mining the antagonistic activity against R. solanacearum.
作者：
Yajun Peng;Lifeng Wang;Xiaomei Cheng;Lianyang Bai
作者机构：
[Yajun Peng; Lifeng Wang; Xiaomei Cheng] College of Biosafety Science and Technology, Hunan Agricultural University, Changsha , Hunan, China;[Lianyang Bai] College of Biosafety Science and Technology, Hunan Agricultural University, Changsha , Hunan, China ＃@＃Hunan University of Humanities, Science and Technology, Loudi, Hunan, China
会议名称：
The 6th International Weed Science Congress(第六届国际杂草科学大会)
会议时间：
2012-6-17
会议地点：
杭州
会议主办单位：
中国植物保护学会
会议论文集名称：
The 6th International Weed Science Congress(第六届国际杂草科学大会)论文集
摘要：
为解决无法用文字实现对近千种连续变化的昆虫体色进行准确的描述和合理的数学运算问题,本文采用国际标准颜色计量技术-PFG（Pantone Formula Guide）颜色指南为昆虫体色性状判别标准,提出了关于数值化描述昆虫体色的相关评价指标,如体色元（body-colorelement,BCE）、体色群（body-color group,BCG）、体色位（body-colorposition,BCP）、高频色码指数（high frequency color-code index,HFI）和杂色指数（variegated color index,VCI）等及其定量分析方法。并应用这些指标和方法,研究了甘薯天蛾Agrius convolvuli幼虫个体在相似环境条件下体色分化的多样性以及不同发育日龄和不同虫体部位（体位）其体色的演化过程及其数值规律,发现甘薯天蛾幼虫存在着共同的主体色,而且其体色的变异主要发生在个体的不同发育日龄（占总变异的72.66%）,其次,虫体不同部位的颜色也有明显的差异（占总变异的24.45%）,而同一发育日龄个体间的体色差异仅占总变异的2.88%。结果说明,甘薯天蛾幼虫体色随其发育日龄所发生的变化过程,可能是由遗传因子所决定的一种生命体从发育到衰老的表观呈现过程。
关键词：
Andraca;Bombycidae;new subspecies;nueva subespecie;South China;sur de China;Taxonomía;taxonomy
摘要：
The Chinese Andraca is revised with the check-list annotated. A new bombycid geographic subspecies, Andraca nobilorum houtuae Wang & Zolotuhin subsp. nov., is described from Damingshan National Nature Reserve, South China. The new subspecies differs from the nominate A. nobilorum. in Central Vietnam by the darker marker at the apex of the forewing indistinct but prominent in the holotype of A. nobilorum, and its male genitalia with the apex of valva slenderer and pointed. A key to the Chinese Andraca species and Pseudandraca flavamaculata, and the distributional maps are given. The male holotype specimen of the new subspecies is deposited in SCAU (South China Agricultural University, Guangzhou, China).
作者机构：
[Fu, Y.; Zhang, S.; Liao, X.] Univ Florida, IFAS, Ctr Trop Res & Educ, Homestead, FL 33031 USA.;[Liao, X.] Hunan Agr Univ, Coll Biosafety Sci & Technol, Changsha 410128, Hunan, Peoples R China.;[Duan, Y. P.] ARS, US Hort Res Lab, USDA, Ft Pierce, FL 34945 USA.
通讯机构：
[Liao, X.] U;Univ Florida, IFAS, Ctr Trop Res & Educ, Homestead, FL 33031 USA.
摘要：
Indian spinach (Basella rubra L.) is a red stem species of Basella that is cultivated worldwide as an ornamental and the aerial parts are also consumed as a vegetable. In May of 2011, symptoms of damping-off were observed on approximately 10% of the plants at the stem base around the soil line of seedlings in a greenhouse in Homestead, FL. Lesions were initially water soaked, grayish to dark brown, irregular in shape, and sunken in appearance on large plants, causing the infected seedlings to collapse and eventually die. Symptomatic stem tissue was surface sterilized with 0.6% sodium hypochlorite, rinsed in sterile distilled water, air dried, and plated on potato dextrose agar (PDA). Plates were incubated at 25 degrees C in darkness for 3 to 5 days. A fungus was isolated in all six isolations from symptomatic tissues on PDA. Fungal colonies on PDA were light gray to brown with abundant growth of mycelia, and the hyphae tended to branch at right angles when examined under a microscope. A septum was always present in the branch of hyphae near the originating point and a slight constriction at the branch was observed. Neither conidia nor conidiophores were found from the cultures on PDA. The characteristics of hyphae, especially the right angle branching of mycelia, indicate close similarity to those of Rhizoctonia solani (2,3). The internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced (GenBank Accession No. JN545836). Subsequent database searches by the BLASTN program indicated that the resulting sequence had a 100% identity over 472 bp with the corresponding gene sequence of R. solani anastomosis group (AG) 4 (GenBank Accession No. JF701752.1), a fungal pathogen reported to cause damping-off on many crops. Pathogenicity was confirmed through inoculation of healthy India spinach plants with the hyphae of isolates. Four 4-week-old plants were inoculated with the isolates by placing a 5-mm PDA plug of mycelia at the stem base and covering with a thin layer of the soil. Another four plants treated with sterile PDA served as a control. After inoculation, the plants were covered with plastic bags for 24 h and maintained in a greenhouse with ambient conditions. Four days after inoculation, water-soaked, brown lesions, identical to the symptoms described above, were observed on the stem base of all inoculated plants, whereas no symptoms developed on the control plants. The fungus was isolated from affected stem samples, and the identity was confirmed by microscopic appearance of the hyphae and sequencing the ITS1/ITS4 intergenic spacer region, fulfilling Koch's postulates. This pathogenicity test was conducted twice. R. solani has been reported to cause damping-off of B. rubra in Ghana (1) and Malaysia (4). To our knowledge, this is the first report of damping-off caused by R. solani AG-4 on Indian spinach in Florida and the United States. With the increased interest in producing Asian vegetables for food and ornamental purposes, the occurrence of damping-off on Indian spinach needs to be taken into account when designing programs for disease management in Florida. References: (1) H. A. Dade. XXIX. Bull. Misc. Inform. 6:205, 1940. (2) J. R. Parmeter et al. Phytopathology 57:218, 1967. (3) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St Paul, MN, 1991. (4) T. H. Williams and P. S. W. Liu. Phytopathol. Pap. 19:1, 1976.
摘要：
A simplified version of the QuEChERS method for the extraction of quinclorac from soil samples was proposed. Optimum results were obtained dispersing soil in water, followed by the addition of 1 % acetic acid in acetonitrile, magnesium sulfate and sodium acetate as a modification of the quick, easy, cheap, effective, rugged and safe (QuEChERS) method. Liquid chromatography/ultraviolet (LC-UV) detector was then used to analyze the extracts without any other sample pretreatment. The result showed the recovery ranged from 73.8 to 106.4 % and 66.6 to 87.3 % with the relative standard deviations of 1.9 to 15.7 % and 4.7 to 9.3 % in two soil samples, respectively. The limit of detection (LOD) of the method was 0.05 mg kg -1. The limit of quantification (LOQ) was 0.5 mg kg -1. The half life period of quinclorac was 65.7 and 36.5 days in soil of Changsha and Nanning in China, respectively.
摘要：
Sheath blight, a disease caused by the fungus Rhizoctonia solani Kuhn (anamorph), has been the most economically significant disease of rice. It was frequently reported that the disease was well-controlled in integrated rice-duck system without the employment of fungicides. However, the effecting factors behind this phenomenon were rarely reported. In this research, experiment was carried out between two treatments, rice combined with ducks (RD) and conventional rice field without ducks rearing (CK) in early season rice paddy, to investigate the variations of sclerotia in floodwater and on rice plant, microclimate 10 cm above the waterline in rice paddy and activity of protective enzymes in rice plants. The results showed that the floating sclerotia in floodwater in RD was 86-91% lower than that in CK, and adhering sclerotia in rice plant in RD was 67-78% lower than that in CK. The relative humidity tested significantly lower and light intensity tested significantly higher in RD. The temperature in the early rice growth stages in RD was slightly lower than that in CK, but it was significantly higher (32.3-36.5°C) in the middle stage rice growth stages. The polyphenoloxidase (PPO) activity in RD were lower than that in CK, but the enhanced activity of phenylalanine ammonia-lyase (PAL), peroxidase (POD) and Chitinase was observed in different stages of rice growth in RD, especially the Chitinase which showed higher activity in all investigating days.
