水杨酸诱导山茶抗灰斑病的作用及生理生化响应

采用载玻片萌发法测定水杨酸(SA)对山茶灰斑病菌的影响。浓度为0～5mmol.L-1的SA对山茶灰斑病菌的孢子萌发没有抑制作用,其诱发抗病性可持续10～15天,诱导最佳间隔期为3天。用SA喷雾涂布叶片诱导山茶抗性,植株内丙二醛、木质素、可溶性蛋白含量等生化指标对山茶灰斑病菌诱导信号有不同响应。MDA含量在一定时间范围内减少,膜脂的过氧化程度降低,但随着处理时间的延长,这种诱导抗性的作用逐渐减弱,且在不同浓度处理间存在差异,在诱导并挑战接种的处理中,各处理表现为初期低于对照、后期缓慢上升;诱导并挑战接种的处理中,木质素含量的变化趋势与只诱导处理基本相似,高浓度诱导的木质素积累量大于低浓度;诱导并挑战接种处理的可溶性蛋白含量与只诱导处理也表现出相同的变化规律,诱导并挑战接种处理的可溶性蛋白含量比只诱导的处理和对照高。生化反应与病情指数的相关性分析表明:MDA、木质素含量与病情指数达到显著水平(P<0.05)。     

neo-Clerodane diterpenes from Ajuga decumbens and their inhibitory activities on LPS-induced NO production

A phytochemical investigation of the whole plants of Ajuga decumbens led to the isolation of three new (1, 2a, and 2b) and three known (3a−3c) neo-clerodane diterpenes. Their structures were elucidated by spectroscopic data analysis (IR, ESIMS, HR-ESIMS, 1D and 2D NMR), and the structure of 1 was confirmed by X-ray crystallography. The inhibitory activities on LPS-induced NO production of the six diterpenes were evaluated and compounds 2a, 2b, and 3a showed inhibitory effects.     

A蛋白间接酶联免疫法对杂交竹梢枯病菌蛋白毒素的检测

采用A蛋白双抗夹心法,在包被抗血清前先用A蛋白包被微量测定板,利用A蛋白抗血清中免疫球蛋白的FC部位结合,以F(ab’)2部位吸附抗原毒素,在被吸附的毒素上再加一层相同的抗血清和酶标记的A蛋白,以检测杂交竹梢枯病菌毒素蛋白。结果表明:A蛋白预包被能提高检测效价,降低本底值。抗原浓度对酶联检测有显著影响,纯毒素稀释倍数大于10-6,检测结果与对照接近,不适宜用于检测。OD值随抗原稀释倍数的增加下降,且下降幅度受测定抗血清浓度的影响;当检测液稀释1∶5(1∶50时,测定抗血清浓度在10-4(病株汁液)和10-6(含毒素发酵液)时可测出显著差别。抗血清浓度为10-4下,含毒素发酵液在标记A蛋白浓度为1∶10(1∶640范围内有较好测定结果,而病株汁液在标记A蛋白浓度为1∶10(1∶160才能测出。本研究首次将此技术用于真菌毒素检测中,该方法对杂交竹病株汁液中的致病毒素有高度的特异性和灵敏度,能早期诊断暗孢节菱孢菌引起的杂交竹梢枯病。     

Flammability Ranking of Major Species of Trees and Shrubs in Daxing’anling Area of Northeastern China

Factor analysis and expert scoring methods were used to rank flammability of 16 major species of trees and shrubs in Daxing’anling area of northeastern China,based on 6 flammability variables,i.e.,air dry moisture content,absolute dry moisture content,ignition point,ash content,heat of combustion and extractive content measured on leaves,barks and twigs.Out of 16 species evaluated,for leaves’ flammability,Larix gmelini was the smallest and Pinus sylvestris var.mongolica was the biggest;for barks’ flammability,Salix koreensis was the smallest and P.sylvestris var.mongolica was the biggest;and for twigs’ flammability,Populus davidiana was the smallest and Ledum palustre var.dilatatum was the biggest.The flammability ranking based on the integrated scores of leaves,barks and twigs suggested that Prunus padus,Betula dahurica,and L.gmelini were the top 3 less flammable species and that L.palustre var.dilatatum,P.sylvestris var.mongolica,and R.simsii were the top 3 more flammable species.This ranking agreed well with current standards and experience and should help the species selection for building fire-break forest belts in the study region.     

A multidimensional analysis of marine capture fisheries in China’s coastal provinces

Fisheries Science - China (herein referred as China’s mainland, and excluding Hong Kong, Macau and Taiwan) is the largest contributor to global seafood production. While China’s marine...     

运城黄河湿地景观空间格局变化及其驱动因素

基于2007-2017年5期遥感影像,运用遥感解译和景观指数方法,探究运城黄河湿地景观格局变化及其驱动因素,为黄河中游河道湿地的修复与可持续利用提供参考。结果表明:(1)湿地面积在2007-2017年期间总体呈增长趋势,其中2007-2015年湿地面积持续上升,面积增加9 041.39 hm^2,2015-2017年减少5 716.08 hm^2。湿地与旱地之间转换最密切,湿地景观间(水域+沼泽+草甸)也有较大幅度的转换。景观类型的分布以河津市、万荣县、永济市及垣曲县部分种类偏多,湿地景观沿河流分布。(2)类型水平上,旱地是优势类型,湿地整体处于劣势,景观零碎。水域在湿地景观中占优势,林地、旱地景观趋于复杂,旱地、水域、林地景观集聚度偏大;景观水平上,研究区景观破碎度和复杂度都有不同程度的降低,结构趋于稳定,连通性变好。(3)景观格局变化主要受人为驱动影响,其中政策对研究区有强制性的作用。近10 a运城黄河湿地呈现增长态势,景观格局总体逐渐优化。     

Porcine sirtuin 1 gene clone, expression pattern, and regulation by resveratrol

Sirtuin1 (Sirt1) is a NAD-dependent deacetylase that plays important roles in a variety of biological processes. In the current study, we examined tissue-specific and different expression pattern of porcine Sirt1 and the effect of resveratrol (RES) on expression of Sirt1 in porcine adipocytes. The full-length complementary DNA sequence of porcine Sirt1 was 4,024 bp (GenBank accession no: EU030283), with a 2,226-bp open reading frame encoding a 742-AA protein (a predicted molecular mass of 80.9 kDa; GenBank accession no. ABS29571). Comparison of the deduced AA sequence with the corresponding sequences of human, dog, cattle, and mouse Sirt1 showed 82 to 92% similarity. Furthermore, the porcine Sirt1 was highly expressed in porcine brain, to a lesser degree in spleen and white adipose tissue, and had low but detectable expression in liver. In subcutaneous adipose tissue and omental adipose tissue, expression of the porcine Sirt1 mRNA was greater in adult pigs than in young pigs (P < 0.01). In vitro, exposure of cultured adipocytes to 40 and 80 micro M RES for 24 h increased mRNA levels of porcine Sirt1 by 47.86% (P < 0.01) and 91.04% (P < 0.01), respectively. Accordingly, lipid accumulation and NEFA release were decreased (P < 0.05), respectively. After cultures were treated with RES for 48 h, the mRNA level of porcine Sirt1 was increased by 103.84% (P < 0.01) and 148.79% (P < 0.01), respectively. Lipid accumulation was decreased and NEFA release was increased (P < 0.05), respectively. These results provide information needed for manipulating Sirt1 expression in regulating fat deposition in pigs.     

实时荧光RT-PCR快速检测猪源性食品中猪瘟病毒的研究

为快速检测食品中的猪瘟病毒(CSFV),本研究参照GenBank中登录的CSFV序列,设计引物及特异性TaqMan探针,利用实时荧光PCR技术,以质粒作为阳性标准品,建立特异、敏感、重复性好的CSFV快速定量检测方法.用本方法对几种不同猪源性食品(盐渍肠衣、鲜肉和腌肉)中的CSFV进行检测,结果显示该方法比普通RT-PCR具有更高的敏感性.本研究表明,该实时荧光RT-PCR能用于猪源性食品中的CSFV检测.为快速、准确检测动物源性食品中CSFV提供一条新途径.     

红壤侵蚀区花岗岩地质地貌对水土流失的影响

长汀是我国南方花岗岩地区水土流失最为严重的区域之一。花岗岩由于本身岩体特性,形成的风化壳结构松散,抗侵蚀能力弱。发育在花岗岩上的土壤剖面具有显著的层次结构,各层次的颗粒组成、有机质含量都有很大的差异,不同层次土壤的抗侵蚀性能也因此有很大的差异。坡度、坡长等地貌因素也对水土流失有较大的影响。经过多年有效的治理长汀水土流失面积大为减少,但和全省其他地方相比,水土流失仍然严重。本文对前人研究治理长汀水土流失的过程中,关于地质地貌对水土流失的影响方面所取得一些经验进行归纳,并提出一定的建议,以期对水土流失的治理提供借鉴。     

两次投加竹炭对UASB反应器污泥颗粒化的促进作用

为考察竹炭不同投加方式对UASB反应器污泥颗粒化过程的影响,以猪场废水为培养基质,对比分析了试验组（启动初期和颗粒污泥形成后两次投加粉末竹炭）和对照组（仅在启动初期投加1次粉末竹炭）两台UASB反应器中污泥颗粒化过程。结果表明：在颗粒污泥出现后再次投加粉末竹炭可促进颗粒污泥的增殖与稳定,有利于大粒径颗粒污泥的形成和致密化,改善颗粒污泥沉降性能,进而提高有机物去除效果。试验运行至第57 天,试验组反应器底部和上部污泥颗粒化程度（SGR）分别为94.5%和60.7%,比对照组分别高出了7.9%和17.3%,其中试验组反应器底部粒径大于 1.7 mm的颗粒污泥质量分数达到了41.7%,而对照组仅为32.4%;试验组反应器化学需氧量（COD）去除率为81.6%,明显高于对照组（75.7%）。试验结果证明,在UASB污泥颗粒化过程中,于颗粒污泥出现后再次投加粉末竹炭,可加快UASB 反应器的启动。