桑树花青素合成酶(ANS)基因的克隆及在2种果色桑树中的表达特征

花青素合成酶(anthocyanidin synthase,ANS)是植物花青素生物合成途径末端的关键酶,催化无色花色素到有色花色素的转变。从广东桑品种粤椹大10中克隆得到一条ANS序列,其ORF为1 077 bp,编码358个氨基酸,预测蛋白质分子质量为41 kD,等电点为5.62,具有2-酮戊二酸双加氧酶的保守结构域。多重序列比对表明物种间的ANS序列高度保守,系统进化树中桑树ANS与芍药科、芸香科、葡萄科等植物的同源序列聚在一个类群上。RT-PCR检测桑树ANS在结紫色果的粤椹大10的幼叶和桑椹中特异性表达,并且随着果色加深其表达水平呈上升趋势,而在结白色果的桑品种珍珠白的幼叶和桑椹中检测不到ANS的表达,暗示桑树ANS在桑椹的颜色形成中起到重要作用。     

3种喷雾助剂对呋虫胺防治苹果黄蚜的增效作用

采用室内毒力测定、助剂润湿铺展性能和田间效果评价研究了3种功能助剂NF-100、GY-T1602和迈道对呋虫胺防治苹果黄蚜的减施增效作用。结果表明,NF-100、GY-T1602和迈道3种助剂均未能提高呋虫胺对苹果黄蚜的毒力;20%呋虫胺SG 1 110～5 000倍液中分别添加0.1%NF-100、0.5%GY-T1602和0.3%迈道,表面张力降低6.97～37.44 mN/m、静态接触角降低10.58°～48.67°、黏附张力增加2.32～21.71 mN/m; 20%呋虫胺SG(有效成分用量32 mg/kg)减量处理添加3种助剂药后3～15 d对苹果黄蚜田间防效达90.83%～99.33%,其中添加NF-100和GY-T1602药后15 d防效均显著高于添加迈道处理及20%呋虫胺SG(40 mg/kg)未减量处理。因此,喷雾助剂NF-100和GY-T1602可显著改善呋虫胺药液的润湿铺展性能,减少呋虫胺有效成分用量20%,对苹果黄蚜仍有较高防效、且持效期延长。     

菊花18个品种的RAPD分析

 采用RAPD 技术分析了18 个菊花品种DNA 的多态性。从80 个10 碱基随机引物中筛选出多态性频率高的3 个引物。扩增的多态性片段在600 bp～1300 bp 之间。检测出两个品种特有的分子标记, ‘大红托桂’有OPD15 (1200 bp) ,‘玉翎管’缺失OPA17 (1100 bp) 。瓣型一致的品种间基因型相似系数较高。     

黏虫体内两种微管蛋白基因cDNA序列的克隆与序列分析

以黏虫4龄幼虫为材料提取总RNA,利用RT-PCR和cDNA末端快速扩增技术(RACE),分别扩增得到该虫的α和β微管蛋白基因的cDNA序列各1条。其中α微管蛋白基因的cDNA序列1 443个碱基,包括一个1 353个碱基的开放阅读框,编码一个含450个氨基酸的蛋白,分子量约为50.0ku。氨基酸的142~148位存在一个微管蛋白标志信号片段GGGTGSG,在氨基酸序列的C-端有一个酪氨酸残基,N-端存在一个对转录后调控非常重要的保守区MRECI序列,以上特点与其他昆虫α微管蛋白氨基酸序列相同。黏虫β微管蛋白基因cDNA序列含1 906个碱基,开放读码框1 344个碱基,编码氨基酸447个,分子量约为50.2ku,等电点4.75。1~4个氨基酸MREI为β微管蛋白转录后调控信号,140~146GGGTGSG位同样存在一个微管蛋白标志信号片段。序列比对表明,克隆的α和β微管蛋白基因与其他昆虫的α和β微管蛋白基因在核苷酸和氨基酸水平上都是高度同源的,黏虫与家蚕(Bombyx mori)α微管蛋白的氨基酸序列同源性达到99.3%,与其他3种夜蛾科昆虫α微管蛋白的氨基酸序列同源性更是达到100%。黏虫与家蚕β微管蛋白的氨基酸序列同源性达到98.7%,与烟草天蛾β微管蛋白的氨基酸序列同源性达到99.6%。两个基因的cDNA序列已经登录GenBank并获得登录号分别为EU100016和EU234504。     

饲料脂肪水平对拟穴青蟹仔蟹生长性能、体组成及消化酶活性的影响

本试验以初始体重为(0.042±0.002)g的拟穴青蟹仔蟹为研究对象,以鱼油和大豆油(1∶1)为脂肪源,配制脂肪水平分别为1.93%、3.95%、6.35%、8.14%、10.54%、12.30%、14.22%(实测值)的7种等氮等能试验饲料,养殖期为3周,用以研究饲料脂肪水平对拟穴青蟹仔蟹生长性能、体组成及消化酶活性的影响。每100只拟穴青蟹仔蟹为1个重复,每3个重复饲喂1种试验饲料。结果表明:1)饲料脂肪水平对拟穴青蟹仔蟹的增重率和特定生长率有显著影响(P0.05)。随着饲料脂肪水平的升高,增重率和特定生长率均呈先增后降的趋势,在饲料脂肪水平为8.14%时,增重率和特定生长率达到最大值。二次曲线回归分析确定当增重率达到最大值时,饲料脂肪水平为7.52%。拟穴青蟹仔蟹的成活率在饲料脂肪水平为14.22%的组最低,显著低于其余各组(P0.05)。2)饲料脂肪水平对全蟹中粗蛋白质和粗脂肪含量有影响显著(P0.05)。全蟹粗蛋白质含量随着饲料脂肪水平的升高先升后降,在饲料脂肪水平为8.14%的组全蟹粗蛋白质含量达到最高;全蟹粗脂肪含量则随着饲料脂肪水平的升高而持续上升,在饲料脂肪水平为14.22%的组全蟹粗脂肪含量达到最高。饲料脂肪水平对全蟹中水分和粗灰分含量没有显著影响(P0.05)。3)随着饲料脂肪水平的升高,拟穴青蟹仔蟹蛋白酶、淀粉酶和脂肪酶活性均呈先增后降的趋势,3种酶活性的最大值均出现在饲料脂肪水平为8.14%的组。由此得出,以增重率为评价指标,拟穴青蟹仔蟹饲料中最适脂肪水平为7.52%。     

温度、食料条件对白背飞虱种群增长的影响

白背飞虱若虫和全世代发育速率与温度的关系呈逻辑斯谛关系,成虫产卵前期和卵的发育速率与温度的关系呈二次抛物线关系。在18—30℃下,卵孵化率比较稳定,水稻生育期对卵孵化亦无明显影响,孵化率平均为86.96％。若虫存活率、成虫产卵量和内禀增长力受温度和食料条件的影响十分明显,取食分蘖期和拔节期水稻的若虫存活率最高,成虫产卵量和内禀增长力最大。在水稻各生育期,若虫存活率、成虫产卵量和内禀增长力与温度的关系呈抛物线趋势。当温度达到35℃时,各生育期卵孵化率均下降到50％以下,且若虫陆续全部死亡。     

Suppression subtractive hybridization and microarray analysis reveal differentially expressed genes in the <Emphasis Type="Italic">Lr39/41</Emphasis>-mediated wheat resistance to <Emphasis Type="Italic">Puccinia triticina</Emphasis>

Wheat leaf rust caused by Puccinia triticina (Pt) is one of the most severe fungal diseases threatening the global wheat production. The use of leaf rust resistance (Lr) genes in wheat breeding programs is the major solution to solve this issue. Wheat isogenic line carrying the Lr39/41 gene has shown a moderate to high resistance to most of the Pt pathotypes detected in China. In the present study, a typical hypersensitive response (HR) was observed using microscopy in leaves of the Lr39/41 isogenic line inoculated with the avirulent Pt pathotype THTT from 48 h-post inoculation. Two Lr39/41 resistance-associated suppression subtractive hybridization (SSH) libraries with a total of 6000 clones were established. Microarray hybridizations were performed on all obtained SSH clones using RNAs extracted from leaves of the Pt-inoculated and non-inoculated Lr39/41 isogenic lines, and leaves of the Pt-inoculated and non-inoculated Thatcher susceptible lines. Differentially expressed clones were analyzed by significance analysis of microarrays (SAM), followed by further sequencing. A total of 36 Lr39/41-resistance-related differentially expressed genes (DEGs) were identified, many of which had been previously reported to be involved in the plant defense response. The expression levels of eight selected DEGs during different stages of the Lr39/41-mediated resistance were further quantified by a qRT-PCR assay. Several pathogenesis-related (PR) and HR-related genes seem to be crucial for the Lr39/41-mediated resistance. In general, a brief profile of DEGs associated with the Lr39/41-mediated wheat resistance to Pt was drafted.     

新城疫病毒F基因重要功能区和HN基因单核苷酸多态性研究

对广泛应用的新城疫疫苗株La Sota进行了全基因组测序,并对来自9个不同基因型新城疫病毒株的血凝素神经氨酸酶(haemagglution-neuraminidase,HN)基因和融合蛋白(fusion protein,F)基因47～435 nt区域进行了用单核苷酸多态性(SNP)分析.结果表明:在F基因47～435nt间和HN基因中都存在高密度的SNP位点,Tajima's D检验结果表明这些核苷酸变化符合中性突变假说,Pi(a)/Pi(s)分析暗示F蛋白编码基因N端的一些区段和HN蛋白编码基因中散在的部分区域受到了正向选择.但F基因和HN基因在整体上却都受到了强大的负向选择压力的影响.     

早熟金针菇新品种G1的杂交选育

以金针菇菌株F3-31和FM-83为亲本,经过杂交选育出优良白色金针菇菌株G1.以菌丝生长速度、生长势、产量、子实体农艺性状及栽培周期等为指标,对金针菇菌株G1与其亲本进行比较.试验结果表明,G1菌丝生长速度快且生长势旺盛;平均单瓶产量达216 g,比亲本分别增产54 g、20 g,生物转化率也比亲本菌株高,达到72%;栽培周期43 d,比亲本分别缩短1 d、6 d;子实体各项农艺性状优良,是适于金针菇工厂化栽培的早熟白色优良菌株.     

Potential distribution of two Ambrosia species in China under projected climate change

The invasion of Ambrosia artemisiifolia and Ambrosia trifida from their native range to occupy large areas in China has raised considerable concern. Using the maximum entropy (Maxent) method, we developed models for each Ambrosia species, based on occurrence records from both native ranges (North America) and their invaded ranges (e.g. northern and south‐western Europe) to predict the availability and distribution of suitable habitats for these two species in China. For each species, we also assessed potential shifts in habitat suitability for the year 2050, using three general circulation models (GCMs) and two emission scenarios. Elevation and average mean precipitation in October contributed most to model development for both species. Potential distribution projections under future climatic change scenarios suggested an averaged percentage of suitable area (2.21%) and habitat gain (1.49%) in A. artemisiifolia distribution, with further expansion to environmentally favourable locations in south‐east coastal regions, northern Taiwan and the Beijing–Tianjin–Tangshan area in northern China. Future predicted percentage of suitable area for A. trifida was 0.03% with a very limited suitable habitat gain of <1% although this species had the potential to continue to spread in northern China. Our findings suggest that management priorities should be focused on A. artemisiifolia, whilst effective control strategies for A. trifida may be optimised by concentrating efforts on those relatively fewer regions of China where the species is currently abundant.