The endophytic fungus Piriformospora indica protects wheat from fusarium crown rot disease in simulated UK autumn conditions

The root endophytic fungus Piriformospora indica (Sebacinacea) forms mutualistic symbioses with a broad range of host plants, increasing their biomass production and resistance to fungal pathogens. This study evaluated the effect of P. indica on fusarium crown rot disease of wheat, under in vitro and glasshouse conditions. Interaction of P. indica and Fusarium isolates under axenic culture conditions indicated no direct antagonistic activity of P. indica against Fusarium isolates. Seedlings of wheat were inoculated with P. indica and pathogenic Fusarium culmorum or F. graminearum and grown in sterilized soil‐free medium or in a non‐sterilized mix of soil and sand. Fusarium alone reduced emergence and led to visible browning and reduced root growth. Roots of seedlings in pots inoculated with both Fusarium isolates and P. indica were free of visible symptoms; seed emergence and root biomass were equivalent to the uninoculated. DNA was quantified by real‐time polymerase chain reaction (qPCR). The ratio of FusariumDNA to wheat DNA rose rapidly in the plants inoculated with Fusarium alone; isolates and species were not significantly different. Piriformospora indica inoculation reduced the ratio of Fusarium to host DNA in the root systems. The reduction increased with time. The ratio of P. indica to wheat DNA initially rose but then declined in root systems without Fusarium. With Fusarium, the ratio rose throughout the experiment. The absolute amount of FusariumDNA in root systems increased in the absence of P. indica but was static in plants co‐inoculated with P. indica.     

磁小体研究进展

趋磁细菌（magnetotactic bacteria, MTB）能够在细胞内合成由生物膜包裹的纳米级磁铁矿粒子-磁小体(magetosome)。磁小体的合成过程尤其是铁离子的反应途径及吸收转运受到严格的生物调控。磁小体完美的晶体结构使其在医学成像、磁介导热疗、药物输送等众多领域都有良好的应用价值。主要对磁小体矿化过程中铁的反应途径和吸收转运系统做一综述,并介绍了磁小体在上述等方面的应用,对未来的研究方向做了展望。     

福建省蛋鸡血管瘤型J亚群白血病的分子生物学诊断

针对福建省某鸡场的蛋鸡群发生产蛋下降和部分死亡,病鸡脚趾明显呈现血管瘤特征,运用实时荧光定量PCR方法对病鸡组织和血液样品进行检测,检出了J亚群白血病病毒(ALV-J);通过基因序列的比较分析,发现其氨基酸序列与国外及国内其他省份报导的ALV-J有很高的同源性,从病原分子生物学诊断角度证实福建省蛋鸡群中ALV-J的存在。     

台湾杉ISSR反应体系的建立及检测

在保持1U Taq酶和0.2 mmol/L dNTP两个条件不变的情况下,通过对模板DNA的浓度、引物浓度与Mg2+浓度的筛选,建立了台湾杉的优化ISSR反应体系,即在25 μ1的反应体系中,含有40 ng模板DNA、1 UTaq酶、0.2 mmol/L dNTP、0.4μmol/L引物、1.8 mmol/L Mg2+、2.5 μL 10×buffer.扩增程序为:94℃,4 min; 94℃,45s,51～56℃,45s,72℃,2 min,40个循环;72℃,7 min.利用这种优化的反应体系,筛选出了10条稳定性强、清晰度高并表现出一定多态性的ISSR引物,并进一步筛选出了这10条引物的最佳退火温度.应用这些引物对分布于湖北利川市星斗山保护区的台湾杉野生居群的20个样品进行了扩增,结果表明,利川星斗山台湾杉居群的多态位点百分率为61.97％,Nei's基因多样性和Shannon's信息指数分别为0.136 9和0.216 0.     

大花萱草ISSR-PCR最佳反应体系的建立

ISSR标记能揭示出种间、种内遗传变异情况,更好地揭示亲缘关系和遗传多样性。以大花萱草的5个品种为试材,研究了影响大花萱草ISSR-PCR扩增效果的各项因素,建立了适合大花萱草ISSR-PCR的最佳反应体系:20μL反应体系中,10×buffer 2μL,dNTP 0.2 mmol/L,Mg2+浓度1.5 mmol/L,引物浓度0.5 mmol/L,Taq酶10.002 nkat,DNA模板20 ng。大花萱草的最佳ISSR扩增反应程序为:94℃预变性5 min;94℃变性40 s,50℃退火45 s,72℃延伸1.5 min,共40个循环;最后72℃延伸10 min。通过该反应程序进行的大花萱草ISSR扩增可获得清晰、稳定的条带。     

酸雨与稀土镧对大豆幼苗光合光反应复合影响的时间效应研究

采用水培法研究酸雨(AR)与稀土镧(La)对大豆幼苗叶片光合光反应复合影响的时间效应,旨在探究复合污染因子对植物自修复过程的影响。结果表明,较之不同pH值AR(pH3.0、4.0)和不同剂量La(60、300mg·L-1)的单一作用,复合处理对大豆幼苗光合光反应活性抑制程度较大,延缓各参数恢复进程(恢复拐点滞后),恢复程度较小,明显影响了植物的自修复能力。净光合速率Pn与各光合参数相关性分析结果显示:复合处理组的植物在修复过程中,Pn变化主要受Chl、Hill反应活性的影响,Mg2+-ATPase活性对Pn的制约最小,且随着时间的推移,AR与La复合处理组各光合参数的恢复进程不同步,自修复能力受胁迫强度和胁迫方式的影响。     

Role of exogenous phytohormones on growth and plumbagin accumulation in Plumbago indica hairy roots and conservation of elite root clones via synthetic seeds

The present study describes the role of different exogenous hormones on morphology and plumbagin production in Plumbago indica hairy roots. It was also aimed to conserve elite root clones via synthetic seed technology. Insertion of rolB gene in transformed roots was confirmed by polymerase chain reaction followed by southern blot analysis. Hairy roots were treated with single or in combination of different phytohormones viz. IAA, IBA, 2, 4-D, NAA, BAP, GA₃ and ABA. Cultures incubated with GA₃ (0.5 mg l⁻¹) yielded highest root growth due to formation of profuse lateral branching while NAA (0.5 mg l⁻¹) treatment caused highest plumbagin accumulation. Cultures incubated with 2, 4-D exhibited highest inhibitory effect in terms of both root growth and plumbagin production. All phytohormones were found to be effective at lower concentration. In combinatorial study, GA₃ + NAA (0.5 mg l⁻¹, each) was found optimum for root biomass and plumbagin production at earlier stage of culture. Different combinations of auxins and BAP induced different morphologies ranging from reduction of lateral branching to rapid disorganization of root matrix. The combinations of ABA and selected auxins were not found promising at any of selected concentration. Based on the effect of exogenous hormones on hairy root culture, elite root clones were selected and encapsulated with sodium alginate matrix. Uniform shaped alginate coated synthetic seeds were conserved up to 6 months exhibited high regeneration potential without disturbing plumbagin content.     

水稻多酚氧化酶基因功能标记的开发与应用

 水稻酚反应是水稻分类的重要依据。控制水稻酚反应的多酚氧化酶基因(PPO)已经克隆,根据其等位基因的DNA序列差异设计了InDel功能标记FMppo 18和FMppo 29。利用这两个标记对45份材料进行了标记基因型分析和酚反应鉴定。结果发现3份普通野生稻为非缺失带型;8份籼稻材料中6份为非缺失带型,而Dular为缺失29 bp带型,龙晴为缺失18 bp带型,表明Dular和龙晴分别携带29 bp和18 bp缺失的PPO等位基因;11份粳稻材料中9份携带18 bp缺失的PPO等位基因,2份携带29 bp缺失的PPO等位基因。对23份杂草稻鉴定的结果表明,7份早年发现的杂草稻,即3份江苏省连云港穞稻和4份安徽省怀远、来安、全椒、肥东的塘稻为非缺失带型;而16份近年来发现的杂草稻中14份不缺失,2份表现为18 bp缺失的PPO等位基因,与江苏省大面积推广的栽培粳稻品种携带相同的PPO基因。酚反应结果表明带29 bp或18 bp缺失的PPO等位基因的材料酚反应呈阴性,而不缺失的材料酚反应呈阳性。标记基因型与酚反应表现型完全对应。表明这两个功能标记可用于水稻种质资源鉴定、进化研究以及多酚氧化酶基因的分子标记辅助选择育种。     

3种木质素降解菌的筛选及对构树降解的研究

[目的]筛选高效降解木质素的菌种。[方法]通过马铃薯琼脂平板培养、马铃薯液体摇瓶培养和变色反应,对采自吉文山枯木中的木质素降解菌进行了筛选,并对其降解构树的卡伯值和纤维素进行了测定。[结果]共筛选出3种对木质素降解能力较强的菌种,分别为JWS-1、JWS-2和向日葵菌核病菌。[结论]为进一步研究生物制浆奠定了基础。     

过氧化氢法制备二氧化氯反应残液的综合利用研究

[目的]研究过氧化氢法制备二氧化氯反应残液的综合利用,为工艺的进一步优化和产业化推广提供理论依据。[方法]将反应残液进行浓缩结晶,回用酸溶液,获副产品NaHSO4.H2O,考察浓缩蒸发量、结晶温度等对残液浓缩结晶的影响及残液循环对二氧化氯制备主要技术参数的影响。[结果]反应残液循环利用最佳浓缩蒸发量为55%～60%,最佳结晶温度为40～44℃,残液结晶循环综合利用对二氧化氯产品纯度和原料转化率无不利影响。[结论]该方法实现了废液的零排放和酸使用量的最小化,产生较好的经济效益和环境效益。