拮抗油菜菌核病菌的荧光假单胞杆菌的分离与筛选

2003—2005年,在上海市郊采集常见作物的根际土壤样品,经分离和纯化后共得到254个产荧光的细菌菌株。采用平板对峙培养法测定这些菌株对油菜菌核病菌的拮抗效果,结果从这254个菌株中筛选出了一个高效菌株P13。试验表明,它对菌核病菌的生长具有较强的拮抗能力,同时还发现其对多种常见的植物病原真菌具有广谱拮抗作用。通过显微观察发现,P13菌株可致使油菜菌核病菌菌丝生长形态异常,出现菌丝变形、菌丝壁溃解、原生质浓缩及外渗等异常现象,还可在一定程度上抑制菌核的形成。经电镜观察、培养物特征和一系列的生理生化实验鉴定,可初步确定P13菌株为产荧光假单胞杆菌属中的荧光假单胞杆菌。     

江苏省油菜菌核病菌对多菌灵和菌核净的抗药性监测

2006-2010年从江苏省12个地级市的油菜产区采集油菜菌核,经分离纯化共获得6017株油菜菌核病菌。采用区分剂量法测定其对多菌灵和菌核净的抗药性。结果表明,2006-2010年间江苏省各地均有多菌灵抗性菌株的分布且抗药性水平较高,抗药性频率分别为63.9%、24.0%、17.1%、16.7%和9.8%,呈逐年下降的趋势。同时经室内研究发现,多菌灵抗性菌株与敏感菌株在菌丝生长、菌核产生、以及致病力等方面无显著差异。而2006-2010年间江苏省油菜菌核病菌对菌核净表现敏感,平均抗性频率仅为0.10%,5年内只在盐城、常州、连云港三地监测到共6株低抗菌株,且菌核净低抗菌株在菌丝生长、菌核产生等方面明显弱于敏感菌株。     

土壤拮抗细菌对油菜菌核病菌的抑制作用研究

采用平板对峙培养法测定细菌CHB101对油菜菌核病菌的抑菌效果，结果表明，CHB101对菌核菌的生长具有明显抑制作用，抑菌带宽为1.12cm。显微观察发现，被抑制菌核菌菌丝壁溃解、细胞质浓缩和外渗的现象，菌丝侧面形成小型分生孢子。在WA平板上，可抑制病菌菌核萌发，随CHB101菌量提高对病菌菌核萌发的抑制作用递增，但培养滤液对菌核菌菌丝生长无明显抑制作用。     

长枝木霉T8对水稻纹枯病菌拮抗作用的研究

对峙培养表明：长枝木霉T8[Trichoderma longibrachiatum]对立枯丝核菌有较强的拮抗作用,拮抗系数为1。长枝木霉T8对立枯丝核菌形成明显的拮抗区带,界面处病菌菌丝的细胞质变稀薄、消解或菌丝断裂,病菌菌丝停止生长,同时对立枯丝核菌菌核形成包围,抑制其萌发。在光学显微镜下,可观察到长枝木霉T8对立枯丝核菌菌丝的缠绕、细胞质变稀薄、菌丝消解、菌丝断裂或侵入等现象。     

长枝木霉T8对水稻纹枯病菌拮抗的作用研究

对峙培养表明:长枝木霉T8[Trichoderma longibrachiatum]对立枯丝核菌有较强的拮抗作用,拮抗系数为1。长枝木霉T8对立枯丝核菌形成明显的拮抗区带,界面处病菌菌丝的细胞质变稀薄、消解或菌丝断裂,病菌菌丝停止生长,同时对立枯丝核菌菌核形成包围,抑制其萌发。在光学显微镜下,可观察到长枝木霉T8对立枯丝核菌菌丝的缠绕、细胞质变稀薄、菌丝消解、菌丝断裂或侵入等现象。     

几种核盘菌菌核重寄生真菌生物防治潜能的研究

将核盘菌（Sclerotinia sclerotiorum)菌核埋置于油菜土样中，从菌核内部分离到8株与菌核在土壤中存活有关的真菌。经平板和盆钵筛选试验，得到对油菜菌核病有较强生物防治潜能的黄绿木霉素（Trichoderma aureoviride)J75和绿色粘帚霉（Gliocladium virens)Y51菌株。对峙培养结果表明，两个菌株的菌落均能覆盖盘菌菌落、侵染菌核、使菌核腐烂。其非挥发性代谢产物能抑制核盘菌菌丝生长、降低平板上形成菌核的重量。把J75和Y51菌株培养物接种于自然油菜土壤中6个月后，使埋置在土壤中的菌核的校正腐烂率分别达53.13%和77.50%。研究结果还表明，供试菌株纤维素酶活力与其生物防治潜能有一定关系：纤维素酶活力越高，生物防治潜能越大。因此，可把真菌纤维素酶活力作为筛选土传植物病原菌生防菌株的一个参考指标。     

哈茨木霉TH-1对棉花枯萎病菌和黄萎病菌的拮抗机制研究

采用平板对峙法、杯碟法和显微观察法研究了哈茨木霉(Trichoderma harzianum)TH-1菌株对棉花枯萎病菌和黄萎病菌的拮抗作用及其机制.结果表明,哈茨木霉TH-1菌株与病菌对峙培养以及在培养基中加入TH-1菌株孢子悬浮液,对供试棉花枯、黄萎病菌均有较好的抑制效果;但TH-1菌株的代谢液对棉花黄萎病菌的抑制效果较差,对枯萎病菌几乎无抑制效果;显微观察发现,TH-1菌丝与枯、黄萎病菌的菌丝平行生长、产生附着胞结构附着于病菌菌丝上,或穿透病菌菌丝使病菌菌丝发生裂解.上述结果说明,哈茨木霉TH-1对供试棉花枯、黄萎病菌的拮抗机制主要是营养和空间竞争及重寄生作用.     

寒地油菜种子寄生菌核病生物学特性研究

本研究对寒地油菜种子寄生菌核病菌的部分生物学特性进行了初步的研究,从油菜种子提取菌核病菌。结果表明,菌丝在吸管和番茄培养基上生长最快,菌丝生长的最适温度为20～25℃,最适pH值为5～7。     

大白菜菌核病病原菌鉴定及其主要生物学特性

为明确大白菜菌核病病原菌的种类及其主要生物学特性,以大白菜菌核病病株上分离获得的菌株XN001为试验材料,对菌株进行致病性检测和形态学观察,并结合病原菌ITS区序列分析鉴定病原菌的种类,此外,通过改变病原菌菌丝和菌核的培养条件,研究病原菌的主要生物学特性。结果表明:大白菜菌核病病原菌与油菜菌核病相同都是核盘菌;菌株XN001在p H值4~11菌丝均可生长,p H值4时生长最快;菌丝生长最适温度为20~25℃;诱导菌核萌发的最适温度为4~10℃,菌核在4℃下处理3~5周,萌发效果最好;菌核经低温诱导后,培养温度在15~25℃,最适宜菌核萌发。可见,大白菜菌核病病原菌为核盘菌,适宜在酸性常温条件下生长,菌核的萌发需要低温诱导。     

金龟子绿僵菌对棉花枯萎病菌的拮抗作用研究

在实验室条件下,研究了虫生真菌金龟子绿僵菌(Metarhizium anisopliae)对棉花枯萎病菌尖孢镰刀菌(Fusarium oxysporium f.sp.vasinfectum)的拮抗作用及其机制。对峙培养结果表明,金龟子绿僵菌的3个供试菌株对3株枯萎病菌均有抑制作用,其中以Ma55抑制效果最好。在培养基中加入Ma55不同浓度的孢子悬浮液,当浓度为3.25×106 cfu.mL-1时,5 d后,对3株枯萎病菌菌丝生长的抑制率均超过70%。Ma55液体振荡培养20 d获得的无菌发酵液对3个枯萎病菌菌株菌丝生长的抑制率分别达到59.86%、56.99%和57.09%,对它们的分生孢子产生及分生孢子萌发也都具有显著的抑制作用。显微镜观察未发现金龟子绿僵菌与棉花枯萎病菌菌丝间有重寄生现象。上述结果显示,金龟子绿僵菌对供试棉花枯萎病菌的拮抗机制主要是营养竞争、空间竞争及抗生作用。     

水稻阶段性温敏白化转绿突变体stgra254的特征和基因定位

为了挖掘和鉴定更多的水稻白化转绿突变体用于基因功能的研究。从粳稻品种秀水09的EMS突变体库中发现了一个阶段性温敏白化转绿突变体stgra254,该突变体在28℃恒温条件下,第6片完全展开叶出现白斑,至分蘖盛期融合成片,最终叶片枯萎死亡;在32℃条件下,第6片叶白斑数目及白化程度明显弱于28℃,且3d后逐渐转绿;而24℃下的叶片表现正常。组织化学分析结果表明,白斑的形成和发展是一个程序性细胞死亡的过程,伴随着H_2O_2的积累。荧光仪分析显示,光系统Ⅱ的最大光能转化效率显著下降。遗传分析表明,该突变体叶色性状受1对隐性核基因控制。利用stgra254与珍汕97杂交得到F_2群体,借助集团分离分析法和SSR分子标记连锁分析,将其定位在4号染色体上的RM17206与RM17277标记之间,遗传距离分别为0.48,5.22cM。     

Genetics of self-compatibility in dihaploids of Solanum tuberosum L. 3. Lethality of S-bearing translocation homozygotes

Summary Self-compatible (sc) plants from an I₁ of the sc dihaploid G254 and from the reciprocal F₁'s of crosses between G254 and another sc dihaploid, B16, were crossed with the self-incompatible (si) dihaploid G609. The 34 progenies thus obtained were tested for self-compatibility. Only 2 progenies consisted merely of sc plants, the remaining ones showing a homogeneous series of 1 : 1 ratios. It is concluded that homozygosity for the S-bearing translocation mostly leads to lethality. Evidence is presented, that lethality takes place in the very early stages of the embryo and endosperm development. On the basis of the results the expected sc : si ratios in G254 × B16 and reciprocal are calculated to be 3.3 : 1. This ratio was found indeed in our experiments. These findings support the hypothesis put forward in earlier publications in this series, that self-compatibility in G254 and B16 is based on the presence of an S-bearing translocation.     

The Meaning of UV254 as an Organic Matter Monitoring Parameter in Water Supply & Wastewater Treatment

Through the discussion from a view different from the traditional, the correlations between UV 254 and organic matter monitoring parameters in the field of water supply and wastewater treatment was discussed, such as TOC, DOC and THMs precursors. According to the explanation of applicability in this paper, UV 254 can be used as a surrogate parameter. The measurement of UV 254 as a surrogate parameter has several advantages, such as inexpensive instrument, convenient operation, low operating costs, good correlations to the parameters surrogated, high accuracy and excellent data reappearance in multiple measurements. The application of UV 254 as an indirect parameter is quite valuable, especially under the current financial level of the operation and monitoring of the water and wastewater treatment plants and the laboratory research in China.     

Inheritance of genetic markers from two potato dihaploids and their respective parent cultivars

Summary In the first inbred generation (I₁) of cv. Black 4495 a dark green, slowly growing mutant (coded ds) was found, whereas the I₁ of its self-compatible dihaploid, B16, comprised this ds mutant and in addition the mutants virescens (v) and yellow margin (ym). The occurrence of ds and ym might trace back to diploid S. phureja, one of the ancestors of Black 4495. No lethal mutants were observed in I₁ of B16. Analysis of I₁ of cv. Gineke revealed a simplex condition for virescence and either duplex or triplex heterozygosity for one lethal gene. On the other hand, the I₁ of its dihaploid, G254, segregated for virescence and for three different lethal genes. It is shown that both in B16 and in G254 homozygosity of an S-bearing translocation causes early death of embryo and endosperm, thus preventing seed development. From this study it appeared that the three lethal genes from G254 affect germination rate of the seeds. The genotypes at 11 loci of B16 and G254 are presented.Visiting scientists from Birmingham, England and Mlochow, Poland, respectively.     

NaCl胁迫对6种纤维亚麻幼苗生化特性的影响

旨在为筛选、培育耐盐的纤维亚麻突变体奠定前期基础。NaCl胁迫亚麻幼苗,测定幼苗的叶绿素组成及含量、脯氨酸、可溶性糖、可溶性蛋白和甜菜碱含量,经统计学分析和比较,确定它们的耐盐特性。结果表明,经250 mmol/L NaCl胁迫后,HIZ019和‘天鑫3号’幼苗的脯氨酸含量显著高于其他品种;YOI303和YOI254幼苗的可溶性糖含量显著高于其他品种;YOI254幼苗的可溶性蛋白含量显著高于其他品种;HIZ019、‘天鑫3号’幼苗的甜菜碱含量显著高于其他品种。总体上看,YOI254、‘天鑫3号’和HIZ019纤维亚麻幼苗耐盐性较好。     

石灰混凝+吹脱+CO2曝气联合对垃圾渗滤液的处理实验研究

为了有效降低垃圾渗滤液中高浓度的氨氮和有机污染物,以便降低后期生化处理的污染负荷,采用石灰混凝+吹脱+CO2曝气联合法对垃圾渗滤液进行预处理,通过单因素实验研究CaO投加量、曝气时间、反应温度及气液比等因素对渗滤液中氨氮、COD以及UV254的去除效果的影响;通过正交实验研究综合处理效果最好的反应条件,并在正交实验后进行CO2曝气,以期降低实验后较高的pH和钙离子浓度。结果表明：氨氮去除率与各单因素呈正相关关系,COD及UV254的去除率与CaO投加量相关性较大。在正交试验得出的最佳混凝吹脱条件下,氨氮、COD、UV254的去除率分别能达到98.8%、60.2%、68.7%。进一步CO2曝气后,垃圾渗滤液pH由12.1降至6.8,钙离子浓度降低70.3%,COD去除率可达65.7%。     

黄河流域棉花主要品种SSR指纹图谱构建及遗传差异分析

 利用SSR分子标记构建了2009－2010年黄河流域23个主要棉花品种和2010年山东省区试4个品系的分子指纹图谱并进行遗传多样性分析。63对引物在27份供试材料中共扩增到多态性条带254条,平均每对引物4.03条。22对引物在23个品种（系）上具有特征谱带,除鲁棉研21号、鲁棉研36号、鲁436、邯棉559外,均可用1对引物进行鉴定;采用引物组合法只需要5对引物就能将27份供试材料区分开,并利用这5对引物构建了上述品种（系）的数字指纹图谱。遗传多样性分析显示,27个品种（系）间遗传相似系数介于0.5394~0.9685之间,平均为0.6878,并且同一省份所选育的品种（系）大都聚到同一类群,说明黄河流域选育的品种还存在一定的地域局限性。     

高速逆流色谱法分离澳洲薄荷中香叶木苷

为研究澳洲薄荷中香叶木苷的高效制备问题,以澳洲薄荷为原料,建立高速逆流色谱仪分离澳洲薄荷中香叶木苷的方法。澳洲薄荷干燥茎叶用65%乙醇提取,经AB-8 型大孔吸附树脂初步纯化后得到澳洲薄荷总黄酮提取物,然后采用乙酸乙酯-正丁醇-水-乙酸(3:1:3:0.005,V/V)的两相溶剂体系进行香叶木苷单体的高速逆流分离纯化：上相为固定相,下相为流动相,主机转速1600 r/min,流动相流速0.8 mL/min,柱温25℃,检测波长254 nm。分离得到的香叶木苷经液相色谱检测纯度达95.2%。     

Molecular adaptation of barley to cold and drought conditions

Summary Molecular adaptation to cold and drought involves a series of biochemical and molecular changes leading plants to improve their winter hardiness or drought resistance.We are interested to study the molecular basis of cold acclimation and drought response of barley to survive under stress. Several genes regulated by low temperatures and sometimes by drought have been isolated from the barley genome. In this review the most significant results of our recent work will be presented and discussed.The protein encoded by cDNA clone pt59 and induced in barley by cold was over-expressed in E. coli to produce the matching antibody, which in vivo recognizes a cold-induced protein of 14 kDa (COR14). The COR14 is stored in amounts only slightly greater in the cold resistant Onice than in the susceptible Gitane, although the former has a higher induction-temperature threshold of COR14 than the latter. This fact is an evolutionary advantage enabling the resistant varieties in the field to prepare for the cold well ahead of the susceptible ones.Two other cDNA clones, paf93 and cdr29, are regulated by low temperature and drought stress but not by exogenous ABA treatment. Indeed during the early stage of dehydration, the mRNAs are expressed before the induction of known ABA regulated genes such as dehydrins and when only a small increase occurs in ABA content. The sequence analysis revealed that paf93 encodes for a protein homologous to the cold-regulated protein COR47 of Arabidopsis, whereas cdr29 represents a plant gene homologous to yeast and mammalian sequences coding for acyl-Coenzyme A oxidase.Abbreviations ABA abscisic acid - COR cold regulated