光质对紫背天葵生长、次生代谢和抗氧化胁迫的影响

以紫背天葵为供试材料,采用LED灯精量调控光质和光强,研究相同光照强度(350±5 μmol·m^-2·s^-1)下,白光(W)、红光(R)、蓝光(B)、黄光(Y)、红蓝混合光(RB)、红蓝黄混合光(RBY)对紫背天葵生长、次生代谢和氧化胁迫抗性的影响.结果表明:与白光(W)相比,红光(R)能够显著促进紫背天葵植株的生长以及干物质和可溶性糖含量的积累;而蓝光(B)则抑制紫背天葵的生长;叶绿素含量在有色光处理下均显著降低;虽然红蓝黄混合光(RBY)未能显著提升紫背天葵的干物质含量,但总酚、类黄酮和花青素含量显著提升,这些还原态物质的积累有利于提高紫背天葵的抗氧化能力,在增强自身抗逆性的同时提升营养价值.本研究为光质调控紫背天葵的多样化生产提供了理论依据.     

玉米全生育期黄化材料的光合性能分析

通过对玉米(Zea mays L.)黄化材料和2份正常自交系的光合特性、光响应曲线及荧光动力学参数进行分析,结果表明,黄化材料yglm1的净光合速率(Pn)、气孔导度(Gs)和胞间CO2浓度(Ci)均显著低于正常自交系Mo17和RP128,而蒸腾速率(Tr)却显著高于正常自交系;黄化材料的光补偿点、光饱和点、暗呼吸速率及表观量子效率均高于正常自交系Mo17和RP128,但其净光合速率却低于正常自交系;黄化材料的荧光动力学参数初始荧光(Fo)、最大荧光(Fm)、PSⅡ原初光能转换效率(Fv/Fm)、PSⅡ原初光能捕获效率(Fv'/Fm')、PSⅡ光下实际光化学效率(ΦPSⅡ)、光化学猝灭系数(qP)均显著低于正常自交系Mo17和RP128,非光化学猝灭系数(qN)显著高于正常自交系。相对于正常自交系,黄化材料具有较低的电子传递潜力、原初光能捕获效率和转换效率、光能分配及利用率,这可能是导致其净光合能力降低的根本原因。     

D,L-甘油醛处理引起的小麦叶片表观光合量子效率的降低（英文）

D,L-甘油醛(磷酸核酮糖激酶抑制剂,10mmol/L)处理小麦旗叶1 h可降低叶片净光合速率和表观量子效率.同时,光系统Ⅱ光化学效率(△F/Fm′)、电子传递速率(ETR)和单位叶面积ATP含量均降低,而胞间二氧化碳浓度(Ci)和叶绿素荧光非光化学猝灭(NPQ)增加.这些结果说明,D,L-甘油醛引起的小麦旗叶表观量子效率降低是由于光合碳同化受阻对光合电子传递的反馈抑制.     

D，L—甘油醛处理引起的小麦叶片表观光合量子效率的降低

D,L－甘油醛（磷酸核酮糖激酶抑制剂,10mmol/L)处理小麦旗叶1h可降低叶片净光合速率和表观量子效率。同时,光系统Ⅱ光化学效率（ΔF/Fm′）,电子传递速率（ETR）和单位叶面积ATP含量均降低,而胞间二氧化碳浓度（Ci)和叶绿素荧光非光化学猝灭（NPQ）增加,这些结果说明,D,L－甘油醛引起的小麦旗叶表观量子效率降低是由于光合碳同化受阻对光合电子传递的反馈抑制。     

紫背天葵叶片中花青素种类及合成调控基因转录组分析

为获取紫背天葵(Cynura bicolor DC.)叶片中花青素种类及其合成调控基因等信息,该试验以紫背天葵叶背面紫色以及经处理叶背面几乎全绿(对照)的叶片为材料,进行转录组测序分析,同时进行6个相关差异表达基因的qRT-PCR分析和6种花青素苷元的HPLC检测,以揭示紫背天葵特有的花青素苷元及其合成调控关键基因信息。结果表明:(1)在紫背天葵中共获得14个花青素苷元及32个花青素合成调控基因信息,其中表达量差异显著下调的4个基因为Pg(c11692)、Cy(c42112)、ANS(c38551)和3GT(c9064),表达量差异显著上调的2个基因是D FR(c35961)和3GT(c20283)。(2)qRT-PCR检测结果显示,上述6个基因在2种紫背天葵叶中的表达趋势(上调或下调)与转录组测序结果完全一致,但转录组测序检测到的表达趋势差异倍数比qRT-PCR检测结果更加明显。(3)HPLC分析显示,紫背天葵叶中均未检测到Dp、Pt、Pn及Mv等4类花青素苷元,但紫背天葵叶中富含Cy花青素苷元,且背面紫色的叶中Cy类花青素苷元含量(62.21 mg/kg)显著高于绿色叶对照(6.86 mg/kg);背面紫色和全绿叶中的Pg花青素苷元含量均低于0.43 mg/kg。研究推测,Cy和Pg花青素苷元在绿叶紫背天葵(对照)中含量显著降低可能是因为存在1个ANS和1个3GT正调控以及1个DFR和1个3GT负调控所致。     

影响紫背天葵试管苗花青甙含量的因素Ⅱ

本文叙述激素、光、培养温度和时间对紫背天葵试管苗花青甙含量的影响。NAA在0.125—1.0毫克/升范围内能增加花青甙含量,以0.125毫克/升效果最好,BA、2ip、ZT降低花青甙含量。光能明显地提高紫背天葵的花青甙含量,在试验范围内,花青甙含量随光照强度的增加而增加;比较了蓝、白、红三种单色光单独及结合照射的作用,对提高花青甙含量表现为蓝光>红光>白光,红、蓝两色光结合一起照射时比它们单独使用的效果更好,对促进生长的作用则是白光>红光>蓝光;单色光对花青甙含量的影响与照射的顺序无明显的关系。培养温度为25℃时,在90天内对紫背天葵的生长及花青甙含量的提高都有利。在试验条件下,培养95天左右的时间是适宜的采收期。     

不同氮素形态对向日葵生长和光合功能的影响

利用砂培试验研究了不同氮素形态对向日葵生长和光合功能的影响。结果表明：NO^3-N(NN)处理的株高、叶面积、干物质重显著高于NH4^ -N(AA)处理,施用NO3^--N的植株有较高的净光合速率(Pn)和较低的气孔导度(C8)、细胞间隙CO2浓度(Ci)。不同处理之间Fv／Fm没有显著差异,NN处理的植株PSⅡ线性电子传递量子效率ФPSⅡ、光化学荧光猝灭系数qP和表观光合电子传递效率ETR都显著高于AA处理的植株;而非光化学荧光猝灭系数qN则明显低于AA处理的植株。碳同化受到抑制是NH4^ -N条件下净光合速率下降的重要原因。     

紫背天葵(Begonia fimbristipula Hance)回归植株存活及叶片生物学特性研究

紫背天葵(Begonia fimbristipula Hance)是中国特有的珍稀濒危植物, 采用原位和异位土壤、异地和增强回归处理, 研究了紫背天葵回归的存活情况及其叶片的生态生物学特性。结果表明: 增强回归因受啮齿类哺乳动物的取食而失败; 异地回归取得成功, 异位土壤和原位土壤上回归植株的成活率分别为46.7%和83.3%。原位和异位土壤这两种异地回归植株与野生植株相比, 在叶片的形态、解剖及生理特征上都表现出一定的差异性, 其光适应能力减弱、抗寒旱能力降低、光合能力降低、光合产物积累减少; 异位土壤回归的植株比原位土壤回归的植株相比更差。异地回归紫背天葵叶片花青素含量较低, 仅为野生植株含量(2.33μmol·g^–1)的16.95%。异地回归植株所表现出的上述特征可能受回归点与原生境不同微生境(气候和土壤)的影响, 也可能是与组培球茎与野生球茎在表现遗传学上有所差异有关。在开展紫背天葵野外回归实践时, 要充分考虑回归地点的微生境、捕食者和病菌对紫背天葵存活的影响、以及药用有效成分的含量。     

紫背天葵中营养成分及总黄酮分析

对食、药两用植物紫背天葵营养成分和总黄酮进行了研究 ,结果显示紫背天葵各种营养成分齐全且丰富 ,其中总氨基酸质量分数达 1 3.0 3% ,必需氨基酸占总氨基酸的 4 4 .1 3%。含人体必需的无机元素 1 2种 ,人体必需的微量元素 7种。植物中正丁醇提取部位的总黄酮含量为 0 .4 1 %。这些研究为人们认识紫背天葵的营养和药用价值 ,充分开发利用祖国的植物资源提供参考     

γ-氨基丁酸(GABA)对低氧胁迫下甜瓜幼苗光合作用和叶绿素荧光参数的影响

采用营养液水培方法,研究了低氧胁迫下外源γ-氨基丁酸(GABA)对甜瓜幼苗光合色素含量、光合作用及叶绿素荧光参数的影响.结果表明:低氧胁迫导致甜瓜幼苗光合色素含量显著下降,光合作用降低;外源GABA能显著提高正常通气和低氧胁迫下甜瓜幼苗的光合色素含量、净光合速率、气孔导度、胞间CO2浓度、CO2羧化效率、最大光化学效率、光化学猝灭系数、表观光合电子传递速率和PSⅡ光合电子传递量子效率,而气孔限制值、初始荧光和非光化学猝灭系数显著降低,GABA在低氧胁迫下的提高效果更明显;同时添加GABA和GABA转氨酶抑制剂γ-乙烯基-γ-氨基丁酸(VGB)处理显著降低了低氧胁迫下GABA对甜瓜幼苗光合特性的缓解效果.     

Evolutionary relationships among aquatic anamorphs and teleomorphs: Lemonniera, Margaritispora, and Goniopila

The hypothesis that similar conidial morphologies in aquatic hyphomycetes are a result of convergent evolution was tested using molecular sequence data. Cladistic analyses were performed on partial sequences of 28S rDNA of seven species of Lemonniera, one species of Margaritispora and one species of Goniopila. Lemonniera has tetraradiate conidia with long arms, whereas Margaritispora and Goniopila have typically globose (isodiametric) conidia, with short conical protuberances in a stellate or quadrangular arrangement. Lemonniera and Margaritispora have phialidic conidiogenesis and both produce dark, minute sclerotia in culture whereas Goniopila has holoblastic conidiogenesis and does not produce sclerotia in culture. Goniopila produces a microconidial phialidic synanamorph in culture. All three genera have schizolytic conidial secession. Molecular analyses demonstrate that Lemonniera species are placed in two distinct clades: one within Leotiomycetes; the other within Pleosporales, Dothideomycetes. Margaritispora is placed with Lemonniera species within Leotiomycetes. Goniopila and Lemonniera pseudofloscula are placed within Dothideomycetes. No morphological character was entirely congruent with the molecular derived phylogeny. This suggests that for the group of species studied, conidial shape is not a reliable indicator of phylogeny but more likely the result of convergent evolution in response to the aquatic environment.     

甘菊ClHSP70与ClHSP90基因的克隆及表达分析

该研究以甘菊(Chrysanthemum lavandulifolium)为实验材料,通过RT-PCR方法从甘菊转录组数据中分离出热激蛋白合成相关基因,命名为ClHSP70和ClHSP90。序列分析表明,ClHSP70基因ORF全长为2 559bp,编码852个氨基酸,蛋白功能区预测表明含有典型的HSP70蛋白NBD和SBD保守结构域;ClHSP90基因ORF全长为2 094bp,编码697个氨基酸,含有HATPase结构域和HSP90保守结构域。生物信息学分析表明,甘菊ClHSP70与大豆(Glycine max)和烟草(Nicotiana tomentosiformis)HSP70蛋白有较高的一致性,ClHSP90基因编码的氨基酸序列与紫茎泽兰(Ageratina adenophora)HSP90高度相似;实时荧光定量表达分析表明,在42℃处理不同时间,甘菊叶片中ClHSP70和ClHSP90基因表达均在0.5h时显著增加,1h达到最大值,2h后缓慢下降;不同组织表达分析表明,甘菊在42℃处理1h后,ClHSP70在成熟叶中的表达量显著高于嫩叶和根等其他组织;ClHSP90在成熟茎中的表达量最高。研究说明,ClHSP70和ClHSP90基因具有热激蛋白特征,参与了甘菊热胁迫应答过程,该研究结果为以后深入研究其基因功能奠定了基础。     

基因CfATG6和CfATG14参与调控果生刺盘孢细胞自噬和致病力

【目的】炭疽病是油茶的主要病害,由刺盘孢属的多种真菌引起,其中果生刺盘孢分布范围最广、分离率最高,是油茶炭疽病的主要致病菌。研究自噬相关蛋白CfAtg6和CfAtg14的生物学功能,为进一步揭示果生刺盘孢通过细胞自噬调控致病的分子机制,并为油茶炭疽病的防治提供理论基础。【方法】根据同源重组原理,通过聚乙二醇(polyethylene glycol, PEG)介导的方法,在果生刺盘孢中敲除基因CfATG6和CfATG14,并进一步获得回补菌株ΔCfatg6-C和ΔCfatg14-C。【结果】酵母双杂交试验结果显示,果生刺盘孢蛋白CfAtg6和CfAtg14可能存在互作关系。生物学表型测定结果表明,相较于野生型和回补菌株,突变体ΔCfatg6和ΔCfatg14均表现出营养生长速率显著减慢,附着胞形成率分别只有野生型的5%和18%;突变体ΔCfatg6和ΔCfatg14致病力均极显著减弱,造成的油茶叶片病斑面积少于野生型和回补菌株的1/3;CfATG6和CfATG14基因缺失突变体均丧失转运和降解CfAtg8蛋白的能力,并对细胞壁胁迫更敏感。突变体ΔCfatg6的分生孢子产量显著降低,仅为野生型的20%左右;氧化胁迫试验结果表明,相较于野生型和回补菌株,过氧化氢对突变体的生长抑制率升高10%左右。内质网压力胁迫试验表明,ΔCfatg14对二硫苏糖醇抑制率升高5%以上。【结论】自噬相关基因CfATG6和CfATG14参与调控了果生刺盘孢生长发育、细胞自噬和致病力。     

下延叉蕨和芽胞叉蕨配子体发育的研究

利用光学显微镜详细观察了叉蕨属(Tectaria)下延叉蕨(Tectaria decurrens)和芽胞叉蕨(T.fauriei)的配子体发育过程,记录了配子体各发育阶段的特征。结果表明:(1)下延叉蕨和芽胞叉蕨的孢子均为单裂缝,具周壁,由周壁形成纹饰,孢子极面观椭圆形,赤道面观豆形或肾形。(2)孢子萌发方式为向心型。(3)原叶体发育方式为三叉蕨型。(4)成熟原叶体心脏形,两翼向斜上方扩展。(5)均具单细胞和多细胞毛状体,在丝状体或片状体阶段出现。研究认为,从配子体发育角度看,叉蕨属是较进化的陆生真蕨类;毛状体的类型、位置和出现时间等特征在叉蕨属种间存在差异,可作为该属种间分类的特征。     

The phylogenetic placement of the Leucogastrales, including Mycolevis siccigleba (Cribbeaceae), in the Albatrellaceae using morphological and molecular data

The morphology of many hypogeous fungi converges on a homogeneous reduced form, suggesting that disparate lineages are subject to a uniform selection pressure. The primary goal of this study was to evaluate the morphology and infer the phylogeny of the Leucogastrales with Mycolevis siccigleba using a Bayesian methodology. A comprehensive morphological assessment was used for an a priori phylogenetic inference to guide the sequencing effort. All structures except spore ornamentation pointed to the Albatrellaceae as the most likely sister taxon. Polyporoletus sublividus, a close relative of Albatrellus, produces ornamented basidiospores with a similar structure to M. siccigleba basidiospores. The ITS from 30 taxa was used for the molecular phylogenetic analysis. P. sublividus was found sister to Mycolevis. Leucophleps spinispora and L. magnata formed a group sister to the Polyporoletus/Mycolevis group, whereas Leucogaster was polyphyletic with respect to the core of the Leucogastrales and sister to A. caeruleoporus. This relationship was expected as previously undescribed chlamydospores produced by members of Albatrellus had a similar morphology to the basidiospores of L. rubescens.     

Molecular and morphological characterization of Leveillula (Ascomycota: Erysiphales) on monocotyledonous plants

Leveillula on monocotyledonous plants have been recorded as L. taurica by several authors, whereas the fungus on Allium has been described as an independent species, namely L. allii, by some authors. We sequenced ca 600 bp of the rDNA ITS region for two Leveillula specimens from Allium and Polianthes (both from monocotyledons) and compared them with several already published sequences from Leveillula isolates from dicotyledons. Pair-wise percentages of sequence divergences were calculated for all Leveillula isolates. The ITS sequence of the Polianthes isolate was identical to L. taurica on Helianthus and Vicia. The sequence of the Allium isolate was 99.5 % identical to L. taurica on Euphorbia, Haplophylum, Peganum, etc. These results suggest close relationships between monocot and dicot pathogenic Leveillula species. The identity between two monocot isolates was 98.4 %. Phylogenetic analysis revealed that the two monocot isolates do not group into a clade together. This result suggests that Leveillula acquired parasitism to monocots at least twice independently.     

Genome Analysis inNeurospora crassa;Cloning of Four Lociarginine-1(arg-1),methionine-6(met-6),unknown-7(un-7), andribosome production-1(rip-1) and Associated Chromosome Walking

We have cloned fourNeurospora crassagenes by complementation analysis. Cloned genes include thearginine-1(arg-1),methionine-6(met-6),unknown-7(un-7), andribosome production-1(rip-1) loci. Chromosome walks were initiated in ordered cosmid libraries from the cloned loci. A total of about 700 kb of theNeurosporagenome is covered in these walks.     

Evaluation of Beauveria bassiana and B. brongniartii strains and four wild-type fungal species against adults of Bactrocera oleae and Ceratitis capitata

The virulence of two isolates of the hyphomycete fungi, Beauveria bassianaand B. brongniartii, and additional fungal species isolated from diseased Bactrocera oleae pupae and Sesamia nonagrioideslarvae were assessed against adults of the olive fruit fly B. oleae and the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae). Contact and oral bioassays revealed that moderate to high mortality rates for the olive fruit fly occurred when the adults were exposed to conidia of Mucor hiemalis, Penicillium aurantiogriseum, P. chrysogenum and B. bassianaisolates. A strain of M. hiemalis isolated from S. nonagrioides larvae was the most toxic resulting in 85.2% mortality to the olive fruit fly adults. B. brongniartiiand B. bassiana were the most pathogenic to the C. capitataadults causing 97.4 and 85.6% mortality. Metabolites collected from the M. hiemalis and P. chrysogenum isolates were toxic to adults of both species.