温度与光强对高山杜鹃催花期间花芽营养物质积累的影响

以高山杜鹃为材料,研究了在3个昼/夜温度(6℃/0℃、22℃/16℃、30℃/24℃)和3个光照强度(2 000/10lx、7 500/5 500lx、10 000/8 000lx)组合成的9个光温催花条件下,高山杜鹃花芽内可溶性糖、淀粉、可溶性蛋白和游离氨基酸等营养物质的变化以及对始花期的影响。结果表明:随着昼夜温度的升高和光照强度的加强,高山杜鹃花芽内的可溶性糖和淀粉含量增加,且在整个催花过程中持续上升;可溶性蛋白含量变化整体呈先升后降的趋势,前期随温度光强增加而增加,后期则相反;游离氨基酸含量的整体变化趋势与可溶性蛋白含量相反,表现为先降后升。在30℃/24℃、10 000/8 000lx的处理下,高山杜鹃最早进入始花期,比目标日期(春节)提前18d开花。可见,适当高温和高光强(22℃/16℃~30℃/24℃,7 500/5 500~10 000/8 000lx)处理能显著提高高山杜鹃花芽内可溶性糖、淀粉、可溶性蛋白和游离氨基酸等营养物质的积累和代谢,促进了其花芽发育,有效缩短了催花时间,使植株提前进入始花期,从而达到提前上市的目的。     

台湾独蒜兰假鳞茎显微及超微结构观察

以休眠期的台湾独蒜兰(Pleione formosana)假鳞茎为试材,利用石蜡切片及透射电子显微镜,分别对假鳞茎的5个部位(假鳞茎基部、假鳞茎中部、假鳞茎外侧、假鳞茎与叶芽相接处、假鳞茎与花芽相接处)进行了系统观察分析。结果发现：(1)台湾独蒜兰假鳞茎5个部位均观察到液泡及不同程度液泡化的细胞,表皮细胞覆着有厚厚的蜡质层。(2)台湾独蒜兰假鳞茎基部、中部、外侧细胞中均存在一定的叶绿体,少量线粒体分布在其周围。(3)假鳞茎薄壁细胞中存在淀粉粒及造粉体,且造粉体伴随有形成淀粉粒的现象。(4)假鳞茎基部、中部、外侧及其与花芽相接处的薄壁细胞壁之间有大量胞间连丝,筛管-伴胞复合体与薄壁细胞间也存在胞间连丝,同时细胞间存在不同形状的细胞间隙。研究结果表明,台湾独蒜兰假鳞茎发挥了其作为储水器官、光合作用场所及储存碳水化合物的功能,同时休眠期间主要以共质体途径进行物质的交换与运输。     

兰科奇葩——独蒜兰

福建省武夷山自然保护区以其绮丽的森林自然景观和丰富多样的生物资源而闻名于世。在那崇山峻岭的悬崖峭壁上,生长着兰科奇葩——独蒜兰(见封三照片)。 独蒜兰(Pleionebulbocodioldes),又名一叶兰,兰科独蒜兰属植物。该属10种,我国约有6种,分布于长江流域及以南各省区。独蒜兰为附生兰,株高10—25厘米,假鳞茎紫     

水仙芽可溶性糖含量及NtTIM基因的表达分析

以3年生水仙(Narcissus tazetta var.chinensis)鳞茎主芽为材料,采用蒽酮-硫酸法测定可溶性糖含量;采用PCR法从主芽中分离克隆NtTIM基因并对其序列进行生物信息学分析;采用qRT-PCR方法分析主芽不同生长发育时期和温度诱导下的表达变化。可溶性糖含量测定结果表明,水仙鳞茎膨大期,主芽可溶性糖含量逐渐降低;休眠期先升高后降低;花芽分化期其含量在均衡的水平(4%左右)。生物信息学分析表明:分离克隆到了1个NtTIM基因,该基因含有765 bp开放阅读框,编码254个氨基酸,属于TIM-phosphatebinding基因家族,推导的氨基酸序列与油菜、芜菁、拟南芥、甘蓝等植物具有85%以上的同源性;编码的蛋白为稳定的呈酸性的疏水蛋白,无信号肽位点但含有1个跨膜结构域、2个N-糖基化位点。qRT-PCR分析表明,水仙生长发育过程中鳞茎膨大期主芽NtTIM基因表达量略升高;休眠期表达量呈阶段性降低;花芽分化期表达量略升高;20℃、25℃、30℃、35℃温度处理时,主芽NtTIM基因表达量随着温度升高而降低,且处理时间越长,其表达量越低。推测NtTIM基因参与调控水仙鳞茎主芽休眠。为进一步研究NtTIM基因的分子功能,以及深入研究水仙夏休眠的分子机制提供帮助。     

低温弱光下辣椒3种渗透调节物质含量变化及其与品种耐性的关系

以12个耐低温弱光的辣椒品种为试验材料,模拟日光温室低温弱光逆境,研究了辣椒叶片中脯氨酸(Pro)、可溶性搪、可溶性蛋白含量的变化及其与耐低温弱光性之间的相关性.结果表明,15℃/5℃(昼/夜)、100μmol·m-2·s-1光照处理使辣椒叶片的Pro含量、可溶性糖含量升高,可溶性蛋白含量于处理前期升高,后期浇档?低温弱光处理10 d的可溶性蛋白含量和处理20 d的可溶性糖含量与辣椒耐低温弱光性呈显著正相关;10个品种的Pro含量与品种的耐低温弱光性呈极显著正相关,Pro的累积表现为保护作用;耐低温弱光性较强的品种'湘研1号'和较弱的品种'湘研16号'中Pro含量与耐性呈负相关,Pro的累积表现为伤害性反应.     

盐胁迫对青藏高原多年生牧草幼苗生理指标的影响

该试验采用不同浓度(0, 100, 200, 400, 600 mmol·L^-1)NaCl 溶液处理萌发的星星草、草地早熟禾、老芒麦和披碱草幼苗在6-15 ℃和20-25 ℃两种温度条件下生理生化的变化。结果表明: ①在不同盐浓度的胁迫下, 披碱草、草地早熟禾和星星草随着盐浓度的提高, 可溶性糖含量呈现增高的趋势; 而老芒麦呈现先升后降的趋势。且不同温度处理对牧草幼苗可溶性糖含量影响较大, 但在高盐浓度处理下, 温度对幼苗可溶性糖含量影响极显著, 6-15 ℃处理显著提高幼苗的可溶性糖含量。②随着盐浓度增加, 四种牧草游离脯氨酸含量均迅速积累, 且20-25℃处理下脯氨酸含量显著高于6-15 ℃处理。③盐胁迫导致四种牧草根尖过氧化氢含量和细胞死亡率的增加, 而6-15 ℃温度处理可以降低根尖过氧化氢的积累。④四种牧草随盐浓度增加根尖细胞死亡率均有增加的趋势, 6-15 ℃低温可以有效减轻盐胁迫对根细胞的损伤。⑤四种牧草在两种温度处理下随盐浓度增加株高都有所降低, 且在不同温度处理下牧草的株高没有显著性差异。     

低温对东方百合试管鳞茎解除休眠及生长的影响

以东方百合‘索邦’和‘西伯利亚’鳞片为外植体得到的一代试管小鳞茎为试材,研究0℃冷藏不同时间对试管鳞茎生理指标变化,以及试管鳞茎解除休眠和移栽后生长发育的影响。结果表明,冷藏0--28dN,随着冷藏时间的延长,试管鳞茎出苗率逐渐增加,冷藏处理28d达到最高,之后逐渐降低。冷藏期间,试管鳞茎中淀粉含量持续降低,而可溶性总糖和还原性糖含量表现出先升高后下降的趋势,冷藏处理28d的含量最高。同时,随着冷藏时间的延长,IAA和ZR含量逐渐升高,ABA含量逐渐下降,而GA。含量表现出先上升后下降的趋势,并且也在冷藏处理28dN-含量达到峰值。另外,采用隶属函数值对低温处理的试管苗栽培1年后所收获种球的数量、质量等指标进行评价,结果显示,均以低温处理28d时达到最大值。由此得出,0℃低温处理试管小鳞茎28d为解除休眠及促进生长发育的最适处理时间。     

不同LEDs光质下普通白菜开花以及花期生理特性的动态变化（英文）

以普通白菜品种‘苏州青’为试材,采用单因素随机区组设计的盆栽试验,将基质育苗后长至子叶展平时的幼苗转入荧光灯(FL,对照)、蓝光(B)发光二极管(LEDs)、蓝红复合光(BR)和红光(R)下进行照射处理至开花,考察不同光质对普通白菜开花以及花期光合色素含量、品质和碳代谢等的光效应,为利用人工光源调节普通白菜的育种周期提供理论指导。结果显示:(1)随着开花时间延长,普通白菜的开花数目均以R和BR处理显著高于FL;花蕾数目在处理100d时R和BR处理显著多于FL,但是在110和120d时B处理下明显多于FL。(2)随着花期延长,白菜叶片中的光合色素含量呈降低趋势,其在处理100d时表现为BR处理显著高于FL,而在110d时B处理最高,在120d时BR处理最高。(3)随着花期延长,叶片中可溶性蛋白和抗坏血酸含量也呈逐渐降低的趋势;可溶性蛋白含量均在B处理下较大,而抗坏血酸含量在100d时在B处理下最高,但是在110和120d时B和BR处理下较高。(4)随着花期延长,叶片中碳水化合物含量也逐渐降低,其中可溶性糖、蔗糖和淀粉含量均以R处理下最高。研究表明,与荧光对照相比,LEDs光源对普通白菜幼苗的营养生长和生殖生长更有效,其中蓝光有利于普通白菜的营养生长,而红光和蓝红复合光则有利于其生殖生长;可采用红光和蓝红复合光作为普通白菜育种的人工光源,有效促进其工厂化生产进程。     

不同温度处理对珠芽魔芋球茎休眠调控的影响

为探究不同温度处理对珠芽魔芋球茎休眠调控的影响，以珠芽魔芋叶面球茎为材料，在球茎休眠期设置昼/夜变温（24℃/9℃、24℃/13℃、24℃/17℃）、恒温（9℃、13℃、17℃、21℃）及室温处理，萌发期设置26℃、33℃催芽处理，分析不同温度处理后珠芽魔芋球茎在休眠 Ⅰ 期、休眠 Ⅱ 期以及萌发前期、中期、后期、末期的生物表型变化、内源生理变化规律及其休眠调控相关基因的变化情况。结果表明：（1）休眠期恒温处理有利于提高珠芽魔芋球茎的出芽比，其中13℃恒温打破休眠和萌发期33℃催芽处理球茎的发芽率最先达到峰值，且其出芽比最高。（2）休眠Ⅱ期的球茎淀粉含量低于休眠Ⅰ期，而其可溶性糖含量高于休眠Ⅰ期，13℃恒温处理球茎淀粉含量下降最快，其可溶性糖含量最高；前期恒温处理球茎淀粉、可溶性糖含量在萌发前期和萌发后期之间均存在显著性差异（P＜0.05），而前期昼夜变温处理球茎仅可溶性糖含量在萌发前期和萌发后期之间存在显著性差异（P＜0.05）。（3）珠芽魔芋球茎ABA含量在休眠 Ⅰ 期和休眠 Ⅱ 期逐渐增多，而其GA3含量逐渐减少，萌发期珠芽魔芋球茎ABA含量呈现“先升后降”的规律，26℃催芽处理的珠芽魔芋球茎GA3含量呈现“先升后降”的规律，33℃催芽处理的珠芽魔芋球茎GA3含量整体呈上升的趋势。（4）珠芽魔芋NCED基因表达量随着休眠程度的加深逐渐增加，而在萌发期逐渐减少，CYP707A基因表达量随着休眠的加深逐渐减少，而在萌发期表达量增加。研究发现，珠芽魔芋打破休眠的最佳温度为恒温13℃，促进萌发的最佳温度为33℃；随着珠芽魔芋打破休眠，球茎中的淀粉含量降低，可溶性糖含量升高；ABA含量“先升后降”，GA3含量“先降后升”；NCED和CYP707A基因可能是珠芽魔芋休眠调控中的关键基因。     

两种石蒜生长发育期鳞茎可溶性糖、蛋白质及POD活性的变化

以中国石蒜(Lycoris chinensis)与石蒜(Lycoris radiata)为材料,研究其生长发育期鳞茎可溶性糖、蛋白质含量及POD活性的变化。结果表明,在花芽分化前期,2种石蒜鳞茎可溶性糖、可溶性蛋白质含量均增加,并出现峰值,但从花芽分化后期直到花期结束,可溶性糖含量均持续下降;在花期,2种石蒜鳞茎可溶性蛋白质含量均处于高水平,花谢后明显下降;石蒜展叶期间鳞茎可溶性蛋白质含量明显增加,而中国石蒜花谢后可溶性蛋白质含量处于低水平。在花芽分化前期,2种石蒜鳞茎POD活性呈直线上升,但后期POD活性略有降低;花期后,2种石蒜鳞茎POD活性出现短暂的低谷,随后随着气温的降低而出现一致性上升。     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Analysis of twin of eyeless regulation during early embryogenesis in Drosophila melanogaster

The Drosophila Pax6 homolog twin of eyeless (toy) is so far the first zygotically expressed gene involved in eye morphogenesis in Drosophila. The study of its expression during embryogenesis is therefore informative of the initial events of eye development in Drosophila. We have analyzed how the initial expression domain of toy at cellular blastoderm is regulated. We show that the three maternal patterning systems active in the cephalic region (the anterior, terminal and dorsal-ventral systems) cooperate with zygotically activated gap genes to shape the initial expression domain of toy. Whereas Bicoid, Dorsal and Torso signaling synergistically act as activators, Hunchback, Knirps and Decapentaplegic act as repressors.     

Host plants of someRhinanthoideae (Scrophulariaceae) of eastern North America

Twenty three species in 11 genera were examined in the field to determine hosts. OnlyStriga asiatica andSeymeria cassioides have a narrow host range being restricted to grasses and pines, respectively. These are the only species which cause pronounced and sometimes serious host damage. The other species attach to a great diversity of hosts.     

Apoptotic Regulation of Caspase Activity

Intracellular cysteine aspartate-specific proteases (caspases) play both signaling and effector roles in realizing the program of cell death. Caspases function as proteolytic cascades unique for each cell type and signal triggering apoptosis. All parts of the proteolytic cascades are duplicated and controlled by feedback signals. Amplification cycles between pairs of caspases (the third and the sixth, the ninth and the third, the twelfth and the sixth, and others) help multiply the initial apoptotic signal. The presence of physiological inhibitors of apoptosis that directly interact with caspases creates a multilevel regulatory network of apoptosis in cell. The caspase proteolytic cascades are also regulated by sphingolipid secondary messengers, among them ceramide, sphingosine, and their phosphates. Moreover, an association of the caspase signaling with ubiquitin-dependent proteolysis is shown in cells. In particular, the use of extracellular activators and inhibitors of caspases allows irreversible activation of apoptosis in tumor cells or the prevention of apoptosis in cortical neurons under neurodegenerative diseases.     

广西青藓科分类学修订

通过对采自广西24个县(市)的1 147份青藓科植物标本的逐一鉴定及相关文献的查阅,确认有广西青藓科植物11属、44种,其中包括广西青藓科植物新记录属1属,即拟异叶藓属(Pseudokindbergia),新记录种7种,分别为匐枝青藓(Brachythecium procumbens)、阔叶尖喙藓(Oxyrrhynchium latifolium)、泛生尖喙藓(O. vagans)、拟异叶藓(Pseudokindbergia dumosa)、华东细喙藓(Rhynchostegiella sinensis)、长肋拟青藓(Sciurohypnum populeum)和弯叶拟青藓(S. reflexum)。该文提供了修订后的广西青藓科植物名录,并对其中的新记录属、种的主要形态学识别特征、生境和地理分布等进行了详细描述。     

Evaluation of antiprotozoal and antimycobacterial activities of the resin glycosides and the other metabolites of Scrophularia cryptophila

Resin glycosides are secondary metabolites exclusive to the convolvulaceous plants. In this study, crypthophilic acids A–C (1–3), the first resin glycosides occurring in another family (Scrophulariaceae), and the other constituents of Scrophularia cryptophila were examined for in vitro antiprotozoal and antimycobacterial potentials. Except for crypthophilic acid B (2), all tested compounds exhibited growth-inhibitory effect against Trypanosoma brucei rhodesiense, with l-tryptophan (6) and buddlejasaponin III (7) being the most potent ones (IC₅₀'s 4.1 and 9.7 μg/ml). In contrast, the activity towards Trypanosoma cruzi was poor, and only crypthophilic acid C (3), 6 and 7 were trypanocidal at concentrations above 40 μg/ml. With the exception of 2 and 6, all compounds were active against Leishmania donovani. Harpagide (4) and 3 emerged as the best leishmanicidal agents (IC₅₀'s 2.0 and 5.8 μg/ml). Only compounds 3, 6 and 7 showed antimalarial activity against Plasmodium falciparum with IC₅₀ values of 4.2, 16.6 and 22.4 μg/ml. Overall the best and broadest spectrum activity was presented by compounds 3 and 7, as they inhibited all four parasitic protozoa. None of the isolates had significant activity against Mycobacterium tuberculosis (MICs >100 μg/ml) or were toxic towards mammalian (L6) cells. This is the first report of antiprotozoal activity for natural resin glycosides, as well as for harpagide (4), acetylharpagide (5), tryptophan (6) and buddlejasaponin III (7).     

New species of Peruvian Orchidaceae III

Sixteen new species are proposed in the generaAckermania, Dressleria, Epidendrum, Maxillaria, Oncidium, Rodriguezia, Sigmatostalix, andTrigonidium. All new species are illustrated.Maxillaria vittariifolia L. O. Williams is newly recorded for Peru. A key is provided forTrigonidium of Peru.Trigonidium loretoense Schltr. andT. peruvianum Schltr. are lectotypified.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.