Factors influencing seed germination of medicinal plant Salvia aegyptiaca L. (Lamiaceae)

Salvia aegyptiaca is a xerophytic perennial herb belongs to the Lamiaceae family commonly used for medicinal purposes. Laboratory experiments were carried out to assess the effects of temperature and salinity on seed germination and recovery responses after transferring to distilled water. Temperatures between 10 and 40 °C seem to be favourable for the germination of this species. Germination was inhibited by either an increase or decrease in temperature from the optimum (30 °C). The highest germination percentages were obtained at 0 mM NaCl; however, the increase of solution osmolalities progressively inhibited seed germination. The germination rate decreased with an increase in salinity for most of tested temperatures, but comparatively higher rates were obtained at 30 °C. Salt stress decreased both the percentage and the rate of germination. An interaction between salinity and temperature yielded no germination at 300 mM NaCl. By experimental transfer to distilled water, S. aegyptiaca seeds that were exposed to moderately saline conditions recovered and keep their ability to germinate mostly at low temperatures. At 300 mM NaCl, germination recovery decreased with increasing temperature and it was completely inhibited at 40 °C.     

外源激素ABA影响新疆荒漠盐生植物异子蓬异型种子萌发机制

以新疆荒漠盐生植物异子蓬(Suaeda aralocaspica)异型种子为材料,通过外源ABA直播(长时间)与浸种(短时间)处理分别研究不同浓度(0、0.5、1.0、5.0、10.0μmol/L)ABA对异型种子萌发、幼苗生长的影响,并通过定量PCR技术分析与萌发相关的ABC转运蛋白基因、丝裂原活化蛋白激酶激酶基因和DNA修复和转录因子基因在5.0μmol/L ABA处理下的表达规律,探讨外源ABA影响异子蓬异型种子萌发差异的机制。结果显示:(1)外源ABA直播处理下,褐色种子萌发及幼苗生长均受到明显抑制,黑色种子的萌发和幼苗生长在低浓度被促进,较高浓度被显著抑制;短时间浸种处理,能够同时促进异型种子的萌发及幼苗生长,且随ABA浓度增加促进效应增强。(2)直播萌发后,褐色种子中3个基因的表达量与对照相比均不变或降低表达(除了DNA修复和转录因子基因在8 h显著升高),黑色种子与对照相比均上调表达(除了ABC转运蛋白基因在8h显著下调);短时间浸种萌发后,褐色种子中3个基因的表达量均比对照显著升高,黑色种子中升高不明显。基因表达规律与种子萌发结果趋势一致,暗示ABA浸种可能触发了异子蓬种子萌发内在机制并对随后的萌发过程产生促进作用。而黑色种子对ABA处理表现出较好的萌发响应,可能是其幼苗能抵御荒漠地区逆境环境的重要原因。     

武汉地区西部食蚊鱼的生长、死亡系数及种群补充模式

基于2012年4月—2013年3月在武汉地区两样点调查的西部食蚊鱼数据,运用FAO开发的长度频率数据分析软件FiSATⅡ对西部食蚊鱼的生长、死亡系数以及种群补充模式进行了估算。西部食蚊鱼全长范围为8.30-44.86mm,其中优势全长为16-26 mm,占总数的69.17%;雌雄性别为2.63:1,与1:1存在显著性差异;鳞片观察发现仅存在0~+、1~+两个年龄组;雌雄样本全长与体重的关系式分别为W=4.686×10~(-6)L~(3.299)(R~2=0.953),W=1.008×10~(-5)L~(2.989)(R~2=0.903);von Bertalanffy生长方程各参数为:雌性样本极限全长L_∞=45.20 mm,生长系数k=0.52 a~(-1),起始生长年龄t_0=-0.47a,雄性样本极限全长L_∞=33.60 mm,生长系数k=0.53 a~(-1),起始生长年龄t_0=-0.50 a;雌性样本和雄性样本的自然死亡系数M分别为1.64 a~(-1)、1.81 a~(-1),而总死亡系数Z分别为2.29 a~(-1)、2.37 a~(-1);种群补充模式表明,每年4-9月份为西部食蚊鱼的主要补充期。西部食蚊野生种群表现出了寿命短、生长速度快、自然死亡率高、种群补充时间长等特征,表明该物种是一种典型的r对策物种。据此我们提出了针对性的防控措施:阻止其引入,尽早发现并根除该物种。     

Development and mortality of the first naupliar stages of Eurytemora affinis (Copepoda, Calanoida) under different conditions of salinity and temperature

As a prevalent species complex in temperate estuaries and salt marshes of the Northern Hemisphere, populations of Eurytemora affinis that inhabit these environments must be adapted to salinity fluctuations. Some populations have invaded freshwater environments. In this work, we focus on the combined effects of temperature and salinity fluctuations on mortality rates and development time of the first naupliar stages under starvation. Two temperatures (10 and 15 °C) and eight salinities, ranging from 0 to 35 psu are investigated. We show (i) that among all experimental conditions the optimal temperature and salinity for naupliar survival and development are 15 psu and 15 °C, and (ii) that only the most extreme salinities (i.e. 0 and 35 psu) have a negative effect on naupliar survival. Nauplii develop faster and reach a higher developmental stage at 15 than at 10 °C, independent of salinity. The relevance of this metabolic adaptive pattern is discussed in the general framework of in situ behavior, tidal forcing and biogeographic variability, as well as the potential sources of the observed individual variability.     

Establishment and Dispersal ofUrophora affinis(Diptera: Tephritidae) andMetzneria paucipunctella(Lepidoptera: Gelechiidae) in Southwestern Virginia

Two European gall-producing insects,Urophora affinisFrfld. (Diptera: Tephritidae) andMetzneria paucipunctella(Zeller) (Lepidoptera: Gelechiidae) were introduced into Virginia in 1986 for biological control of spotted knapweed (Centaurea maculosaLam.). Adults ofU. affinis(n = 2625) andM. paucipunctella(n = 450) were released at two sites in Montgomery County, Virginia, and their populations were monitored yearly by dissecting spotted knapweed flower heads. Beginning in 1992, knapweed samples collected at various distances from the release sites were checked for dispersal.U. affinisis well established and is spreading slowly. The number of larvae per flower head and the seed numbers are inversely related as plants with the greatest number of larvae per spotted knapweed head had the lowest number of seeds. Knapweed density has declined at one of the release sites which had the highest rate of infestation byU. affinis.Establishment of the moth,M. paucipunctella,is less certain as it has been recovered at a very low level from only one site.     

大菊头蝠和中菊头蝠分娩声波的特征

动物的声学信号在信息传递和维持社群稳定等方面扮演了非常重要的角色,特别是对于占据夜空生态位并集群生活的蝙蝠,它们日间栖息于几乎没有光照的洞穴中。这些夜行性蝙蝠主要借助声信号介导重要生活史事件,包括生殖、觅食、通讯和空间导航等。分娩是动物生殖活动中的关键一环,决定了后代甚至母体的生死。一直以来野生动物的分娩行为,特别是分娩叫声鲜有研究。本研究以大菊头蝠(Rhinolophus luctus)和中菊头蝠(R. affinis)为研究对象,捕捉并录制其在分娩过程中的声信号,进而开展声谱分析和统计分类。研究发现,大菊头蝠和中菊头蝠在分娩过程中分别发出了6种和4种类型的交流声波。基于子集验证的判别式分析表明,大多数的音节类型都被正确划分。纳入多种声学参数的多维尺度分析显示,不同音节类型在三维图像中差异显著。此外,欧几里得距离分析发现,种间的叫声差异远大于种内的叫声差异。本研究结果可为深入揭示夜行哺乳动物的叫声功能和发声机制提供参考。     

紫翅猪毛菜、钠猪毛菜不同个体大小繁殖分配差异及随海拔的变化

以新疆准噶尔盆地藜科猪毛菜属植物紫翅猪毛菜(Salsola affinis C.A.Mey)、钠猪毛菜(Salsola nitraria Pall)为研究对象,用繁殖分配比例的方法对比分析了两种猪毛菜不同海拔同一种群内不同个体大小繁殖分配的特点,并用异速生长模型分析了不同海拔繁殖生物量与营养生物量之间分配与个体大小的依赖关系。结果发现:1)不同海拔繁殖生物量(R)与营养生物量(V)呈不同程度的异速生长。紫翅猪毛菜随海拔的升高R-V的异速生长斜率显著升高,截距随海拔的升高没有显著增加;而钠猪毛菜的斜率随海拔升高显著降低,截距则显著升高。2)紫翅猪毛菜在较低海拔个体大小与繁殖分配呈负相关,在较高海拔呈正相关;钠猪毛菜在较低海拔个体大小与繁殖分配呈正相关,在较高海拔呈负相关;两种猪毛菜繁殖分配的适应对策相反。3)将同一种群个体大小分成大、中、小3种类型,多重比较发现紫翅猪毛菜在较低海拔,中小个体的繁殖分配显著高于大个体的繁殖分配;在较高海拔,大个体的繁殖分配显著高于中小个体的繁殖分配。钠猪毛菜在较低海拔,大个体的繁殖分配显著高于中、小个体的繁殖分配;在较高海拔,小个体的繁殖分配显著高于大、中个体的繁殖分配。综合分析认为:两个物种随海拔变化产生不同的繁殖分配策略,除遗传效应外,环境和个体大小对钠猪毛菜繁殖分配的变化均产生重要影响,而紫翅猪毛菜繁殖分配的变化主要由海拔差异导致。由于微生境对同一种群的个体大小产生影响,进而产生不同的繁殖分配模式,所以在干旱区更应重视个体大小对繁殖分配的影响。     

中国耳草属(茜草科)植物新记录种

首次报道了蓝花耳草(Hedyotis affinisRoem.& Schult.)在我国的分布新记录,并对其形态特征进行了详细描述。     

卵胎生入侵种食蚊鱼的两性异形和雌性繁殖输出

检测了卵胎生入侵种食蚊鱼(Gambusia affinis)繁殖期个体大小和形态特征的两性异形以及雌性繁殖输出。结果表明,繁殖期,雌性个体的数量显著大于雄性个体,雌性个体的体长显著大于雄性个体,食蚊鱼属于偏向雌性的两性异形。以体长为协变量的One-way ANCOVA及后续的Tukey's检验显示,特定体长食蚊鱼的雌性个体的头宽、眼间距、体宽和体重均显著大于雄性个体;头长和尾鳍长的两性间差异不显著。6个形态特征变量的主成分分析(Eigenvalue≥1)发现,前2个主成分共解释65.1%的变异。头宽、眼间距、体宽和体重在第一主成分有较高的正负载系数(解释45.4%变异),头长在第二主成分有较高的负负载系数(解释19.7%变异)。食蚊鱼的繁殖输出与母体个体大小的线性回归显示,窝仔数和窝仔重均与母体体长、体重呈显著的正相关;食蚊鱼的繁殖输出与母体局部特征的线性回归显示,窝仔数和窝仔重均与母体头宽、眼间距和体宽呈显著的正相关。窝仔数与后代个体的平均体长呈显著的正相关、与后代个体的平均体重相关不显著,后代个体大小与数量不发生权衡。食蚊鱼繁殖期的性别比例、个体大小和局部形态特征的两性异形受生育力选择、性选择、生态位分化、食物竞争等多种选择压力的作用,也有利于该物种种群扩张和快速入侵。     

紫萼藓科植物一新种--曹氏紫萼藓北大核心CSCD

描述了新疆天山山脉紫萼藓科(Grimmiaceae)紫萼藓属(Grimmia)一新种——曹氏紫萼藓(Grimmia caotongiana D.P.Zhao,S.Mamtimin&S.He)。该新种与无齿紫萼藓(Grimmia anodon Bruch&Schimp.)最为相似,不同之处在于新种茎叶和雌苞叶均无白色毛尖,叶中部边缘背卷;近中肋细胞通常无色透明,且细胞壁比边缘细胞明显加厚。该研究对新种——曹氏紫萼藓进行了详细的特征描述,并提供了植物体形态显微解剖彩色照片以及相近种的分类学讨论。     

Germination responses of Diplotaxis harra to temperature and salinity

Diplotaxis harra (Forssk.) Boiss, an annual herb in the family of Brassicaceae, is widely distributed in many sandy and gypseous areas in southern Tunisia. Laboratory experiments were carried out to assess the effects of temperature and salinity on seed germination and recovery responses after seed transfer to distilled water. The germination responses of the seeds in complete darkness were determined over a wide range of temperatures (5, 10, 15, 20, 25 and 30 °C) and salinities (0, 50, 100, 150 and 200 mM NaCl). Germination was inhibited by either an increase or decrease in temperature from the optimal temperature (15 °C). Highest germination percentages were obtained under non-saline conditions and an increase in NaCl concentrations progressively inhibited seed germination. Rate of germination decreased with an increase in salinity at all temperatures but comparatively higher rates were obtained at 15 °C. Salt stress decreased both the percentage and the rate of germination. An interaction between salinity and temperature yielded no germination at 200 mM NaCl. Seeds were transferred from salt solution to distilled water after 20 days, and those from low salinities recovered at all temperatures. At NaCl concentration of 200 mM, the recovery of germination was completely inhibited.     

Effects of salinity, temperature and individual variability on the reproduction of Eurytemora affinis (Copepoda; Calanoida) from the Seine estuary: A laboratory study

The brackish water copepod Eurytemora affinis is the most abundant copepod species in the low salinity zone (2-15) of the Seine estuary. Despite its ecological importance, little is known about its population dynamics in the Seine. We studied the effects of temperature (10 °C and 15 °C) and salinity (5, 15 and 25) on reproduction under non-limiting food conditions. We used experiments to determine multiple reproductive parameters for E. affinis. In all experiments, we fed E. affinis a mixture of Rhodomonas marina and Isochrysis galbana. Couples of pre-adult females (C5) and adult males were mated until the female extruded a clutch of eggs and then individual females were observed every 6-12 hours until death to determine (a) embryonic development time, (b) inter clutch time and (c) clutch size throughout their adult lifespan. All reproductive parameters were negatively affected by low temperature (10 °C) and by high salinity (25). At 10 °C and a salinity of 25, mortality during the post-embryonic period was extremely high (85%). Differences in all reproductive parameters between salinities 5 and 15 were minimal. From 15 °C to 10 °C mean latency time (time between hatching of eggs and extrusion of new ones) increased from 0.8 to 2.25 days, the mean embryonic development time from 2.2 to 3.2 days and the mean clutch size decreased from 38 to 22 eggs female^- 1. The mean clutch size decreased when females reached a critical age. The hatching success was high (near 95%) under all conditions except at high salinity. Egg production rates showed no significant differences between salinities 5 and 15 and were significantly higher at 15 °C (13 eggs female^- 1 day^- 1 at salinity 5 and 15) than at 10 °C (4 eggs female^- 1 day^- 1). These values at 15 °C were higher compared to those from other populations of E. affinis in estuaries or lakes. The high reproductive potential of E. affinis from the Seine estuary at 15 °C and low salinities explain its high densities in the low salinity zone during spring and early summer.     

兴安落叶松(Larix gmelinii)火后种子萌发影响因子

林火干扰是影响兴安落叶松林结构和功能的主要因子之一。兴安落叶松种群火后更新受多种因子的影响,并决定着该群落演替轨迹。通过在大兴安岭呼中自然保护区的火烧迹地内设置原位控制实验,利用增强回归树分析方法,量化研究了落叶松火后恢复初期不同影响因子（温度、有机质层厚度、覆盖度等）对种子萌发的相对重要性。研究结果表明：落叶松火后种子萌发的最主要影响因子为温度,第二影响因子为种源,第三影响因子为草本覆盖度,分别解释了幼苗数量变异的28.51%、22.40%、20.66%;各影响因子的相对重要性在不同地形条件下有明显差异：温度在山坡顶部和阳坡底部占有重要影响,种源在阳坡中部和阴坡中部最为重要,土壤含水量在阴坡底部占有重要地位。同时,去除土壤表面有机质可以显著提高种子萌发数量,去除地面杂草则会使种子萌发数量降低。从研究结果可知,落叶松火后种子萌发在不同地形（环境条件）下的限制因子不同,人工辅助需因地制宜采取相应措施,才能更有效地促进种子萌发与森林恢复。     

Interactive effects of salt and alkali stresses on seed germination,germination recovery,and seedling growth of a halophyte Spartina alterniflora (Poaceae)

Soil salinization and alkalinization frequently co-occur in nature, but there is little information on the interactive effects of salt and alkali stresses on plants. Seed germination and early seedling growth are crucial stages for plant establishment. We investigated the interactive effects of salt and alkali stresses on seed germination, germination recovery and seedling growth of a halophyte Spartina alterniflora. Seed germination percentage was not significantly reduced at low salinity (≤ 200 mM) at pH 6.63–9.95, but decreased with increased salinity and pH. Ungerminated seeds germinated well after transfer to distilled water from treatment solutions, indicating that seeds can remain viable in high salt–alkaline habits. Shoot growth was stimulated at low salinity and pH, but decreased with increased salinity and pH. Radicle elongation decreased sharply with increased salinity and pH, and was significantly inhibited when pH ≥ 9.0, indicating that the radicles are very sensitive to salt–alkaline stress. The deleterious effects of salinity or high pH alone were less than when combined. A reciprocal enhancement of salt and alkali stresses is a characteristic feature for salt–alkaline stress. Stepwise regression analysis indicates that salinity is the dominant factor, while pH and buffer capacity are secondary for salt–alkaline mixed stress.     

Effects of temperature and light on cyst germination and germinated cell survival of the noxious raphidophyte Heterosigma akashiwo

The effects of temperature and light on the germination of Heterosigma akashiwo cysts were examined using bottom sediments collected from Hakata Bay, Japan. In a suspension of mixed sediment and seawater in the temperature range of 5–30 °C, motile cells emerged within 3 weeks, but at ≤12 °C the cell numbers were markedly lower and the emergence of motile cells delayed. When suspension samples incubated at various temperatures were moved to 20 °C and incubated, only a few additional motile cells emerged. The number of motile cells germinated in the dark was significantly lower than under light conditions. When suspension samples incubated in the dark were exposed to light, only a few additional motile cells emerged. These results indicate that the initiation of germination in Heterosigma cysts suspended in seawater is not dependent on temperature and light conditions, although the speed of the germination process is affected by temperature, and cell survival just after germination is strongly affected by temperature and light.     

新疆地图衣属地衣分类学研究

该研究以新疆的地图衣科(Rhizocarpaceae)地图衣属(Rhizocarpon)100余份地衣标本为材料,通过形态解剖学观察、化学成分分析及分子学鉴定的方法了解新疆地图衣属地衣的物种多样性。结果表明:(1)鉴定出7种地图衣属地衣,包括1个中国新记录种,命名为淡黄色地图衣(R.atroflavescens),6个常见种分别是黑红地图衣(R.badioatrum)、灰地图衣(R.disporum)、双孢地图衣(R.geminatum)、地图衣(R.geographicum)、巨地图衣(R.grande)和岩表地图衣(R.superficiale)。(2)编制了新疆22种地图衣属地衣的分种检索表。(3)系统发育分析结果表明,新疆地图衣属地衣的分子鉴定与形态解剖特征结果一致,更准确地证明淡黄色地图衣为中国新记录种。(4)对已报道的新疆22种地图衣属地衣的地区分布及海拔分布统计显示,新疆22种地图衣属地衣在世界各地均有分布,其中亚洲分布最丰富;该22种地图衣属地衣从低海拔到高海拔都有分布,且各海拔高度物种分布不均匀,总体在高海拔地区分布的物种较多。     

新疆鳞网衣属地衣的初步研究

采用形态解剖、化学等传统分类方法,对新疆天山的鳞网衣属地衣进行了初步研究,发现该属的3个种,其中脑状鳞网衣（Psora cerebriformis W. A. Weber）和小红褐色鳞网衣［Psora luridella (Tuck.) Fink］是中国新记录种。文中对鳞网衣属3个种进行了详细的描述,并提供了相关彩色图片。     

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.     

镉胁迫对瘤突苍耳、苍耳及其杂合体种子萌发与幼苗生长的影响

入侵种与本地种杂交可能会改变其某些性状,影响其生理生化过程,增强其对一些重金属的耐受性。镉是目前造成土壤污染的主要重金属元素之一,为探讨杂交是否能够增强植物对重金属镉的耐受性,采用培养皿滤纸法比较了不同浓度镉(0,10,40,80和120 mg/L)处理下瘤突苍耳(Xanthium strumarium)、苍耳(Xanthium sibiricum)及二者杂合体(X.strumarium♀×X.sibiricum♂,X.sibiricum♀×X.strumarium♂)种子萌发与幼苗生长情况。结果表明:1)入侵种瘤突苍耳与本地种苍耳之间存在杂交现象;2)镉促进了杂交瘤突苍耳(X.strumarium♀×X.sibiricum♂)种子的萌发,当镉浓度为80 mg/L时,其萌发率、发芽势、发芽指数最高;3)杂交瘤突苍耳在80、120 mg/L镉处理下根长和叶绿素含量低于瘤突苍耳,但子叶受到的氧化胁迫并未高于瘤突苍耳。研究结果显示,杂交有可能提高了瘤突苍耳在高浓度镉胁迫时对重金属镉的转运能力,幼苗根系吸收大量的镉并向上运输给子叶,导致根系生长受到抑制、子叶叶绿素含量下降,抗氧化酶系统可能在降...     

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.