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1.
杉木球果麦蛾生物生态学特性的研究   总被引:2,自引:0,他引:2  
杉木球果麦蛾是危害杉木球果和种子的一个新害虫,在中国危害杉木,广泛分布于中国南部。该虫以幼虫钻蛀球果的苞鳞、果轴及种子,使球果变色、干枯及畸形。本文报道了该虫的生物生态学特性。  相似文献   

2.
Nystroemia reniformis (Kawasaki) comb. nov. is proposed based on specimens showing organic connections between Chiropteris reniformis Kawasaki and Nystroemia pectiniformis Halle from the Lower Permian of Dengfeng in Henan. Vegetative leaf has a long petiole, reniformed, cordate at the base, entire or slightly undulate at the margin;veins are fine, bifurcating repeatedly and finally becoming reticulate and forming polygonal or rhomboidal meshes.Fertile shoot arises from bract axils. The form of the bract is identical to that of a vegetative leaf. Ovuliferous organ arises from the axU of leafy organ, or in other ease, both ovulfferous and leafy organs irregularly arise from the axis of the fertile shoot respectively. Numerous bicornute platyspermic seeds are arranged in two rows, obconical, with micropyle pointing upwards. It may represent a new extinct gymnosperms.  相似文献   

3.
杉木传粉生物学的观察   总被引:4,自引:1,他引:4  
观察了杉木雌、雄球花在树冠上的分布规律及开花,传粉的全过程,发现雌球花主要分布在树冠中,上部,即Ⅰ~Ⅳ年龄段,约占总量的77%,雄球花的分布趋势与雌球相反,在相应部位仅为总量的40%,雌球花开放期约7d,可授期3-5d。雄球花的撒粉期与雌球花的可授期是吻合的,传粉过程中对花粉撒落的定量测定表明:睛朗、干燥的天气伴随一定的风力是花粉传播的必要条件,对授粉后幼果的发育及胚珠所接受花粉的多寡与种子发育的  相似文献   

4.
For the past several years, a novel dwarf disease has been observed on rice (Oryza sativa) in some regions of Guangdong Province and Hainan Province, southern China. Infected plants showed stunting, dark leaf and small enations on stem and leaf back. Typical Fijivirus viroplasma containing crystalline arrayed spherical virons approximately 70--75 nm in diameter and tubular structures were detected in ultrathin sections by an electron microscope in parenchyma phloem cells of the infected plants. The virus was transmitted to rice seedlings by white-backed planthoppers, Sogatella furcifera (Hemiptera: Delphacidae), collected in the diseased fields. Analysis of dsRNA extracts from infected plants revealed ten linear segments, which were similar to the electrophoretic profile of Rice black-streaked dwarf virus (RBSDV). RT-PCR with a single primer which matched to a linker sequence ligated to both 3' ends of the viral genomic dsRNAs resulted in amplification of genome segments 9 (S9) and 10 (S10) cDNA products. The complete nucleotide sequences of S9 and S10 were obtained from clones of the RT-PCR amplicon exhibited characteristic properties of Fijivirus including low GC content (34.5% and 35.6%), genus conserved 5' and 3' termini sequences and similar genome organization. Blast searches indicated that the sequences of S9 and S10 shared 68.8%--74.9% and 67.1% --77.4% nucleotide identities with those of viruses in the Fijivirus group 2, respectively. These values were similar to those among other viruses in the Fijivirus group 2 and considerably lower than those among RBSDV isolates. Phylogenetic trees based on S9 and S10 nucleotide sequences and their putative amino acid sequences showed that this virus represented a separate branch among other Fijiviruses. The virus was also detected by a nested RT-PCR assay in corn (Zea mays), barnyard grass (Echinochloa crusgalll), Juncellus serotinus and flaccidgrass (Pennisetum flaccidum) in and/or adjacent to the infected rice fields. I  相似文献   

5.
广西桂花树的桑名蚧属新种(同翅目:珠蚧科)   总被引:1,自引:0,他引:1       下载免费PDF全文
报道发现于广西桂林的新害虫桂花桑名蚧KuwaniaasmanthusYangetHu.详细记述并描绘了新种的形态特征,与本属种类进行了比较.附有我国桑名蚧属Kuwania已知种的检索表。  相似文献   

6.
沈阳城市庭院及道路绿化木本植物的应用现状分析   总被引:3,自引:0,他引:3  
对沈阳市庭院及道路绿化木本植物的应用和配置进行了分析,结果表明:庭院主要应用的绿化木本植物有69种,但占优势的只是少数几个种,按数量多少排在前10位的树种占庭院木本植物总量的68%;针叶树应用比例相对较低,平均为13.29%,而阔叶乔木占总株数的40.7%,花灌木的应用比例差异较大.道路主要应用的木本植物50余种,其中针叶树6种、阔叶乔木28种、花灌木16种.按数量排在前10位的树种占调查道路木本植物个体总量的59.7%.从株数上看,针叶树平均仅占8.1%,阔叶乔木占61%,花灌木占30.9%.道路树木针阔比仅1∶11;乔灌比7∶3.道路绿化存在植物品种过于单一,乔灌比过大、针阔比偏小的问题.  相似文献   

7.
To study the modulation mechanism of the middle brain of the Gekko to the locomotion, we introduced a stereotaxic method first in literature and developed an apparatus suitable for Gekko gecko, the biggest wall and ceiling climber in nature. We defined the bregma and nasal points as reference points, selected the bilateral infraorbital margin and top point of the maxillary tooth for locating and fixing, and set up the line passing through the bregma and paralleling to a line connecting the bilateral infraorbital margin as x axis. Then, we defined a horizontal plane in the stereotaxic instrument, passing through x axis and the certain point which is 4.8 mm exactly above the nasal point, as the XOY plane; the sagittal plane, i.e. the YOZplane, is the plane which is perpendicular to x axis and passes through the bregma; the plane, i.e. the XOZ plane, which passes through x axis and is perpendicular to the horizontal plane is the coronal plane. We designed a set of head holder which includes three parts: bilateral infraorbital margin clamps, a gecko adaptor holding the rostral side of the upper jaw. The allocation and operation of the head holder is accurate and simple, and the device is low in cost and compatible with standard stereotaxic instrument.  相似文献   

8.
仙菜科Ceramiaceae是重要的海洋大型红藻类群,具有重要的研究价值和经济价值,但因其个体微小脆弱、形态多变等,分类上还存在许多不足。本研究利用生物冷冻切片及显微拍照等技术,通过形态解剖方法,对2019-2021年采自我国秦皇岛沿岸海域的仙菜科红藻进行分类学研究。经鉴定,样品中包括仙菜属Ceramium 3种,即波登仙菜Ceramium boydenii Gepp、三叉仙菜C.kondoi Yendo和孙氏仙菜(新拟名)C.sungminbooi J.R.Hughey et G.H.Boo,其中孙氏仙菜为我国新纪录种;对丝藻属Antithamnion 1种,即多姿对丝藻Antithamnion defectum Kylin;绢丝藻属Callithamnion 1种,即绢丝藻Callithamnion corymbosum(Smith)Lyngbye。本文对新纪录种及其他物种进行详细的形态特征描述,提供了解剖学特征图片及生物地理分布信息等内容。研究结果丰富了中国仙菜科的物种多样性。  相似文献   

9.
云南鲤科鱼类二新种记述   总被引:5,自引:0,他引:5  
 描记采于云南东部的鲤科鱼类二新种,命名为罗平金线鱼巴Sinocyclocheilus luopingensis Li et Tao,sp.nov.和长鳍直口鲮Rectoris longifinus Li Mao et Lu,sp.nov.,前者头的背面下凹,但不呈鸭嘴形,鼻孔也开始前移到吻端,侧线鳞51,体鳞大,胸鳍长,后伸接近腹鳍起点等综合特征区别于该属所有已知种;后者各鳍较长,背鳍最长鳍条大于头长,后压达臀鳍基中部上方,胸鳍后伸达腹鳍,腹鳍后伸达臀鳍起点,臀鳍后伸达尾鳍基,体侧无一条黑色带伸达尾鳍基,可明显区别于直口鲮Rectoris posehensis Lin.  相似文献   

10.
薄壳山核桃雌雄花芽分化外部形态与内部结构的关系   总被引:1,自引:0,他引:1  
【目的】 观察薄壳山核桃品种‘Pawnee'(雄先型)的雌雄花花芽分化,了解控花控果的花期调控关键过程。【方法】以该品种为试材,通过物候学定期观察,结合石蜡切片技术、番红固绿对染,对其花芽外部形态变化和解剖结构进行研究。【结果】薄壳山核桃‘Pawnee'雄花芽4月上旬次第进入雄花序分化期、雄花原基分化期、花萼原基分化期、雄蕊原基分化期、花药分化期、花粉囊和花粉粒形成期; 与之对应的形态变化表现为雄花芽嫩绿柔软褐变雄花芽膨大雄花芽鳞片开裂雄花序伸长小花膨大苞片开裂花药变黄色。雌花芽顶生混合芽的分化从4月中旬进入形态分化临界期后,历经雌花花序分化期、花柄原基和雌花原基分化期、花被原基分化期、苞片原基分化期、花萼原基分化期、雌蕊原基分化期和胚珠分化期。与之对应的形态变化表现为:雌花芽鳞片黄绿色变至褐色雌花芽褐色变成灰绿色鳞片逐渐张开鳞片脱落幼叶展开小花原始体出现和膨大露出柱头花柱伸长。【结论】雌雄花芽外部形态直观反映内部结构变化,可方便快捷地判断薄壳山核桃雌雄花芽分化时期。  相似文献   

11.
【目的】阐明中山针阔混交林群落的物种多样性形成机理、分异规律及维持机制。【方法】在全面踏查的基础上,通过建立12块20m×20m的调查样地,研究中山针阔混交林的植物群落组成、植物多样性及分异规律。【结果】银杉混交林共有植物56科76属94种,长苞铁杉混交林共有植物51科78属103种,广东五针松混交林有30科43属66种,小叶罗汉松混交林有29科38属49种。银杉混交林的针阔叶树优势种分别是银杉(Cathaya argyrophylla,重要值IV为34.86)、长苞铁杉(Tsuga longibracteata,47.70)、五列木(Pentaphylax euryoides,27.69)、信宜杜鹃(Rhododendron faithiae,18.07);长苞铁杉混交林相应为长苞铁杉(63.44)、五列木(51.03)、马蹄荷(Exbucklandia populnea,13.24);广东五针松混交林为广东五针松(Pinus kwangtungensis,43.19)、五列木(59.09)、大头茶(Polyspora axillaris,44.49)、马蹄荷(26.10);小叶罗汉松混交林为小叶罗汉松(Podocarpus wangii,58.22)、福建柏(Fokienia hodginsii,32.89),南华杜鹃(Rhododendron simiarum,66.31)。中山区4种混交林中乔木层的物种丰富度没有显著差异(P0.05),而灌木层和草本层的物种丰富度存在显著差异(P0.05),乔木层和灌木层的植物多样性指数无显著差异(P0.05);长苞铁杉混交林中草本层的物种多样性指数显著高于广东五针松混交林(P0.05);其它类型间差异不显著(P0.05)。【结论】中山区特殊的气候和土壤条件是针阔混交林形成的主要原因,而作为优势种的针阔叶树种的生态生物学特性是维持中山区针阔混交林物种多样性的关键。  相似文献   

12.
Asian origin for Polystichum (Dryopteridaceae) based on rbcL sequences   总被引:8,自引:2,他引:6  
Chloroplast rbcL sequences of 60 species of Polystichum sensu lato (s.l.), including 23 new sequences from southwest China, were used to assess the phylogenetic relationships within the genus. On the basis of estimated evolution rate of rbcL gene and the genetic distance data that passed relative-rate tests, we further estimated the divergence times between some clades of the genus. The phylogenetic relationships were inferred using the neighbor-joining and maximum-parsimony methods, both methods producing trees with completely congruent topology. These trees reveal that all species of Polystichum s.l. in this study (including Cyrtomium and Cyrtomidictyum) form a monophyletic group. The basal split in Polystichum s.l. separates a clade with all Asian members from a clade containing other species from all over the world. The phylogenetic and divergence time estimation results lead us to suggest that Polystichum s.l. originated in Asia in the late Late Cretacous (≈76 Ma) and migrated into other places in the world in early Eocene(≈46 Ma).  相似文献   

13.
记述了上海蝶类一新记录种:无趾弄蝶(Hasora anura de Nicéville,1889),简要描述了其形态特征,并提供成虫标本照和雌外生殖器解剖图,给出了上海地区趾弄蝶属分种检索表,同时列出相关生物学和分布信息.  相似文献   

14.
Phylobetadiversity incorporates phylogenetic information and beta diversity,and can account for the ecological similarities between communities with a phylogenetic perspective.Although different phylobetadiversity indices reflect differences in different characteristics between communities,the results of different phylobetadiversity indices are not comparable.In this study we examined phylobetadiversity indices for a 24-hm 2 plot in the Gutianshan National Nature Reserve.It was found the abundanceweighted D pw was almost identical to Rao’s D of Rao’s quadratic entropy.PhyloSor had a similar ecological meaning and algorithm to UniFrac.Although Dnn was different in definition from UniFrac and PhyloSor,they were all strongly correlated.The effect of species abundance on phylobetadiversity was not significant when scales were relatively small,but was significant at larger scales.These contrasts likely resulted from reductions in evenness in communities as scales increased.P ST and Rao’s H better reflected the distance-decay changes caused by spatial and habitat variation than other indices at larger scales,whereas AW-D nn and D nn better reflected these changes at small scales.  相似文献   

15.
Virus isolate Y1 was obtained from tobacco showing curly shoot symptoms in Baoshan, Yunnan Province. Whitefly transmission test and virion morphology observation showed that it is a begomovirus. In reactions with 14 monoclonal antibodies raised against begomoviruses, Y1 was readily differentiated from begomoviruses reported in China, Pakistan and India. The complete nucleotide sequence of DNA-A was determined, it contains 2746 nucleotides, with two ORFs in virion-sense DNA and four ORFs in complementary-sense DNA. Comparisons with total DNA-A, intergenic region and deduced amino acid sequences of individual ORFs showed that Yl is a distinct Begomovirus species, for which the name Tobacco curly shoot virus (TCSV) is proposed. The total DNA-A of TCSV is most closely related to that of Tomato leaf curl virus from India (85% sequence identity). In contrast, the deduced coat protein of TCSV is most like that of Cotton leaf curl virus 72b isolate from Pakistan (98% amino acid sequence identity).  相似文献   

16.
The Middle Jurassic Tiaojishan Formation in Beipiao City, western Liaoning comprises a variety of plant fossils including leaf impressions, compressions, permineralized rhizomes, fossil wood and dispersed spores and pollen grains. Impression and compression data suggest that the flora in the Tiaojishan Formation is dominated by Bennettitales, ferns and Nilssoniales, followed by ginkgophytes; conifers and sphenopsids are less common. Abundant permineralized rhizomes are referable to diverse taxa within fern families such as Osmundaceae and Cyatheaceae. Abundant and upright fossil stumps are common in the Tiaojishan Formation. They are well preserved with distinct growth rings and are predominatly conifers. The floristic signature of the Tiaojishan Formation indicates that subtropical to temperate warm and humid climates prevailed during the late Middle Jurassic in the Beipiao area. Growth ring pattern analysis of the fossil conifer wood demonstrates a consistent and distinct seasonal climate during this interval. The biodiversity of the remarkable Tiaojishan flora provides essential evidence for understanding the vegetation, palaeoclimate and environmental evolution of western Liaoning during the Middle to Late Jurassic.  相似文献   

17.
The Middle Jurassic Tiaojishan Formation in Beipiao City, western Liaoning comprises a variety of plant fossils including leaf impressions, compressions, permineralized rhizomes, fossil wood and dispersed spores and pollen grains. Impression and compression data suggest that the flora in the Tiaojishan Formation is dominated by Bennettitales, ferns and Nilssoniales, followed by ginkgophytes; conifers and sphenopsids are less common. Abundant permineralized rhizomes are referable to diverse taxa within fern families such as Osmundaceae and Cyatheaceae. Abundant and upright fossil stumps are common in the Tiaojishan Formation. They are well preserved with distinct growth rings and are predominatly conifers. The floristic signature of the Tiaojishan Formation indicates that subtropical to temperate warm and humid climates prevailed during the late Middle Jurassic in the Beipiao area. Growth ring pattern analysis of the fossil conifer wood demonstrates a consistent and distinct seasonal climate during this interval. The biodiversity of the remarkable Tiaojishan flora provides essential evidence for understanding the vegetation, palaeoclimate and environmental evolution of western Liaoning during the Middle to Late Jurassic.  相似文献   

18.
Unlike animals, plants do not set aside germ cells early in development. In angiosperm species, reproduction occurs in the adult plant upon flowering. The multicellular male and female gametophytes differentiate from meiotic products within reproductive floral organs. Double fertilization is another remarkable feature of most angiosperm species. The zygote derived from fertilization of the egg cell by one of the sperm cells and the endosperm from fertilization of the central cell by the second sperm cell develop in a coordinated manner together and enclosed in the sporophytic maternal integuments, forming the seed. Understanding plant reproduction is biologically pertinent and agronomically and ecologically important. Here, we describe the known functions of histone lysine methylations in various steps of reproduction in the reference plant Arabidopsis thaliana. It is emerging that histone lysine methylation is key for understanding epigenetic regulation networks of genome function.  相似文献   

19.
在中国上海隆线隐翅虫亚族的分类研究中,共鉴定出隆线隐翅虫亚族3属共3种:赤翅隆线隐翅虫Lathrobium dignum Sharp,1874,黑纹伪隆线隐翅虫Pseudolathra lineata Herman,2003和翅斑细项隐翅虫Tetartopeus gracilentus Kraatz,1859.首次报道了赤翅隆线隐翅虫Lathrobium dignum和翅斑细项隐翅虫Tetartopeus gracilentus在上海的分布.首次给出了赤翅隆线隐翅虫Lathrobium dignum和黑纹伪隆线隐翅虫Pseudolathra lineata的雌性特征图,并对其主要雌性分类特征进行了描述.  相似文献   

20.
无肋树平藓(Homaliodendron pulchrum L.Y.PeiY.Jia)是2011年报道的新种,先前记载于中国四川、湖南和广西.发现了该种在中国贵州的新记录,并详细描述了采自贵州茂兰国家自然保护区该种的形态特征,绘制了墨线图,编制了贵州省境内树平藓属的分种检索表.  相似文献   

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