中国特有植物血水草开花物候与生殖特性

于2008年3-5月对分布在井冈山的血水草(Eomecon chionantha Hance )5个自然种群的开花物候进行了观察,运用开花振幅、相对开花强度和开花同步性等指数研究了其开花物候特征及其对该种生殖成功的影响.结果表明:血水草开花时间为3月下旬-5月上旬,种群花期历时24 ～46 d,个体平均开花持续时间为11～21 d,单花花期一般为3～5d;井冈山血水草种群的开花物候进程呈单峰曲线模式具有一个开花高峰期,表现出一种“集中开花模式”;与大多数亚热带植物一样,血水草具有较低的相对开花强度,分布频率集中在10％ ～30％.开花物候指数与生殖间的相关分析结果表明:始花时间与花期持续时间呈显著负相关,而与开花数和坐果率呈显著正相关;花期持续时间与开花数和坐果率呈显著正相关;同步性指数与始花时间、开花数、花期持续时间呈负相关.血水草“集中开花模式”是其在长期的进化过程中适应周围气候条件及生境的一种生殖保障.     

巫山淫羊藿开花物候与生殖特征

研究巫山淫羊藿(Epimedium wushanense)3个种群的开花物候进程和生殖特征,分析了不同种群中的花部特征、开花物候指数和结实率差异,以及开花物候指数对巫山淫羊藿生殖成功的影响。结果表明:巫山淫羊藿花期为3月初到4月中下旬,种群开花一般历时22～27d;单株花期(花序)约12～17d;单花花期一般为3～4d。3个种群的个体水平的开花振幅曲线呈单峰型曲线,均具有较高的开花同步指数,表现出一种集中开花式样。相关分析表明:坐果数与开花高峰期、终花期、花期持续时间和花蕾数均呈极显著正相关,但坐果数与始花期无相关关系。开花物候变异系数分析表明:3个种群中花期持续时间、单花持续时间、终花期、开花高峰期和坐果数差异极显著;总花数、开花振幅和结实率差异显著;开花同步指数和始花期无显著差异性。3个种群中除同步性指数外,其余指数的变异系数均有差异,此外,巫山淫羊藿中结实率受到距的长短的影响。表明巫山淫羊藿的开花物候和生殖特征受到微环境的影响,同时生殖特征还受到花部特征距的影响。     

濒危植物长柄双花木开花物候与生殖特性

研究了长柄双花木开花过程中花部表型的变化。连续4a对其野生种群、1a对人工种群的开花物候进行了观察,并运用相对开花强度和同步性等开花物候指数分析了开花物候对其生殖的影响。结果如下：长柄双花木开花时间为9月上、中旬至11月中、下旬;单花花期一般为6～7d,单花依其形态和散粉特征可以分为4个时期：散粉前期、散粉初期、散粉盛期和凋谢期。个体开花持续时间49～55d,种群花期历时63～71d。种群内不同年度间开花物候指数没有显著差异,而种群间则存在显著差异,野生种群开花进程为渐进式单峰曲线。人工种群则为“钟”形曲线,二者均属于“集中开花模式”。长柄双花木具有2个相对开花强度的分异趋势,这种分异趋势具有进化意义。开花物候指数与生殖间的相关分析表明,始花时间与开花数量、座果率及花期长度之间均具显著负相关关系,而开花数量与花期长度之间则呈显著正相关,但均为线性相关。长柄双花木开花物候在种群间的差异和种群内年度间的相似性说明,其开花时间可能是由与其相关的复杂的微生境特征和(或)由其遗传因子决定的,同时也反映了种群间的遗传分异和种群内个体间的遗传一致性。作为一种濒危物种,长柄双花木在这种环境的选择压力之下,形成了“大量、集中开放的花”的开花模式,吸引到更多的传粉者的访问,从而达到生殖成功。     

准噶尔无叶豆的开花物候与生殖特征

 为了研究沙漠稀有植物准噶尔无叶豆(Eremosparton songoricum)的开花物候特征及其对生殖成功的影响, 2005和2006年连续两年对其自然种群的开花物候和开花过程中的花部表型变化进行了观察, 并运用相对开花振幅、开花强度和开花同步性等开花物候指数研究了开花物候特征。结果表明: 准噶尔无叶豆在5月下旬至6月中下旬开花, 其种群、个体、花序和单花的花期分别历时26~29 d、8~10 d、5~7 d和2~3 d。单花开花进程依其形态和散粉特征可分为散粉前期、散粉初期、散粉盛期和凋谢期4个时期。其个体水平的开花物候进程(开花振幅曲线)呈渐进式单峰曲线, 具有很高的开花同步指数, 表现出一种集中开花的模式。开花物候指数与座果数之间的相关分析结果表明, 始花日期与花期持续时间存在负相关关系, 而与开花数和座果数存在正相关关系; 花期持续时间与开花数和座果数存在显著正相关关系。准噶尔无叶豆个体开花物候在很大程度上是由其遗传因子决定的, 而开花物候在年度间的变异, 可能是由于荒漠气候的差异(主要是水分和温度的差异)所引起的。作为沙漠窄域分布特有种, 准噶尔无叶豆在环境和人为干扰的双重选择压力下, 为了吸引更多的传粉者访问而达到生殖成功, 形成了大量集中开花的模式。     

荒漠孑遗植物裸果木的开花物候特征

2014年和2015年连续2年对哈密和乌恰裸果木(Gymnocarpos przewalskii)自然种群的开花物候特征进行野外定点观测,并运用相对开花振幅、开花强度和开花同步性等参数对其开花物候特征进行分析。结果表明,2个种群每年均开1次花,4月下旬到5月上旬进入始花期,开花进程基本相似,均呈单峰曲线,具有较高的开花同步性,呈现"集中大量"开花模式;在个体水平上,始花期、终花期在种群和年份间略有差异;单花持续时间在年际间是稳定的,但在种群间有所不同,即乌恰种群的单花持续时间略长于哈密种群;不同裸果木种群的开花数与结籽数间均呈极显著正相关,开花同步性指数与相对开花强度间呈显著负相关;乌恰种群的始花期与开花数间呈负相关。裸果木个体开花振幅、开花同步指数及开花模式在种群和年份间的相似性很大程度上是由其在长期的地理变迁中形成的遗传特性决定的,而始花期和开花持续时间等开花物候特征的差异主要是由环境和气象因子(海拔、气温、降水及光照)差异造成。研究结果对于探讨该属植物的繁殖生物学特性及其保护具有重要意义。     

金城山柔毛淫羊藿的开花物候与生殖特性

采用实地观测的方法,对南充市金城山三个不同生境中柔毛淫羊藿的开花物候特征及其生殖特性进行了研究。结果表明:柔毛淫羊藿花期为3月上旬至4月上旬,其种群、个体、花序和单花的花期分别历时30~41、22~34、9~18和4~8 d。三个生境中柔毛淫羊藿种群的开花物候进程基本相同,均呈单峰集中开花式样,因而能够吸引更多的传粉者访问而达到生殖成功。开花物候指数与坐果数之间的相关分析结果表明,坐果数与始花日期存在显著的负相关关系,与花期持续时间和开花数均呈极显著的正相关关系。揭示了药用植物柔毛淫羊藿的开花物候特征与生殖特性。     

大花百子莲的开花物候与生殖特性

连续2年对引种植物大花百子莲在中国上海市人工种群的开花物候、结实情况进行观测记录,从不同水平分析了大花百子莲的开花物候对其生殖的影响。结果显示:（1）大花百子莲在引种地的开花时间为6月初至7月末;种群花期历时40 d左右,单株花期在14～31 d波动,单花寿命主要为2～3 d;2年的开花振幅平均在6朵·株^-1·d^-1左右,花朵开放百分率值在3.69%~4.87%左右,平均开花式样为11~17朵。（2）大花百子莲种群内2007年比2008年的各项开花物候指标均提前6～9 d;种群开花进程为渐进式的双峰曲线;种群花期重叠时间较长,2年的平均开花同步指数分别为0.663、0.695;植株个体相对开花强度主要分布频度为50%～70%。（3）开花物候指数与座果率的相关分析表明,始花时间与开花数目、座果数、花期长度呈显著负相关关系,开花数目与座果数、花期长度以及花期长度与座果数均呈显著正相关关系,同一花序内单花所发育成果实的数量与单花开放时间呈极显著负相关关系。研究表明,大花百子莲始花时间早的植株比始花时间晚的植株花期更长,开花数目多的植株比开花数目少的植株花期更长,花期长的植株比花期短的植株座果率更高;而且在同一花序上,越早开放的单花其结实的可能性越大。作为引种植物,大花百子莲开花物候年度间具有相似性,说明其在引种地可以适应环境压力,形成稳定的开花时间与开花模式;较长的花期重叠和大量的开花数目可以吸引较多的传粉者访问,为其生殖成功奠定了良好基础。     

多枝柽柳春夏两季开花物候特征与生殖特性

为了研究多枝柽柳的两季开花物候特征与生殖特性,对分布于古尔班通古特沙漠南缘莫索湾荒漠区的多枝柽柳自然种群各水平的开花物候指数、开花过程中的花部特征变化和结实特性进行了观察和统计。结果表明:(1)多枝柽柳春花期为5月下旬至6月上旬,表现为"集中开花模式",夏花期为6月中旬至9月上旬,表现为"持续开花模式"。(2)多枝柽柳春、夏花期的群体、个体、花序和单花水平的花期持续时间分别为14d、10d、3d、1d和85d、77d、2d、1d。(3)花序水平上夏花期始花日期、开花持续时间、开花数和座果数两两之间均存在显著相关关系。(4)两季花期间单花水平的开花进程与形态结构没有明显差异。(5)春花期的结实率显著高于夏花期,但两季花期结籽率差异不显著。(6)春花期昆虫访花次数显著高于夏花期。(7)两季花期的花粉活力没有明显差异,春花期的柱头可授性持续时间比夏花期长。研究认为,古尔班通古特沙漠南缘莫索湾荒漠区的生境条件恶劣,多枝柽柳特殊的春、夏两季开花结实特性在一定程度上提高了其生殖成功的可能性,是对特殊生境的适应性表现。     

短命植物角茴香的开花物候与生殖特征

为了研究角茴香的开花物候特征及其对生殖成功的影响,于2015年对其自然种群各水平的开花物候指数、开花过程中的花部特征变化和结实特性进行了观察和统计。结果表明：（1）角茴香种群花期为4月下旬至5月下旬,种群水平的花期持续时间为36 d。（2）单花具有独特的花瓣结构,其内层花瓣由白色的侧裂片和黄色的兜状中裂片构成,中裂片是角茴香植物花粉二次呈现的关键功能器官;开花进程依其外层花瓣开裂大小可分为4个阶段,即外层花瓣顶端未张口、外层花瓣顶端张口5~7 mm、外层花瓣顶端张口12~14 mm和外层花瓣顶端张口3~5 mm。（3）花序水平的开花振幅曲线呈渐进式单峰曲线,开花同步指数为0.748,个体水平表现出较高的相对开花强度,其分布频度的偏斜率为0.45,主要频度范围分别集中在20%~30%和50%~70%之间。（4）花序水平的始花日期与花期持续时间存在显著负相关关系,开花数与座果数存在显著正相关关系。（5）自然状态下,角茴香结实率和结籽率分别是82.7%±0.1%和93.6%±0.8%。角茴香开花强度分布频度上出现的高、低强度的分异趋势是吸引传粉者、促进结实的有效生殖对策。     

西藏高原高寒植物长鞭红景天生殖特征成功及影响因子

为了探索高寒植物长鞭红景天(Rhodiola fastigiata)濒危的生殖生态学机理,寻找保护和恢复该物种的有效途径,对其繁育系统、开花物候特征、生殖过程(开花、结实、种子产量和发育)及其影响生殖成功的主要因子进行调查分析。结果表明:长鞭红景天包括两性植株和雌性植株两种类型,其中两性植株仅执行雄性功能,种群繁殖为异交,属风媒传粉方式。种群花期出现在1a中降雨和气温较高的季节,6月下旬开始开花,7月下旬结束,时间30d左右。单株开花动态呈现单峰和双峰曲线两种模式,两性植株花期(9.29d)大于雌性植株花期(7.06d),并先于雌性植株开放,但雌性植株开花的高峰期比两性花早。从花蕾到开花,雌性单株有16%—25%的花蕾损失;开花到结实,单株36%—57%的花败育;至种子成熟,共有84%—94%的胚珠损失,仅6%—16%的胚珠发育成种子。雌性单株平均种子产量估计值约为285粒,说明长鞭红景天生殖潜力较大。人工条件下种子发芽率为93.6%,可见种子质量不是导致其濒危的原因,花粉限制和种子产量可能是影响生殖成功的主要因素。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

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.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

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.     

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.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

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.