雄全异株植物瘿椒树（省沽油科）的传粉生物学

从开花动态、传粉昆虫、花的形态结构、繁育系统、花粉活力和柱头可授性等方面研究了我国特有珍稀植物瘿椒树（Tapiscia sinensis Oliv.）的传粉生物学特性。瘿椒树是典型的雄全异株植物,两性花中含有功能性花粉,且自交亲和,但雄花花粉活力和萌发力是两性花的10倍以上。雄株和两性植株具有相同开花物候期,花期均为5月下旬至6月上旬,单花期为4-5天,雄花和两性花的5枚花药开裂的不同步性明显延长了散粉时间。两性花雌蕊先熟,柱头可授性较长。具有适应风媒和虫媒传粉的花部特征。传粉昆虫主要为蜜蜂科（Apidae）和食蚜蝇科（Syrphidae）昆虫,访花高峰期为8：30-10：30。维持瘿椒树雄全异株的可能机制是：雄株总体上增加了异交花粉的数量和质量;两性花的雄蕊为该物种提供了繁殖保障,同时为传粉者提供了报酬。     

雄全异株植物瘿椒树(省沽油科)的传粉生物学

从开花动态、传粉昆虫、花的形态结构、繁育系统、花粉活力和柱头可授性等方面研究了我国特有珍稀植物瘿椒树(Tapiscia sinensis Oliv.)的传粉生物学特性。瘿椒树是典型的雄全异株植物,两性花中含有功能性花粉,且自交亲和,但雄花花粉活力和萌发力是两性花的10倍以上。雄株和两性植株具有相同开花物候期,花期均为5月下旬至6月上旬,单花期为4-5天,雄花和两性花的5枚花药开裂的不同步性明显延长了散粉时间。两性花雌蕊先熟,柱头可授性较长。具有适应风媒和虫媒传粉的花部特征。传粉昆虫主要为蜜蜂科(Apidae)和食蚜蝇科(Syrphidae)昆虫,访花高峰期为8:30-10:30。维持瘿椒树雄全异株的可能机制是:雄株总体上增加了异交花粉的数量和质量;两性花的雄蕊为该物种提供了繁殖保障,同时为传粉者提供了报酬。     

澜沧舞花姜繁殖生物学特性及其进化意义探讨

 舞花姜属（Globba）植物具有多样的繁殖策略。分布于西双版纳的澜沧舞花姜（Globba lancangensis）自然条件下既能结实,同时又能在花序下部产生珠芽。通过对澜沧舞花姜的花部性状、花粉活力、传粉昆虫的访花行为、结实状况、珠芽产量等多方面的观测,初步了解了澜沧舞花姜的繁殖生物学特性。结果表明,澜沧舞花姜具有雄花及两性花同株的性表达特征。雄花及两性花的花粉在中午12∶00以前活力很高,之后雄花的花粉活力急剧下降,而两性花的花粉到16∶00仍有萌发能力。澜沧舞花姜在花序上产生雄花及两性花,每个花序每天仅开少量的花,其中50%的时间仅开雄花或两性花,在整个种群中形成了一定程度的暂时性的雄花两性花异株现象,从而增加了异交的可能性。澜沧舞花姜雄花的存在为P/O低的两性花提供了花粉补贴,这使得它可以通过调节雄花与两性花比例来调节种群的P/O,从而保证一定的结实能力。人工自交与异交下结果率没有差异,但自交结实率显著低于异交结实率,表明澜沧舞花姜有明显的自交不亲和现象。排蜂（Megapis dorstata）和黄绿彩带蜂（Nomia strigata）是澜沧舞花姜的主要访花昆虫,其中排蜂是它的有效传粉昆虫。澜沧舞花姜可能通过雄花两性花同株与自交不亲和相结合来促进异交。     

峨眉拟单性木兰的开花生物学特性与繁育系统

为阐明峨眉拟单性木兰(Parakmeria omeiensis)在自然条件结实率低的原因和确定最佳人工授粉时期,该文通过观察峨眉拟单性木兰的开花动态,采用杂交指数估算、花粉胚珠比、花粉活力及柱头活性检测、人工授粉试验等方法对其繁育系统进行了研究。结果表明:(1)植物园保育的峨眉拟单性木兰花期在4月底到5月中下旬,持续17～23 d,雄株始花期比雌株早3～4 d,但两者花期可遇。(2)两性花经检测雄蕊败育,实为功能上的雌性,部分雄株个体的雄花上残留1～2个心皮,其性别分化是通过雌、雄蕊选择性败育形成的,为隐性雌雄异株(cryptic dioecy)。(3)雄花、两性花开放经历佛焰苞开裂、花被片开裂、展开、闭合、二次开放、凋落6个阶段,历时4 d。(4)雄花初次展开时花粉活力最高,达92.8%,开花2 d后活力显著下降;两性花柱头在花被片展开期可授性最强,盛开后柱头部分可授。(5)杂交指数为5,P/O比为2.14×10~4。(6)套袋试验表明,峨眉拟单性木兰不能进行自花传粉,人工异花授粉的结实率和出种数显著高于自然授粉,且不存在无融合生殖。这说明峨眉拟单性木兰繁育系统为专性异交,传粉过程需要传粉媒介,自然条件下结实率低,主要是受传粉昆虫和柱头可授期短的限制。     

臭椿花器官分化的初步研究

利用扫描电镜(SEM)和光镜(LM)对臭椿花序及花器官的分化和发育进行了初步研究,表明:1)臭椿花器官分化于当年的4月初,为圆锥花序;2)分化顺序为花萼原基、花冠原基、雄蕊原基和雌蕊原基。5个萼片原基的发生不同步,并且呈螺旋状发生;5个花瓣原基几乎同步发生且其生长要比雄蕊原基缓慢;雄蕊10枚,两轮排列,每轮5个原基的分化基本是同步的;雌蕊5,其分化速度较快;3)在两性花植株中,5个心皮顶端粘合形成柱头和花柱,而在雄株中,5个心皮退化,只有雄蕊原基分化出花药和花丝。本研究着重观察了臭椿中雄花及两性花发育的过程中两性花向单性花的转变。结果表明,臭椿两性花及单性花的形成在花器官的各原基上是一致的(尽管时间上有差异),雌雄蕊原基同时出现在每一个花器官分化过程中,但是,可育性结构部分的形成取决于其原基是否分化成所应有的结构:雄蕊原基分化形成花药与花丝,雌蕊原基分化形成花柱、柱头和子房。臭椿单性花的形成是由于两性花中雌蕊原基的退化所造成,其机理有待于进一步研究。     

喜树开花特性及繁育系统的研究

定位观测了喜树(Camptotheca acuminata Decne)花部构造、开花特性,用杂交指数(OCI)、花粉/胚珠比(P/O)、去雄、套袋、人工授粉等方法测定了喜树的繁育系统.结果表明:喜树花序为由4～6个头状花序组成的聚伞花序,聚伞花序上部的头状花序由两性花组成,下部的花序由雄花组成,两性花雌雄蕊发育正常,雄蕊10枚,雌蕊1枚,下位子房,一室,倒生胚珠;雄花雄蕊发育正常,雌蕊不发育.自然条件下,同一头状花序散粉后2 d,花粉活力最高;两性花在柱头外翻后3～4 d,柱头可受性最强,第6天失去可受性.喜树两性花为半同步雌雄蕊异熟类型,每个头状花序的所有小花同步开放,雄蕊先成熟,表现为雄性时期,雄蕊脱落后,雌蕊成熟,表现为雌性时期,上一级头状花序雌蕊成熟期与下一级头状花序雄蕊成熟期重合.繁育系统检测结果为部分自交和异交,需要传粉者活动才能完成授粉过程.     

刺山柑雄全同株性系统的适应意义

对分布于新疆北部干旱荒漠区的刺山柑Capparisspinosa性系统进行了研究.结果表明:(1)该物种具有典型的雄全同株性系统.雄花和两性花的雄蕊均正常发育,且有长短之分;两性花的雌蕊发育正常,而雄花的雌蕊败育,只行使雄性功能.(2)居群间每天开放的雄花和两性花比率、两性花的长短雄蕊数及雄花短雄蕊的花丝与花药长等存在极显著差异(P<0.01),但花器官生物量没有显著差异(P>0.05).(3)单花花期为15-16 h,每天18:00时左右开始开放,有强烈的气味和花蜜产生.植株每天产生的雄花和两性花数是随机的,可形成短时的雄花与两性花异株,但居群内雄花数比两性花数多.(4)三个居群两性花的P/O值分别为1.57×104、1.65×104和1.71×104.居群内雄花和两性花的花粉数及长、短雄蕊花药的花粉数均无显著差异(P>0.05),居群间雄花和两性花的花粉数、两性花的胚珠数及P/O值差异也不显著(P>0.05).(5)各居群雄花和两性花长短雄蕊的花粉活力动态变化曲线相似,花粉寿命为18-20 h,两性花雌蕊柱头的可授期为16-18h.(6)访花昆虫为膜翅目Hymenoptera和鳞翅目Lepidoptera昆虫,3个居群共有7种访花昆虫,其活动受天气影响很大.(7)两性花不存在无融合生殖现象,授自花花粉、同株异花花粉和异株异花花粉后均可结实,属于混合交配系统.刺山柑的雄全同株性系统可能是在长期与荒漠环境相适应的过程中由遗传和环境共同作用的结果.雄花的出现不仅增加了花粉数和P/O值,提高了植株的雄性适合度,同时增加了花的数量、对传粉昆虫的吸引力以及两性花柱头接受异花花粉的机会,提高了异交率和雌性适合度,保障其在荒漠极端环境中繁殖成功.     

片断化生境中濒危植物黄梅秤锤树的开花生物学、繁育系统与生殖成功的因素

 研究处于片断化生境中濒危植物的繁育系统、传粉过程及生殖成功状况, 可为评估物种的受胁迫程度及制订相应的保护和管理策略提 供重要依据。通过野外观察和人工授粉实验等方法,对片断化生境中濒危植物黄梅秤锤树(Sinojackia huangmeiensis)的开花生物学和繁育系统 进行了初步研究, 并探讨了影响其生殖成功的因素。黄梅秤锤树的总状花序上通常有两性花2～6朵, 单花花期约5～7 d, 单花花药不同步开裂 使整朵花花粉活力持续时间延长。虽然花开放过程中柱头始终高于花药, 在单花水平上可在一定程度上避免同花自交的发生, 但由于花粉活力 和柱头可授期之间有一定的重叠期, 在自然情况下, 由于外界媒介动物和风媒的作用, 不可避免地会产生同株同花和同株异花传粉。实验结果 表明, 该种不存在无融合生殖现象, 繁育类型以异交为主, 部分自交亲和且需要传粉者。主要的传粉昆虫为黑带食蚜蝇(Epistrophe balteata) 、中华蜜蜂 (Apis cerana) 和中华回条蜂(Habropoda sinensis)。黄梅秤锤树自然状态下的结实率较低(10.33%), 平均每果种子数较少(0.387 个), 这主要与传粉昆虫少、花粉传递效率低, 以及柱头上自花及同株异花花粉的落置和自交亲和性低有关。但是单株较大的开花量保证了一定 的果实和种子产量, 使居群能自然更新。部分自交亲和性可能为该物种适应生境片断化提供了一定的生殖保障及进化潜力。对该残存居群的保 护, 应着眼于加强对传粉昆虫赖以生存的自然生态系统的恢复。     

平基槭花性别分化的细胞形态学观察

平基槭为杂性花,雄花与两性花同株,本文对其花性别分化过程进行了细胞形态学观察。结果发现,在花性别分化的早期,雄花和两性花的花芽中雌、雄蕊原基均具备,只是在花芽发育到一定时期,雄花的雌蕊原基发生选择性败育,败育发生在大孢子母细胞减数分裂为4个大孢子时期。两性花的雌蕊可以正常膨大结实,雄蕊花药虽然可以形成二核花粉,但不能正常开裂,属于不育雄蕊。初步分析认为,两性花雄蕊花药不能正常开裂与花粉囊壁纤维层木质化程度低有关。     

新疆特有珍稀灌木银沙槐繁育系统研究

通过固定样地、样株的观测和室内、室外实验分析,运用杂交指数、花粉-胚珠比、花粉活力和柱头可授性观测、人工授粉和套袋实验等方法,对银沙槐自然种群的繁育系统进行了研究.结果表明：该种单花花期一般7~11 d,依据花的发育进程分为花蕾期、散粉前期、散粉期和萎蔫期4个阶段;花粉-胚珠为16243．35,杂交指数为4;结合人工授粉及结实结籽率结果,综合考虑银沙槐繁育系统属于异交型,部分自交亲和,没有无融合生殖现象存在,需要传粉者.银沙槐繁育系统以异交为主,存在与自交相适应的结构和行为.     

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.     

Molecular phylogeny of Phebalium (Rutaceae: Boronieae) and related genera based on the nrDNA regions ITS 1+2

Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.     

New species and new combinations in Peruvian Orchidaceae

seventeen new species and combinations are proposed in the generaChondrorhyncha, Cischweinfia, Cochlioda, Eloyella, Encyclia, Kefersteinia, Koellensteinia, Macroclinium, Rodriguezia, Solenidiopsis, andStenia. All new species are illustrated. A key is provided for 2-flowered species ofMacroclinium, PeruvianSigmatostalix, and PeruvianStenia. Solenidium (Solenidiopsis) peruvianum Schltr. is lectotypified.     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

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.     

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.     

安徽牯牛降的丝孢菌Ⅰ

本文报导作者采自安徽枯牛降自然保护区的18种丝孢菌,分属于5个属,其中有3个新种:牛皮冻生尾孢(Cercospora paederiicola),山鸡椒假尾饱(Pseudocercospora litseae-cubebae),鸡血藤生假尾孢(P. millettiicola)和2个中国新纪录。文中对新种进行了描述及绘图,新记录种作了简要说明。研究的标本保存在中国科学院微生物研究所真菌标本室(HMAS)。     

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields), each with four replicates (n = 16 sites). At each site we used 10 pitfall traps, baited with cattle dung, along a 100 m transect for six 3-day periods. The number of trapped specimens and species richness at the natural forest sites was higher than in all land-use systems, which did not significantly differ. Each land-use system contained, on average, 75% of the species richness of the natural forest, thereby indicating their importance for conservation. However, a two-dimensional scaling plot based on NESS indices (m = 6) indicated distinct dung beetle communities for both forest types, while agroforestry systems and annual cultures exhibited a pronounced overlap. Mean body size of dung beetles was not significantly influenced by land-use intensity. Five of the six most abundant dung beetle species were recorded in all habitats, whereas the abundance of five other species was significantly related to habitat type. Mean local abundance and number of occupied sites were closely correlated, further indicating little habitat specialisation. The low dung beetle diversity (total of 18 recorded species) may be due to the absence of larger mammals in Sulawesi during historical times, even though Sulawesi is the largest island of Wallacea. In conclusion, the dung beetle fauna of the lower montane forest zone in Central Sulawesi appears to be relatively robust to man-made habitat changes and the majority of species did not exhibit strong habitat preferences.