DISPERSAL ECOLOGY OF VANCOUVERIA (BERBERIDACEAE)

All Vancouveria species are habitual myrmecochores of the Viola odorata type. The anatropous, bitegmic seed develops an unusual elaiosome in the form of a large, empty, folded and lobed sac of epidermal tissue. The thin-walled assimilating capsule dehisces along an oblique weak zone that probably represents the suture between two fused and unequal carpels. In V. hexandra the capsule opens early to expose immature assimilating seeds. Decurved pedicels, down-turned fruits, and weak funiculi produce tachyspory. The related Epimedium, Jeffersonia, and Plagiorhegma have appendaged seeds and other possible myrmecochorous features resembling those of Vancouveria. Myrmecochory was probably established in the early or middle Tertiary period. The Vancouveria-Epimedium complex indicates that enormous plant migrations may be accomplished by means of ants.     

SEED GERMINATION ECOPHYSIOLOGY OF JEFFERSONIA DIPHYLLA,A PERENNIAL HERB OF MESIC DECIDUOUS FORESTS

Freshly-matured seeds of the mesic deciduous woodland herb Jeffersonia diphylla (L.) Pers. (Berberidaceae) have underdeveloped (ca. 0.6 mm in length) embryos and exhibit deep, simple morphophysiological dormancy (MPD). For rapid growth of the embryos at October (20/10) and November (15/6 C) temperatures in October and November, seeds must first be exposed to high (30/15 C) summer temperatures. If embryo growth is not completed in autumn, it continues during winter. However, even after 10–12 weeks at summer temperatures, embryos grew very little at 5 C, unless growth already had begun at autumn temperatures. After embryo growth has been completed, or after it has been initiated, seeds require cold stratification (5 C) to overcome dormancy. Embryos must attain a minimum length of about 1 mm before seed dormancy can be broken by cold stratification. Gibberellic acid increased the rate of embryo growth in seeds kept at 20 C, but only 1–9% of them germinated. Thus, GA substitutes for warm but not cold stratification. High summer temperatures, as well as the traditionally-used autumn and winter temperatures, should be used in germinating seeds with deep, simple MPD.     

桃儿七繁殖生物学研究

以居群为单位研究了桃儿七的繁殖生物学,指出桃儿七为适应分布区内生长季节短暂的环境条件,花各部分的形态在开花前一年就已开始分化,并形成一休眠芽,但大小孢子还尚未进行减数分裂。到了第二年春天气温回升之后,大小孢子方才进行减数分裂,并在减数分裂之后,植株通过茎基部的居间生长将花及叶带出地面。桃儿七在开花时先花后叶。花在露出土面的第二、三天随即开放。虽然桃儿七具有一系列适应干虫煤传粉的形态结构和生物学特征,但同时也具有许多和自花授粉有关的适应机制。桃儿七在开花习性及花部形态上常表现出多态。在自然状况下,桃儿七是一种以自花授粉为主的植物,它的有性生殖良好,每株性成熟植株平均可产生60粒左右的种子,多者可达180粒。由种子萌发长成的植株大约需要5－6年的时间方才性成熟。在一般条件下,桃儿七行有性生殖,但在环境条件良好时,也可通过根茎来进行营养繁殖。桃儿七为二倍体,12条染色体组成6个联锁群,在减数分裂时,交叉发生较少。桃儿七具有较大当前适合度,亦具有一定的进化灵活度。     

荒漠沙蜥繁殖生态研究

荒漠沙蜥（Ｐｈｒｙｎｏｃｅｐｈａｌｕｓｐｒｚｅｗａｌｓｋｉｉ）１年繁殖１次,有明显的季节性周期。４月初出蛰时雄性精巢已相当发育,５月其重量和体积最大,６月变小,进入精子发生的晚期,７月降到最小,８月开始回升,１０月中旬入蛰时已接近春季出蛰时水平。１年内仅７月精巢中无精子。雌性出蛰后卵细胞开始发育,４月下旬进入成熟期,６月达高峰,７月下降,８月进入休止期。每雌年产卵１～３枚或１～４枚,平均１．８３（ｎ＝４８,１９８７）和２．１７（ｎ＝４８,１９９３）。特定体长组的生殖率是影响种群年平均生殖率的主要因素。生殖周期与光周期相符,光周期是影响荒漠沙蜥生殖周期的主要气候因子。     

苦草繁殖生态学研究

通过太湖野外调查、室内培养、种子与块茎萌发及幼苗生长试验,对太湖苦草(Vallisneria natans)种群的繁殖生态特征进行了研究。结果显示:1)苦草分配于有性繁殖部分的生物量较无性的大,分别占总生物量的25.0%±13.8%和10.1%±7.0%。雌花数与座果率平均分别为22.9±13.8朵·株^-1和73.3%±17.9%。雄株可以产生11~33个佛焰苞,每个佛焰苞内平均含有364±38朵雄花,每个雄花产生的花粉为128~184粒。每个果实内种子丰富,多达150~360粒,估算太湖苦草种群立地种子量可达1.68×10⁴~1.01×10⁶个·m^-2。但每年种群主要来自地下块茎和匍匐茎,水深、风浪等可能是种子苗难以在湖泊中定植成功的主要因素。2)苦草的块茎数量较大,平均90~226个·m^-2,是种群发展的强大物质基础。3)温度、光照、基质及种子保存方式与时间长短对种子发芽率均有较大影响。10 ℃时种子发芽率较低,仅8.35%±1.89%;20 ℃时发芽率较高,为56.73%±6.42%;30 ℃时发芽率有所降低,为43.55%±4.34%。种子发芽对光照有一定要求,20 ℃、无光条件下,种子发芽率下降63.6%。在没有湖泥为基质的情况下,发芽率下降36.5%。此外,随干燥保存时间增加,种子发芽率下降。4)块茎发芽对光照需求不大,但温度对块茎的发芽率有较大影响,10 ℃时发芽率为20.3%±5.7%,20 ℃时较高,达90.2%±12.6%,30 ℃时发芽率降低至60.4%±7.6%。5)光照对幼苗生长有一定影响。有光照的幼苗伸长生长比无光条件下慢,但生物量积累较大,有光的苗生长速度平均为0.56~0.70 cm·d^-1,无光的为0.86~0.96 cm·d^-1。试验结果还显示,苦草的块茎苗初期的伸长生长主要依赖于基部的根茎生长。6)根据研究结果认为,在湖泊中恢复苦草种群应主要利用地下块茎,种子只适用于相对静止的浅水池塘种植。     

REPRODUCTIVE ECOLOGY AND BIOGEOGRAPHY OF INDO-WEST PACIFIC ANGELFISHES (PISCES: POMACANTHIDAE)

Analysis of the relationships between duration of the pelagic larval stage (as indicated by otolith microstructure), adult size, and the extent of geographic distribution for Indo-West Pacific angelfishes (Pomacanthidae) indicates that neither adult size nor larval duration significantly predicts extent of distribution, either individually or jointly in a multiple regression. These results are robust for both the family as a whole and the genus best represented in our data (Centropyge). If larval duration and adult size do have an effect, it is only jointly and at the genus level. However, larval duration and adult size do correlate significantly and negatively with one another. The operational factor seems to be egg size, which correlates positively with adult size, and negatively with duration of the pelagic larval stage. Similar correlations are evident in both marine invertebrates and at least some other coral-reef fishes, suggesting they are of widespread significance. The limited ability of either reproductive parameter to predict extent of species distribution indicates, first, that even in a group as morphologically conservative as the Indo-West Pacific pomacanthids, neither a two-fold difference between species in larval duration nor a two order of magnitude difference in female fecundity markedly affects extant distributions; and secondly, that either undescribed biological factors or historical constraints are of paramount importance. Available evidence suggests that dispersal abilities of most coral reef fishes, in fact, may be limited, despite the nearly universal occurrence of a pelagic stage in development.     

菜花原矛头蝮的分布及其在山西繁殖生态的观察

菜花原矛头蝮(Ｐｒｏｔｏｂｏｔｈｒｏｐｓｊｅｒｄｏｎｉｉ[Ｇ櫣ｎｔｈｅｒ,1875])是我国主要毒蛇之一,隶蝰科(Ｖｉｐｅｒｉｄａｅ),蝮亚科(Ｃｒｏｔａｌｉｎａｅ),原矛头蝮属。它是山西省三种毒蛇之一,有一定危害,也具有一定的经济价值。现对其分布和繁殖生态报道如下。ＡｌｂｅｒｔＧ櫣ｎｔｈｅｒ(1875)依据印度东北部Ａｓｓａｍ邦Ｋｈａｓｓｙａ(=ＫｈａｓｉＨｉｌｌｓ)标本描述Ｔｒｉｍｅｒｅｓｕｒｕｓｊｅｒｄｏｎｉｉ,我国称菜花烙铁头蛇。稍后(1889),同一作者又依据我国湖北宜昌标本描述Ｔｒｉｍｅｒｅｓｕｒｕｓｘａｎｔｈｏｍｅ…     

多疣壁虎的繁殖生态研究

多疣壁虎(Gekko japonicus)是一种季节性繁殖的爬行动物,性腺活动状态在不同的季节有显著的差异。成年雌体在冬眠结束后的4月初卵巢开始增大,野外产卵期一般在5月下旬至8月上旬。一个繁殖期平均产卵1.8窝,每窝恒定两枚。每窝卵重与个体大小之间存在着显著的正相关,大个体的产卵频率亦较高。雄体的精巢重量和大小的月间差异显著,但变化不及雌体的卵巢显著。雌体的繁殖期可以被环境温度所改变。繁殖效力用每窝卵干、湿重及能值与雌体干、湿重及能值的比值估算。     

THE DEVELOPMENT OF THE FEMALE GAMETOPHYTE OF EPIPACTIS (ORCHIDACEAE) AND ITS INFERENCE FOR REPRODUCTIVE ECOLOGY

The development of the female gametophytes of Epipactis atrorubens, E. helleborine, and E. palustris have been investigated using confocal scanning laser microscopy. These species have T-tetrads and eight-nucleate female gametophytes in common. The development of the female gametophyte is monosporic in accordance with the Polygonum type. Furthermore, the outer integument grows slowly and reaches to the middle of the inner integument, when the female gametophyte is mature. In the first two species, T-tetrads develop prior to anthesis, which may be correlated with autogamy. The development of the female gametophyte of E. palustris appears to be similar in plants from different localities.     

贵州疣螈繁殖生态的研究

贵州疣螈（Tylototritonkweichowensis）是一年繁殖一次的有尾两栖动物。繁殖期肥满度、肝脏系数、脂肪系数、性腺成熟系数、性腺体积均具一定的生物学意义。繁殖期一般为5月上旬至7月上旬,窝卵数平均121．5±7．81枚,孵化期21．6天,孵化率44．33％。每窝印数与雌体头体长成正相关。幼体不同日龄的形态特征变化明显。其全长的Logistic生长方程为：     

REPRODUCTIVE ECOLOGY OF CARYA (JUGLANDACEAE): PHENOLOGY,POLLINATION, AND BREEDING SYSTEM OF TWO SYMPATRIC TREE SPECIES

Observations and experiments on both shagbark (Carya ovata; 2n = 32) and mockernut (C. tomentosa; 2n = 64) hickories in a New Jersey forest were performed over a 2-year period to determine the mechanisms operating both to maintain reproductive fidelity and to regulate fruit initiation. Phenological observations indicated significant differences between the species for almost all vegetative and reproductive characters examined; however, a large amount of overlap was also observed. Pollination experiments indicated that pollen limitation is not a significant factor in reducing fruit set in these anemophilous species. Pollen-ovule ratios ranged from 1 to 25 × 10⁶. Pollen was 80–90% viable at time of shedding. The large surface area of vegetative structures (e.g., leaves) at the time of pollination may retard the flow of pollen into and out of the canopy and thus increase self-pollination. A full diallel cross, replicated 5 times, was made among 8 trees (4 trees of each species) to characterize combining ability and compatibility relationships. All trees were found to be both geitonogamous and xenogamous to varying degrees. A high frequency of putative interploidal cross-compatibility was also observed. Fruits from these interspecific crosses were found to be germinable. Observations on individual trees suggested that dichogamy may help to reduce selfing and promote outcrossing in this breeding system. While most trees exhibited a temporal separation of genders, the trait was found to be quite plastic (i.e., trees switched between protogyny and protandry between years). Pistillate flowers were receptive for all trees within a species during the same general time period; however, pollen shedding varied considerably among trees and between years. Both species appear to be utilizing a broad array of mechanisms in order to maintain reproductive fidelity and adequate fruit set.     

海南十大功劳属一新种

海南十大功劳属一新种胡启明,李泽贤,邢福武（中国科学院华南植物研究所,广州５１０６５０）关键词海南十大功劳ＡＮＥＷＳＰＥＣＩＥＳＯＦＭＡＨＯＮＩＡ（ＢＥＲＢＥＲＩＤＡＣＥＡＥ）ＦＲＯＭＨＡＩＮＡＮ￥ＨｕＣｈｉｍｉｎｇ;ＬｉＺｅｘｉａｎａｎｄＸｉｎｇＦ...     

通过交配系统了解植物生殖生态学

进行有性生殖的植物可以通过两个途径——花粉或者种子——来传递它们的基因 (即适合度 )。雌雄同体的植物不仅可以依靠种子生产获得雌性适合度 ,而且还可以依靠花粉途径获得雄性适合度。从种群角度看 ,这两个途径完全是均等的 ,在重要性上并没有什么差别。每个二倍体生物都只有一个父亲、一个母亲。对于一个繁育种群来说 ,通过种子途径传递的基因与通过花粉途径传递的基因在数量上必然是相等的 ,虽然不同个体之间可能存在着这样或那样的差别。早期的植物学家几乎把注意力全部集中在种子生产上 ,基本上忽略了植物个体的雄性适合度组分 ,似乎…     

THE ECOLOGY OF THE HONG KONG LIMPETS CELLANA GRATA (GOULD 1859) AND PATELLOIDA PYGMAEA (DUNKER 1860): REPRODUCTIVE BIOLOGY

Cellana grata is large, relatively long lived (3 years), withone winter breeding season each year which can be correlatedwith major seasonal climatic and hydro-logical events, e.g.,winter reduction in temperature and higher seas. C. grata ischaracterised by a relatively low value of mean annual reproductiveeffort (males: 23%; females: 18%). Patelloida pygmaea is small,short lived (1 year), with one spring breeding season each yearand devotes a large proportion of metabolic energy for reproduction.P. pygmaea showed a higher value of mean annual reproductiveeffort (males: 46%; females: 31%) than C. grata. Mature gonads of Cellana grata first appeared in June and itreached a peak maturity (100%) in September, remaining so untilDecember, i.e., the maturation of the gonads coincided withincreasing water temperatures, with spawning associated witha decrease in water temperature. Gonadal development by Patelloidapygmaea began in either July or August and reached a peak inDecember, remaining so until a major peak in spawning took placebetween April and May, i.e., gonad maturation coincided witha decline in water temperature, with spawning following thesubsequent increase. Limpet gonadal cycles are likely gearedto temperature and food supply. Spawning occurred between Novemberand December, when wave heights are typically 1 m higher thanin summer. (Received 1 December 1992; accepted 25 June 1993)     

REPRODUCTIVE FEATURES OF DENTARIA LACINIATA AND D. DIPHYLLA (CRUCIFERAE), AND THE IMPLICATIONS IN THE TAXONOMY OF THE EASTERN NORTH AMERICAN DENTARIA COMPLEX

Reproductive features including ovule development, megasporogenesis, megagametogenesis, microsporogenesis, microgametogenesis, pollen tube growth, embryogeny, and natural seed germination were studied in a single population each of Dentaria laciniata Muhl. ex. Willd. and D. diphylla Michx. to test for possible agamospermy. The population of D. laciniata studied is sexual. The archesporial cell functions directly as the megasporocyte. It undergoes two meiotic divisions, but the micropylar cell of the dyad fails to undergo meiosis II, and a linear triplet of three cells is formed. The chalazal megaspore divides to form an eight-nucleate, seven-celled megagametophyte of the Polygonum type. Simultaneous cytokinesis follows the second meiotic division of the microsporocyte yielding a tetrahedral tetrad of microspores. A three-celled pollen grain is formed prior to anther dehiscence. Following apparent fertilization, the Capsella-variation of the Onagrad type of embryogeny results in a conduplicate embryo. Endosperm is initially nuclear, but eventually becomes cellular. Seeds readily germinate in nature. Similar events are documented in one population of D. diphylla up to the organization of the embryo-sac, which disintegrates before cellularization. These reproductive events and other data indicate that the eastern North American species of Dentaria may form a sexual polyploid complex with some sexual populations and some sterile ones.