我国万寿竹属新植物

<正> 万寿竹属Disporum是百合科中一个中等大小的属,约20种,主要分布于北美洲温带、喜马拉雅地区、爪哇、日本和中国。我国有10种,分布于全国各地。 作者在整理云南万寿竹属植物时,发现万寿竹属在我国一新分布和1新种,现报道。     

REPRODUCTIVE BIOLOGY OF ERYTHRONIUM GRANDIFLORUM VARIETIES GRANDIFLORUM AND CANDIDUM (LILIACEAE)

This four-year (1982–1986) study compared the pollination biology and cytology of a relatively rare taxon, Erythronium grandiflorum Pursh var. candidum (Piper) Abrams, with that of a geographically widespread sister taxon, E. grandiflorum var. grandiflorum, in the Pacific Northwest. Breeding studies were used to study the reproductive systems of the taxa, to test for interfertility between them, and to seek abnormalities in the breeding system of the rare taxon that might account for its relative rarity. Chromosomes were counted in both taxa and in hybrids from artificial crosses. Ranges of the two taxa were determined from field studies and herbarium specimens. Although the ranges of the taxa overlap in part, populations are usually allopatric. Phenological factors are probably minor in preventing cross-pollination between the taxa. Both taxa are protogynous obligate outcrossers pollinated by bees. Seed production apparently is not pollinator-limited. The two taxa are interfertile only when individuals from allopatric populations are artificially crossed, and thus should be considered two biological species. When the taxa overlap in floral phenology in sympatric populations, they exhibit reciprocal incompatibility. Such incompatibility between closely related perennial species is unusual. It may have arisen via natural selection in mixed populations. Alternatively, if populations of each taxon vary with regard to their incompatibility alleles, they may have acquired their fertility barriers by chance before populations of the two taxa came into contact with each other.     

两种珍稀植物群落物种多度分布的核方法研究

首次提出物种多度分布的非参数核密度估计方法,介绍了此方法的构造和主要性质。珍稀濒危植物观光木群落和长苞铁杉群落的乔木层、灌木层、所有木本植物物种多度分布实例拟合结果表明,核方法能很好地描述群落物种多度分布。非参数核估计方法是群落物种多度分布模拟的一种有效方法,它丰富了物种多度分布拟合方法,为珍稀濒危植物的管理与保护提供了理论参考。     

萱草属中国特有种的细胞分类研究

对萱草属3个中国特有种,折叶萱草、西南萱草和多花萱草间的亲缘关系,不同学者有不同观点。本文试图从核型特征阐明三者的亲缘关系。折叶萱草、西南萱草和多花萱草的核型公式分别为：2n=12m+8sm+2T;2n=8m+12sm+2T和2n=12m+4sm+4st+2T。核型不对称性依次加大;三者均在T型(第11号)染色体着丝点端具有微小随体。三者染色体组分之间的欧氏距离：折叶萱草与西南萱草为0．2728;折叶萱草与多花萱草为0．4501;西南萱草与多花萱草为0.5741。以上资料表明,折叶萱草与西南萱草更为近缘,而多花萱草比前二者进化。     

长期施用稀土对小麦植株中稀土元素含量及分布的影响

在我国施用稀土时间最长的黑龙江花园农场,研究了连续１２ａ叶面喷施稀土对小麦植株及土壤中稀土元素总含量和分布模式的影响。结果表明：连续１２ａ叶施稀土没有造成土壤中元素含量及分布模式的变化;对小麦拔节始期（喷施稀土７ｄ）后叶部的影响较大,Ｌａ,Ｃｅ最明显增高,叶部稀土元素分布模式与“常乐”稀土中的相一致,与土壤中稀土元素分布模式不同,而在小麦拔节始期的根部、小麦成熟期的根、茎、叶、壳等部位稀土元素分布     

浙江百合科一新种和一新变种

本文发表了浙江百合科一新种即浙江黄精Polygonatam zhejiang X.J.Xue et H.yao,sp.nov.一新变种即紫花南玉带Asparagus oligoclonos Maxim var.Purpurasceas.     

EFFECT OF LIGHT AND WATER-STRESS ON PHOTOSYNTHESIS AND BIOMASS PRODUCTION IN BOLTONIA DECURRENS (ASTERACEAE), A THREATENED SPECIES

Boltonia decurrens (Torrey & Gray) Wood, a perennial species endemic to the Illinois River Valley, is threatened with extinction. Construction of a system of dikes along the Illinois River has altered flood patterns during the last 100 years, converting wet prairies and natural marshes to cropland. Remaining shore habitats have been modified by heavy siltation and altered flooding regimes. Boltonia decurrens is now confined to areas that are disturbed by occasional cropping, disappearing from sites after 3 to 5 years of natural succession. This study was conducted to determine the role of light and water availability upon growth and reproduction. Our data indicate that under greenhouse conditions B. decurrens requires high levels of light for optimal photosynthesis and growth, and is more sensitive to reductions in growth light level than to moderate drought-stress. This sensitivity to light regime may help explain its disappearance from disturbed areas after several years of natural succession. If B. decurrens is overtopped by fast-growing species, it could be shaded to the extent that growth and seed production would be severely affected, increasing the likelihood of its extinction.     

POLLEN MORPHOLOGY IN THE GENUS ERYTHRONIUM (LILIACEAE) AND ITS SYSTEMATIC IMPLICATIONS

Pollen morphology was examined in 40 samples from 19 species in the genus Erythronium (Liliaceae) using scanning (SEM) and transmission electron microscopy (TEM). Pollen grains are monosulcate monads, except for a plant of E. oregonum which has dyad grains. North American and European species are characterized by reticulate exine sculpture composed of various degrees of wavy muri and variably-sized lumina. The most distinctive feature of exine sculpture in the genus is exhibited by the Asian species E. japonicum, which has a unique reticulate pattern composed of striate muri and a distinctive exine structure without columellae. The distinctness of E. japonicum pollen suggests that it has specialized in isolation from species in North America and Europe.     

EFFECT OF SALINITY ON PSEUDO‐NITZSCHIA SPECIES (BACILLARIOPHYCEAE) GROWTH AND DISTRIBUTION1

Salinity varies widely in coastal areas that often have a high abundance of Pseudo‐nitzschia H. Peragallo. Pseudo‐nitzschia is abundant in Louisiana waters, and high cellular domoic acid has been observed in natural samples but no human illness has been reported. To assess the threat of amnesic shellfish poisoning (ASP), we examined the effect of salinity on Pseudo‐nitzschia occurrence in the field and growth in the laboratory with special emphasis on the salinity range where oysters are harvested (10–20 psu). In Louisiana coastal waters, Pseudo‐nitzschia spp. occurred over a salinity range of 1 to >35 psu, but they occurred more frequently at higher rather than lower salinities. Seven species were identified, including toxigenic species occurring at low salinities. In culture studies, seven clones of three species grew over a salinity range of 15 to 40 psu, some grew at salinities down to 6.25 psu, and most grew at salinities up to 45 psu. Tolerance of low salinities decreased from Pseudo‐nitzschia delicatissima (Cleve) Heiden to P. multiseries (Hasle) Hasle to P. pseudodelicatissima (Hasle) Hasle emend. Lundholm, Hasle et Moestrup. In conclusion, although Pseudo‐nitzschia was more prevalent in the field and grew better in the laboratory at higher salinities, it grew and has been observed at low salinities. Therefore, the probability of ASP from consumption of oysters harvested from the low salinity estuaries of the northern Gulf of Mexico is low but not zero; animal mortality events from toxin vectors other than oysters at higher salinity on the shelf are more likely.     

裂叶沙参分布区域和生物学生态学习性的调查

濒危植物裂叶沙参(Adenophora lobophylla Hong)已发现的天然分布区在四川西北部金川县的安宁、曾大、卡撒、马尔邦、观音桥五个乡,分布面积估计不超过5000km2,根据文献记载和50年代采集的标本分析,裂叶沙参的分布区正在缩小。裂叶沙参以有性生殖为主,在外界干挠和春旱严重的条件下也营无性生殖。在海拔2700m以下地区,裂叶沙参星散分布,生长发育不良,年龄结构老化,种群呈衰退趋势。在较为适生的海拔区间(2700-2900m),裂叶沙参生长正常,花果产量高,年龄结构合理。在海拔2900m以上地区,裂叶沙参分蘖数、花果量减少,个体寿命缩短。裂叶沙参所处群落可分为山杨、山棉花林;旱生多刺灌丛或灌丛;旱生灌草丛;和旱生草丛。裂叶沙参种群在各群落中均为伴生种,受到群落不同程度的影响。     

四川百合科吉祥草属一新种

根在簇生叶下面长出。甸旬茎粗3-5毫米,逐年延长生长,具节和鞘状鳞片。叶敖生,4-9枚,狭条形,稀披针形,长6-17(-20)厘米,宽3-5(-7)毫米,先端急尖或钝,基部渐狭成不明显的柄。花萃从叶腋抽出,平卧,长1.5-25厘米;穗状花序长2-3(-4)厘米,近于平卧,稍弯曲,具有5-7花;每花基部具有1-2苞片,卵形或卵状披针形,长610毫米,紫色或淡紫色。花被厚肉质,白色,裂片椭圆形或椭圆状扯针形,长56毫米,宽1.6-2毫米,先端近圆形,花被筒长为花被裂片的2/3;雄蕊着生于花被裂片下,与其对生,花丝长34毫米,花药淡黄色,矩圆形,长约2毫米;子房卵圆形,直径约2毫米,花柱长812毫米,柱头3浅裂。     

滇东南丫蕊花属(百合科)一新种及其生物地理学意义

报道了云南东南部金平县五台山丫蕊花属(百合科)一新种,并讨论了其生物地理学意义     

物种多度格局研究进展

物种多度格局研究始于20世纪30年代,是种群生态学和群落生态学研究的起点。物种多度格局研究主要在两个水平上进行：1）初期研究主要集中于群落水平,希望在不同群落之间发现一个共同的整体格局来描述群落的组织结构。常用模型包括几何级数、对数级数、对数正态和断棍模型,不同模型代表了不同的生态学过程。2）目前转向重视物种水平,并以物种多度的区域分布规律及其生态学机制研究为主。物种分布区多度关系有正相关、无相关和负相关3种形式。局部多度高的物种一般趋于广布,而局部多度低的物种趋于受限分布。物种多度区域分布的生态位模型预测为单峰型,还经常会出现“热点地区”;而异质种群模型预测为双峰型。物种多度的区域分布主要由环境资源特性、物种生态位和扩散过程等因素决定。3）物种多度格局的时间变化与空间变异类似,代表了这些生态学过程的时间异质性。4）物种多度格局的尺度变化经常表现出自相似性,但该规律并非一直存在,因为生物多样性由不同尺度上的不同生态学过程决定。5）多度（稀有度）是物种保护的基本依据,而群落多度模型能够指示生态学和干扰过程变化对群落结构的影响。物种多度格局的模型手段仍需改进,机制研究尚不系统,应用研究亟待扩展,对于物种多度格局的深入理解将为揭示生物多样性分布机制和有效保护提供帮助。     

云南省捕食螨种类及分布调查

1992年～1999年对云南省捕食螨种类及分布进行了系统调查,云南省捕食螨8科12属56种,其中植绥螨科有6属51种,从海拔320m～3250m地区都有分布.根据云南省捕食螨种类及其地理分布特点,将云南省捕食螨的地理分布从垂直方向分为高寒带、中暖带和亚热带3个层次,代表不同海拔、气候、耕作制度、捕食螨特点等.捕食螨种类及分布的系统调查为制定捕食螨的合理保护和利用及农林害螨类的综合治理和控制措施提供了理论依据.     

REGULATION OF NaCl IN JAUMEA CARNOSA (ASTERACEAE), A SALT MARSH SPECIES,AND ITS EFFECT ON LEAF SUCCULENCE

A salt marsh species, Jaumea carnosa, was used in hydroponic experiments to test the effects of increasing NaCl concentrations on leaf succulence and plant accumulations of K, Ca, Mg, Na and Cl. A nested experimental design was used with four salinity levels. Plants were grown in full Hoagland's solution plus different amounts of NaCl (0.0–1.2 osmoles). Leaf succulence was measured as percent water content as well as vertical elongation of mesophyll cells. There were no corresponding increases in leaf succulence with increasing concentrations of NaCl in the root zone. Plants receiving aerosol spray (40 mg/dm²/day) did not show significant increases in leaf succulence. Leaf succulence was significantly increased when the plants were removed from the NaCl solutions and placed in non-salinized Hoagland's solution. Osmotic concentrations of cell sap in leaf tissues showed significant increases as NaCl concentrations increased in the root zone. The concentrations of K, Ca and Mg were higher in plants grown without NaCl than in those grown with NaCl. The accumulations of K in the root tissues were always higher than those of the shoot tissues. Although there was a two-fold difference in NaCl concentrations at the highest levels, the concentrations of Na in the shoot tissues were relatively similar. The results of the Cl analyses of shoot tissues showed a similar pattern of regulation of uptake. This regulation of salt uptake may be important in preventing injury by limiting accumulations of salt in plant tissues when growing in soils of high osmotic potentials.     

THE INFLUENCE OF HABITAT ON THE DISTRIBUTION AND ABUNDANCE OF PEREGRINE AND LANNER FALCONS IN SOUTH AFRICA

Jenkins, A.R. 1994. The influence of habitat on the distribution and abundance of Peregrine and Lanner Falcons in South Africa. Ostrich 65: 281–290.

The distribution and abundance of Peregrine and Lanner Falcons in South Africa was compared using recorded sightings from various sources, including the Southern African Bird Atlas Project. Falcon distributions were compared with the distribution of cliffs and vegetation, to quantify differences in the habitat preferences of the two species in the breeding and the non-breeding seasons. Lanner Falcons outnumbered Peregrine Falcons in most areas by at least 10:1. Peregrine Falcons were more habitat specific than Lanner Falcons, in terms of topographic and biotic requirements. Peregrine Falcons were largely restricted to high cliff areas throughout the year and there probably were no large-scale seasonal movements within the population. The bulk of the resident Peregrine Falcon population was found in the fynbos biome, in the southwestern Cape. Outside of this area, Peregrine Falcons were concentrated in woodlands. Lanner Falcons were less dependent on high cliffs, although cliff availability was important in defining the ranges of both species. Lanner Falcons were most common in the sour grasslands in the east of the country in the breeding season, with apparent movements in the non-breeding season into the fynbos, the Nama Karoo and the southern Kalahari. Overall, Peregrine Falcons favoured relatively closed habitats and Lanner Falcons favoured relatively open habitats. The differences in the two species' habitat preferences are proximate factors influencing distribution and abundance.     

武昌东湖枝角类种类组成与数量变动的观察

枝角类是一切幼鱼以及許多经济鱼类成鱼期的良好食料。