等片藻属几个种的分类学问题研究

本文使用光学显微镜和扫描电子显微镜对等片藻属Diatoma的6个种：冬季等片藻 D·hiemale(Roth)Heib．、巨大等片藻D．maximum(Grun．)Fricke、中型等片藻D．mesodon(Ehr)Kuetz．、念珠状等片藻D．moniliforme Kuetz．、纤细等片藻D. tenue Ag.、等片藻D,vulgare Bory及其下的4个变种作了研究,并讨论了它们的分类学问题。     

中国水云科藻类的新记录

本文报道了中国分布的水云科(褐藻门)藻类3个新记录种,即束枝水云弯枝变种;笔头状水云;石鳖费氏藻。     

Flora Algale Dell'Isola Lachea (Golfo di Catania)

Abstract

Observations on the seaweeds on the Island of Lachea. — Within the frame of the research on seaweeds in the Eastern part of Sicily which is being carried out at the Botanical Department of Catania University, the AA. have undertaken a study on the seaweeds to be found on the Island of Lachea. The material has been collected from the supralittoral to the infralittoral. One hundred and thirty-five species have been identified and data about the local distribution and habitat have been given. The following species are new to Sicily: Spatoglossum solierii (Chauv.) Kuetz., Bonnemaisonia asparagoides (Woodw.) Ag., Gelidiella ramellosa (Kuetz.) Feld. et Ham., Antithamnion cruciatum (C. Ag.) Naeg. var. profundum G. Feld., Antithamnion plumula var. bebbii (Reinsch) J. Feld., Ceramium bertholdi Funk, Ceramium codii (Richards) G. Maz., Spermothamnion repens (Dillw.) K. Ros. var. flagelliferum (De Not.) Feld., Griffithsia barbata (Smith) C. Ag., Polysiphonia biformis Zan., Lophocladia lallemandi (Mont.) Schmitz; and the following species are new to Eastern Sicily: Codium difforme Kuetz., Bryopsis penicillata Kuetz., Liebmannia leveillei J. Ag., Thuretella schousboei (Thur.) Schmitz, Dudresnaya verticillata Le Jol., Amphiroa cryptharthrodia Zan., Corallina squamata Ell. et Sol., Pseudolithophyllum expansum (Phil.) Lem., Ceramium rubrum var. implexo-contortum Solier, Ptilothamnion pluma (Dillw.) Thuret, Aglaothamnion neglectum G. Feld.     

Karyological studies of three species of Cladophora (Cladophorales,Chlorophyta) from Bermuda

Abstract

Chromosome numbers for three species of Cladophora from Bermuda are presented. C. laetevirens (Dillw.) Kuetz., C. prolifera (Roth) Kuetz., and C. conferta Crouan frat. ex Schramm & Maze were found to have similar karyotypes with 1 N = 2 X = 12 chromosomes belonging to size class III (0.8–2.2 μm). Correlations between each species' karyotype and its morphology and phytogeographic affinity are discussed. Estimates of the basic genome (1 X) for these and other Cladophora species indicate that nuclear DNA content, which shows a threefold variation in the genus, occurs in discontinuous increments. These findings are discussed in relation to reports of large scale, discontinuous DNA variation in vascular plant genera.     

DIATOM ASSEMBLAGES OF STREAMS INFLUENCED BY WILDFIRE1

The Greater Yellowstone Area ecosystem experienced major wildfires in 1988, resulting in a substantial number of catchments being burned. We studied diatom assemblage structure at 14 sites over 5 years in catchments ranging from 0 to over 90% burned. Coefficients of variation for selected physical measures provided a good assessment of the degree of disturbance experienced by the various sites and correlated highly with percentage of catchment burned. Principal components analysis quantitatively estimated the degree of temporal change in diatom assemblages at a site. The more extensively burned catchments showed the greatest amount of structural change in diatom taxa among years. Navicula permitis Hust. and Nitzschia inconspicua Grun. were predominant in the heavily disturbed systems, whereas Achnanthes minutissima Kuetz., A. lanceolata (Breb.) Grun., Rhoicosphenia curvata (Kuetz.) Grun. ex Rabh., and Diatoma hiemale var. mesodon (Ehr.) Grun. were common in less disturbed streams. The results demonstrate that recovery trajectories of lotic diatom assemblages following major landscape-scale disturbances are a function of disturbance intensity resulting from differences in catchment characteristics.     

Certain observations on Scytonema stuposum (Kuetz.) Born. (Cyanophyta,Nostocales)

Some interesting cultural observations on Scytonema stuposum (Kuetz.) Born., were recorded. It was observed that frequently one or more terminal cells of a branch get cut off but they still remain attached over the sheath of the mother filament. Even in this condition such structures continue their growth and may become a multicellular body. Later, such a structure gets detached from the mother filament and serve as a hormogonium.     

Reproductive ecology of four subtidal red algae

The reproduction and stature of the red algae Callophyllis cristata (C. Ag.) Kuetz., Membranoptera alata (Huds.) Stackh., Phycodrys rubens (Huds.) Batt., and Ptilota serrata Kuetz. were recorded from subtidal populations at Appledore Island, Maine, U.S.A., with respect to time and depth. Only Membranoptera alata exhibited a conspicuous seasonal fluctuation of reproduction. A vertical gradient of reproduction was evident, with reduced levels of reproduction in shallow populations of Phycodrys rubens and Ptilota serrata, as well as deep populations of Phycodrys rubens, Membranoptera alata and Callophyllis cristata. Differential stratification of the reproductive phases of Ptilota serrata occurred with higher frequencies of tetrasporic plants in deep populations and of cystocarpic plants in shallow populations. In contrast, the haploid and diploid plants of the other three species showed similar distributional patterns. Membranoptera alata, Phycodrys rubens, and Callophyllis cristata showed a conspicuous decrease in stature during maximum reproduction.     

Allelopathic influence of algae on the growth of Eichhornia crassipes (Mart.) Solms

The growth of Eichhornia crassipes (Mart.) Solms was inhibited when grown in water containing algae such as Scenedesmus bijugatis (Turp.) Kuetz, Chlorella pyrenoidosa Chick and species of Aphanothece, Euglena, Merismopedia and Coelastrum. The size of plants, their dry weight and chlorophyll a and b contents and their rate of vegetative propagation were very much reduced compared with control plants grown in algae-free water. The hyacinth plants ultimately died after 90–100 days of growth with algae.     

Notes on the taxonomy of Diplotaxis DC. (Brassiceae)

Taxonomic changes in three species of Diplotaxis are proposed. Diplotaxis erucoides (L.) DC. subsp. cossoniana (Boiss.) Martinez-Laborde, comb, et stat. nov. is proposed for the Algerian subspecies of D. erucoides. Two North African varieties are raised to subspecific rank: D. tenuisiliqua Del. subsp. rupestris (Ball) Martinez-Laborde, stat. nov. and D. muralis (L.) DC. subsp. ceratophylla (Batt.) Martinez-Laborde, stat. nov.     

香蕉33个品种的RAPD研究

利用RAPD技术对香蕉（Musa nana Lour.)33个品种的遗传变异进行了研究,从249个随机引物中筛选出18个有效引物,用它们共扩增出192条DNA带,其中183条为多态性带,占95．31％,平均每个引物扩增的DNA带数为10．67条,利用18个有效引物扩增的192条DNA带对香蕉33个品种间的亲缘关系进行UPGMA聚类分析,计算出33个品种间的平均遗传距离为0．3412。在此基础上建立了香蕉33个品种的DNA分子系统树状图。该系统将香蕉33个品种划归A,B,C和D4个群,其中A群20个品种,B群5个品种,C群2个品种,D群6个品种;A群又可以分为3个亚群。对香蕉遗传多样性分子基础进行了探讨。     

Isolation and chemical characterization of gas-vacuole membranes fromMicrocystis aeruginosa Kuetz. emend. Elenkin

Summary A method involving penicillin treatment was developed to osmotically lyse the cells of the blue-green alga,Microcystis aeruginosa Kuetz. emend. Elenkin, and release the pressure-sensitive gas vacuoles intact. The gas vacuoles were purified by liquid-polymer partitioning or by macromolecular sieving and centrifugation. The degree of purification of the gas vacuoles was followed by observation in the electron microscope and by the use of C¹⁴-labeled vacuolated and nonvacuolated strains ofM. aeruginosa. The gas-vacuole membrane is composed of only protein consisting of 10% basic, 18% acidic and 52% non-polar amino acids.Supported by U.S. Atomic Energy Commission, Contract No. AT(11-1)-1338.     

Strain selection and cell isolation of Ulvaria oxysperma (Kuetz.) Bliding (Chlorophyta) for net cultivation

North Carolina and Bermuda isolates of the green seaweed Ulvaria oxysperma (Kuetz.) Bliding were grown in cross-gradient light-temperature culture to determine the effects of varied photon fluence rates, temperature and photoperiod on their growth and reproduction. Results indicated significant genetic-based variation between the two populations. Spheroplast were obtained from the vegetative thallus of the North Carolina isolate following enzymatic digestion with abalone gut extract and maceration. Single cell isolates developed new cell walls in 2–3 days and attached to nylon net substrate. Cultured isolates regenerated into juvenile plants with normal development and morphology. Results are discussed in terms of the suitability of this economically important species for land-based mariculture.     

距离分析方法与杂种优势

对于75个小麦品种两年的试验结果,采用不同方法进行距离比较分析。结果表明:用表型平均值相关阵经主成分转换,计算品种间欧氏距离,再用类平均法聚类,似乎是适宜的距离分析方法。D~2值在年份间较稳定,不同年份的D~2估值,可用于预测杂种优势。根据13个性状估算的品种间距离(D~2)与株粒重杂种优势(H)之间呈曲线关系,其理论方程是:Y=-3.65 6.665X--0.1288X~2。根据该方程推算:D~2=25.87时,H出现最大值。     

Diospyros foliosa: the correct name for D. elliptica, and new combinations in Fijian and Samoan Diospyros (Ebenaceae)

The correct name in Diospyros L. (Ebenaceae) for a species from Tonga first described as Maba elliptica J. R. Forst. & G. Forst. and incorrectly known as D. elliptica (J. R. Forst. & G. Forst.) P. S. Green is D. foliosa (A. Gray) Bakh. In addition to the nominate variety, six additional varieties are recognised from Fiji and Samoa. As these varieties lack names under D. foliosa, the following new combinations are proposed: D. foliosa var. elliptica (J. R. Forst. & G. Forst.) Dorr, D. foliosa var. fijiensis (Bakh.) Dorr, D. foliosa var. fructuosa (A. C. Sm.) Dorr, D. foliosa var. iridea (Fosberg) Dorr, D. foliosa var. opaca (A. C. Sm.) Dorr, and D. foliosa var. savaiiensis (Christoph.) Dorr.     

Variation in functional ascospore parts in the ascomycetous yeast Dipodascopsis uninucleata

A variation in functional ascospore morphology was detected using electron microscopy (EM) in two varieties of the yeast Dipodascopsis uninucleata, i.e., D. uninucleata var. uninucleata and D. uninucleata var. wickerhamii. It was found that the latter produces ascospores characterized by the absence of small surface hooks which have been implicated in the release and re-assembly of ascospores in D. uninucleata var. uninucleata. These varieties are closely related on the basis of their mode of sexual reproduction, ascospore morphology as observed under the light microscope, physiological characteristics as well as the extent of divergence in the variable D1/D2 domain of the large subunit 26S ribosomal DNA.     

Effect of soybean varieties on survival and fecundity of western corn rootworm

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of corn (Zea mays L.) in North America and has evolved resistance to crop rotation by ovipositing in alternate crops such as soybeans [Glycine max (L.) Merr.]. Through experiments with plants grown in the greenhouse and the field, we tested whether soybeans with resistance to the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), affected survival, fecundity, and consumption of soybean for D. v. virgifera. Soybean varieties tested included those types resistant to A. glycines (Rag1 and rag1/rag3) and a susceptible near isoline of the Rag1 variety. Females were provided with a diet of corn tissue for 4 d after which they were fed a diet of tissue from one of three soybean varieties for 4 d, starved for 4 d, or fed corn tissue. When fed greenhouse grown plants, strains differed significantly in survival and consumption, but consumption did not differ by variety of soybean. Diet treatment only affected fecundity; individuals fed corn continuously had greater fecundity than those individuals fed soybeans. In the experiment with plants grown in the field, leaf consumption differed among strains and individuals fed corn continuously had greater fecundity than the other treatments. Soybean varieties with Rag1 and rag1/rag3 resistance to A. glycines did not appear to affect the fitness of D. v. virgifera. Thus, planting of these A. glycines-resistant soybean varieties should not directly affect the spread of rotation-resistant D. v. virgifera.     

田间不同品种蔬菜对萝卜蚜种群的影响(英文)

本试验通过利用５个品种蔬菜（萝卜,芥蓝,芥菜,菜芯和白菜）研究萝卜蚜（Ｌｉｐａｐｈｉｓ ｅｒｙｓｉｍｉ）在不同蔬菜上的种群动态以及对寄生于萝卜蚜的菜蚜茧蜂（Ｄｉａｅｒｅｔｉｅｌｌａ　ｒａｐａｅ）种群的影响。研究结果显示,在３０天研究期间,有翅萝卜蚜的平均虫口（蚜虫数／苗）在萝卜、芥蓝、芥菜、菜芯和白菜苗上分别为３．９１８、０．８３１、１．１４９、１．７４３和５．２３头,表明降落在萝卜苗上的有翅蚜数量显著地比在其它蔬菜苗上的高;而无翅萝卜蚜的中均虫口分别为６３．４２１、１０．０４１、２４．９２８、２３．３２３和１１４．３０８头,说明萝卜蚜无翅蚜在白菜上的种群显著地高于其它品种蔬菜上的。由于萝卜蚜在不同品种蔬菜上的种群不同,导致菜蚜茧峰种群在不同品种蔬菜上也不同,其僵蚜虫口分别为１．０５６、０．２５１、０．２７７、０．６５１和１．４４头,显示了在萝卜和白菜上的僵蚜数量显著地比其它蔬菜上的高。分析结果表明,萝卜蚜的种群（ｘ）与菜蚜茧峰的种群（ｙ）呈显著的相关关系：ｙ＝０．１１８８＋０．０１４３ｘ（ｒ＝０．９７３９）。本研究还利用试验结果提出了萝卜蚜无翅蚜种群从蔬菜在田间种植后达到防治指标（５０头／苗）的临界天数（ｃ     

Comparison of male adult population densities of the oriental and artocarpus fruit flies,Dacus spp. (Diptera: Tephritidae), in two nearby villages in Penang,Malaysia

The populations of native male adult oriental fruit fly Dacus dorsalis (Hendel ) and artocarpus fruit fly D. umbrosus (F.) in two selected site (BU and SD) were estimated weekly by the capture-recapture technique using live traps baited with methyl eugenol. In BU where many varieties of fruit trees were grown, the estimated population densities of D. dorsalis were between 980 and 3100 male flies per ha between May and July, 1984. During the same period, in SD where there were fewer number and varieties of fruit trees, the estimated population densities were between 300 and 1000 flies per ha. The estimated population densities of D. umbrosus over the same period were between 570 and 1290 flies per ha in BU; and between 5 and 95 flies per ha in SD. Of a total 6828 marked D. dorsalis flies released only one fly (released 6 weeks earlier in BU) was caught in a different site.     

A phenetic analysis and revision of Guineo-Congolean rain forest taxa of Chlorophytum (Anthericaceae)

The taxonomy of rain forest species of the genus Chlorophytum in central and west Africa has to date been difficult to resolve. Plants collected in the Guineo-Congolean plant geographical region deposited in several herbaria formed the basis for a morphometric analysis using Principal Component Analyses and including 16 characters. In total, 166 individuals were included from 461 herbarium collections, from which 57 seeds were scanned to investigate the surface structures. Eight species are recognized, including one with three subspecies and another with three varieties. Four new combinations are proposed ( Chlorophytum comosum (Thunb.) Jacques var. bipindense (Engl. & K. Krause) A.D. Poulsen & Nordal, C. comosum (Thunb.) Jacques var. sparsiflorum (Baker) A.D. Poulsen & Nordal, C. lancifolium Baker ssp. cordatum (Engl.) A.D. Poulsen & Nordal, and C. lancifolium Baker ssp. togoense (Engl.) A.D. Poulsen & Nordal), ten new synonyms are introduced and three lectotypes are designated.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 1–20.     

EFFECTS OF HOST PLANTS ON POPULATION DYNAMICS OF LIPAPHIS ERYSIMI (KALT.) IN THE FIELD

Abstract The population dynamics of alates and apterous of turnip aphid (TA) Lipaphis erysimi (Kalt.) together with the incidence of parasitism by Diaeretiella rapae (M'Intosh) on five host vegetable varieties in the field were evaluated. The results showed that the average populations of TA apterous on host vegetable varieties turnip, Chinese kale, leaf mustard, flowering cabbage and Chinese cabbage were 63. 425, 10. 041, 24. 928, 23. 323 and 114. 308 aphids/plant, respectively. The 'critical day' was used to estimate the date when TA population density on host vegetable varieties reaches its economic threshold. The relationship between TA apterous population ( x ) and mummy aphids parasitized by parasitoid D. rapae was significant, and the regression formula is y = 0. 1211 + 0. 01431 (r=0. 9739**).