Cytogenetic Studies in Cochlearia L. The chromosomal homogeneity within both the 2n = 12 diploids and the 2n = 14 diploids and the cytogenetic relationship between the two chromosome levels

A cytogenetic study has been carried out within the diploidCochleariae. This has demonstrated that all the 2n = 12 taxaare chromosomally homogeneous, as are those with 2n = 14. Itis therefore suggested that the 2n = 12 group be recognisedas C pyrenaica DC, with the morphologically distinct specimensfrom France and Spain at present regarded as C. aestuaria (Lloyd)Heywood being given subspecific rank in C. pyrenaica. It isalso suggested that all the 2n = 14 taxa be regarded as C groenlandicaL. Some doubt is expressed on the existence of C. scotica Druceas a species, as all the specimens of this taxon examined provedto be tetraploid with 2n = 24. Genomic analysis has shown thatthe 2n = 14 group is a primary tetrasomic derivative of the2n = 12 group.     

Morphological Variation in Leucopogon rufus Lindl.: A Preliminary Study

Leucopogon rufus Lindl. is a widespread and morphologicallyvariable species found throughout south-eastern Australia. Ordinationand cluster analyses suggest that the specimens can be separatedinto two or more clusters primarily based on vegetative andfloral features, particularly that of indumentum, a characterthat has previously been regarded as unreliable inLeucopogon.The results indicate that phenetic clustering does occur acrossthe geographic range ofL. rufus. However, since inter-populationvariation is inadequately known these taxa are not formallyrecognized here. Leucopogon rufus Lindl.; morphological variation     

SPECIES DISCRIMINATION AMONG PELAGIC HETEROPODS: RESOLUTION OF THE PTEROTRACHEA HIPPOCAMPUS--P. MINUTA PROBLEM

Four species of Pterotrachea are currently recognized, two ofwhich (P. hippocampus Philippi, 1836, and P. minuta Bonnevie,1920) have very similar morphologies. These two species havebeen distinguished mainly on the basis of eye and visceral nucleusshapes; the former with wide, triangular eyes and a short, broadnucleus, and the latter with narrower, triangular eyes and ataller, more slender nucleus. Quantitative and qualitative morphologicaldata were obtained from specimens of P. hippocampus and P. minuta collectedduring two oceanographic sampling programs in the North AtlanticOcean. Comparisons of eye and visceral nucleus shapes (representedby their length to width and length to retinal width ratios,respectively), plotted against body length showed linear decreases,with no justification for the recognition of two separate species.Examination of eye shape across a wide range of body sizes showedthat the width of the retina increases disproportionately with bodygrowth (by elongation and medial upturning) beginning at a length ofabout 21-22 mm. As a result, the overall appearance of the eyeat this body size changes such that smaller animals (less than21-22 mm) have eyes corresponding with those of P. minuta, whilethe eyes of individuals larger than this body length match thoseof P. hippocampus. Several authors have distinguished femalesof the two species by the presence (P. hippocampus) or absence (P.minuta) of cuticular spines anterior to the eyes. Examinationof female specimens showed that those less than about 30 mmlacked these spines, while those above this size possessed them.Thus, cuticular spines represent a secondary female sexual characteristic. Other morphological features that have been used by previousauthors to distinguish the two species were examined and rejected.Because P. hippocampus was described prior to P. minuta, itis herein regarded as the senior synonym of P. minuta. (Received 12 June 1997; accepted 21 May 1999)     

Ontogeny and distribution of Hygophum benoiti(Pisces, Myctophidae) of the North Western Mediterranean

Two species of the lanternfish genus Hygophum, H.benoiti andH.hygomii, are present in the Mediterranean. Differentiationof the larvae from these two species has been problematic. Anattempt to identify such larvae in the plankton samples of theNorth Western Mediterranean led to a broader study that includedthe examination of a large number of plankton samples collectedin the region since 1976. The large number of Hygophum larvaeobtained during July 1992 in the North Western Mediterranean(that proved to be H.benoiti), together with collections oflarvae from different geographic areas (especially H.hygomiifrom the Southwest Indian Ocean), allowed a detailed morphometriccomparison of the larvae of H.benoiti and H.hygomii. Developmentalstages of H.benoiti from yolk sac to post-flexion larvae aredescribed. Information on the temporal occurrence of H.benoitiin the plankton, as well as the spatial distribution of thisspecies during the survey of peak abundance (June/July 1992)in the North Western Mediterranean, is presented.     

Recent introduction of the planktonic calanoid copepod Sinocalanns doerrii (Centropagidae) from mainland China to the Sacramento-San Joaquin Estuary of California

The planktonic calanoid copepod, Sinocalanus doerrii, a nativeof the rivers of mainland China was found in 1978 in California'sSacramento-San Joaquin Estuary during routine plankton sampling.Previous plankton surveys in 1963 and from 1972 to the presentindicate that the introduction occurred a relativery short timebefore specimens were first caught. The most probable mode ofintroduction is ballast water from Japanese freighters previouslydocking in China. S. doerrii became abundant in the Sacramentoand San Joaquin Rivers in 1979 and may be regarded as well established.Its impact on the native plankton is as yet unknown. ⁴Present address: Department of Biological Science, FloridaState University, Tallahassee, FL 32306, USA. ⁵Present address: 5 Hemingway Street, Branford, CT 06405, USA.     

越南脊额叶蝉属一新种(同翅目：叶蝉科，横脊叶蝉亚科)

脊额叶蝉属Carniata系李子忠、汪廉敏1992年根据贵州标本建立的新属[1],隶于同翅目Homoptera叶蝉科Cicadellidae横脊叶蝉亚科Evacanthinae。目前本属已记载7种[2],主要分布在贵州、云南、四川等省。本文记述了V.Novotny采自越南的一新种。模式标本保存在贵州农学院。端叉脊额叶蝉Carinatahi加rcata新种（图1～6）体连翅长：雄性4．9～5·lin。,雌性5·2～5·5mm。头部比前胸背板窄,头冠前端成角状突出,中域轻度隆起,中央有1明显纵脊,两侧有侧脊,起自头冠顶端,冠面有纵皱纹;单眼位于侧脊外侧,距复限较距头冠顶端近;颜面额唇基…     

BARNACLE-DWELLING EGOTYPES OF THREE BRITISH LITTORINA SPECIES AND THE STATUS OF LITTORINA NEGLECTA BEAN

On the basis of collections from SW Wales and W Ireland it isshown that small (<5 mm) black and/or white Littorina occurringin the barnacle zone on exposed shores, of the L. neglecta shelltype, comprise three species. From their reproductive anatomythese correspond to L. saxatilis, L. arcana and L. nigrolineata,and are interpreted as analogous barnacle-dwelling ecotypesof these species. This adds to the evidence that L. neglectais not a distinct species, but an ecotype of L. saxatilis. (Received 1 June 1992; accepted 23 June 1992)     

Desiccation-Induced Damage and Changes in Total and Heat-Stable Protein Populations in Two Rapeseed Species

Desiccation-induced damage and the capacity to synthesize heat-stableproteins have been examined in two Brassica species. Desiccationdamage to young seedlings, measured as electrolyte leakage andinhibition of overall protein synthesis, is greater in B. napusthan in B.juncea. Constitutive synthesis of heat-stable proteinsis low and declines during desiccation in B. napus while itis relatively high and further increases during desiccationin the case of B.juncea. (Received September 1, 1992; Accepted March 9, 1993)     

Distribution and Production of trans-Aconitic Acid in Barnyard Grass (Echinochloa crus-galli var. oryzicola) as Putative Antifeedant against Brown Planthoppers

A quantitative analysis of organic acid in leaves of barnyardgrass revealed that the contents of trans-aconitic acid werehigh, suggesting that this compound may act as an antifeedantagainst brown planthoppers. However, trans-aconitic acid couldnot be detected in the phloem sap which was considered to bethe main nutrient source for brown planthoppers. trans-Aconiticacid was formed in vitro from cis-aconitic acid through theaconitate isomerase activity which was detected only in theleaf sheath, but not in the leaf blade. (Received August 10, 1992; Accepted November 30, 1992)     

不同保藏处理的昆虫标本DNA提取及其随机扩增多态DNA反应

实验利用CTAB法对柳二十斑叶甲Chrysomela vigintipunctata (Scopoli)、异色瓢虫Harmonia axyridis Pollas、七星瓢虫Coccinella septempunctata Linnaeus、小地老虎Agrotis ypsilon (Rottemberg)、红蜻Crocothemis servilia Drury、无齿稻蝗Oxya abentata Willemse和中华稻蝗Oxya chinensis (Thunberg)等7种昆虫进行了基因组DNA提取。从自然干燥标本、烘干标本及酒精浸泡标本获得的DNA均可用于RAPD-PCR反应,且烘干标本、酒精浸泡标本提取效果优于自然干燥标本。这种提取方法简便易行,容易掌握,且耗资小于其它分子生物学方法。     

An Endogenous Suppressor of the Defense Response in Pisum sativum

Healthy pea plants contain a substance, tentatively called "endogenoussuppressor", which specifically suppresses the accumulationof pisatin in pea plants that is induced by treatment with CuCl₂or an elicitor from Mycosphaerella pinodes. This suppressorelicits the accumulation of phytoalexins in other legumes, suchas kidney bean, soybean and cowpea. The endogenous suppressorfunctions to delay the accumulation of pisatin, the activationof phenylalanine ammonialyase (PAL) and the accumulation ofmRNAs for PAL and chalcone synthase induced by the elicitorfrom M. pinodes. The substance specifically induces susceptibilityto nonpathogens, such as Mycosphaerella ligulicola and M. melonis,in pea out of four species of legume tested, but the effectis not cultivar-specific. Thus, the endogenous suppressor inhealthy pea plants suppresses a series of self-defense reactionsand induces susceptibility in pea plants in a species-specificmanner, being similar to the exogenous fungal suppressor fromthe pea pathogen, M.pinodes. (Received February 19, 1992; Accepted May 11, 1992)     

SPERM AND SPERMIOGENESIS IN OPISTHOTEUTHIS PERSEPHONE (OCTOPODA: CIRRATA): ULTRASTRUCTURE, COMPARISON WITH OTHER CEPHALOPODS AND EVOLUTIONARY SIGNIFICANCE

Ultrastructural features of spermiogenesis and mature spermatozoaare described for the first time in a cirrate octopod. Comparisonwith other investigated cephalopod species shows that spermatozoaof Opisthoteuthis persephone Berry most closely resemble thoseof the genus Octopus. The shared features include: (1) an elongate,solid acrosome with internal banding and a prominent helicalkeel; (2) a straight, rod-like nucleus; (3) a short midpieceand (4) a post-mitochondrial (‘annular’) skirt.Of these, the acrosomal morphology is most significant taxo-nomically,as the internal banding of the acrosomal vesicle only occursin the Octopoda. Spermatozoa of Opisthoteuthis and Octopus differhowever in the extent of the internal banding of the acrosome(poorly developed in Opisthoteuthis) and substructure of theacrosomal keel (more complex in Opisthoteuthis). Surprisingly,the extensive fibrous plug of Octopus and Vampyroteuthis sperm,is not developed either in Opisthoteuthis or in Eledone. Resultsprovide additional support for the monophyly of the Octopodabut also hint at the possibility that some groups of in-cirratesmay not be as advanced as generally believed. (Received 6 July 1992; accepted 18 August 1992)     

Development of the diatom-Phaeocystis spring bloom in the Dutch coastal zone of the North Sea: the silicon depletion versus the daily irradiance threshold hypothesis

The Dutch coastal zone of the North Sea is characterized byhigh nutrient inputs and low water column irradiance due tohigh concentrations of suspended matter. The vernal phytoplanktonblooms are dominated by diatoms and the flagellate Phaeocystis(Haptophyta). Two hypotheses that predict the timing of thePhaeocystzs bloom were tested with field data collected in 1992.The first one, stating that the Phaeocystis bloom starts whensilicon has been depleted by a preceding diatom bloom, couldnot be bracketed with observations. The second hypothesis, predictingthat Phaeocysus blooms under nitrogen- and phosphorus-repleteconditions after a daily irradiance threshold has been passedcould be supported by field observations. Furthermore, it isshown that the Dutch coastal zone is not continuously homogeneouslymixed. It is argued that this is an important factor in thelife cycle of Phaeocystis and in foam formation on nearby shores.Grazing by the ciliate Strombidium sulcatum and heterotrophicgymnodinoid flagellates accounted for 92% of Phaeocystis cellloss after the bloom.     

VR-ACS6 is an Auxin-Inducible l-Aminocyclopropane-l-carboxylate Synthase Gene in Mungbean (Vigna radiata)

We have isolated four cDNA clones of ACC synthase from etiolatedmungbean seedlings treated with auxin. PVR-ACS2, pVR-ACS3 andpVR-ACS6 contained the same sequences as the previously reportedDNA fragments, pMAC2, pMAC3 (Botella et al. 1992b) and pMBAl(Kim et al. 1992), respectively. pVR-ACSl was identical withpAIM-1 (Botella et al. 1992a). VR-ACS6 was specifically induced in response to the auxin signal.The IAA-induction of VR-ACS6 was very rapid (within 30 min)and insensitive to cycloheximide treatment at concentrationsup to 100 µM. Significant accumulation of VR-ACS6 mRNAwas detected at 1 µM.IAA.The IAA-induced expression ofVR-ACS6 was suppressed by ABA and ethylene, but enhanced byBA. These characteristics of VR-ACS6 expression were well correlatedwith the physiological data of auxin-induced ethylene productionin mungbean hypocotyls. VR-ACS1 was strongly induced by cycloheximide, but was foundto be not auxin-specific. Inhibitors of either ethylene biosynthesis(AOA) or action (NBD) increased the basal level of VR-ACS1 mRNA. (Received May 7, 1996; Accepted November 25, 1996)     

Presence of a Pathway for the Biosynthesis of Auxin via Indole-3-Acetamide in Trifoliata Orange

The auxin-biosynthetic pathway from L-tryptophan to indole-3-aceticadd via indole-3-acetamide (IAM), found in plant-pathogenicbacteria such as Agrobacterium tumefaciens and Pseudomonas savastanoi,has not been found in plants. We attempted to detect the enzymaticactivities for this pathway in cell-free systems from varioustissues of trifoliata orange (Poncirus trifoliata Rafin.). Ahigh level of activity of LAM hydrolase, which catalyzes theconversion of IAM to indole-3-acetic acid, was observed in acrude extract prepared from young fruits one week after fullbloom. Using -naphthaleneacetamide as a competitor of IAM hydrolase,a simple assay system was developed for the detection of theconversion of L-tryptophan to IAM (tryptophan monooxygenaseactivity). When this system was used to assay cell-free extractsof young fruit of P. trifoliata, the conversion of L-tryptophanto IAM was clearly demonstrated by the presence of IAM amongreaction products, as demonstrated by GC/MS analysis and theincorporation of ¹⁴C-labeled L-tryptophan into an IAM fraction.This is the first report indicating the presence of an auxin-biosyntheticpathway via IAM in P. trifoliata. Furthermore, it is shown thatboth enzyme activities in auxin biosynthesis increased transientlyduring fruit development. (Received October 9, 1992; Accepted November 2, 1992)     

Isolation of the Photoactive Reaction Center Complex that Contains Three Types of Fe-S Centers and a Cytochrome c Subunit from the Green Sulfur Bacterium Chlorobium limicola f. thiosulfatophilum, Strain Larsen

The photoactive reaction center (RC) complex from the greensulfur bacterium Chlorobium limicola f. thiosulfatophilum, strainLarsen, was isolated after solubilization and ammonium sulfatefractionation followed by ion-exchange chromatography. The spectrumof the complex was almost identical with that of the similarRC complex isolated by Feiler et al. [(1992) Biochemistry 31:2608–2614] except for the presence of cytochrome c₅₅₁instead of c₅₅₃ in the latter study. A molecular ratio of BChla to P840 of the isolated RC complex was assayed to be 25–35.SDSPAGE analysis revealed that the isolated complex containedthree major polypeptides with apparent molecular masses of 68,41 and 21 kDa, respectively. The 21-kDa polypeptide was identifiedto be a heme-binding protein by staining the gel for peroxidaseactivity. The cytochrome c₅₅₁ was oxidized by flash light ina biphasic manner with half times of 90 and 390 µs, respectively,that coincided with the reduction half times of P840⁺. Threedistinct iron-sulfur centers assigned to F_A, F_B and F_x, respectively,from their g-values were detected by EPR spectroscopy at cryogenictemperature. These results suggest that the present preparationcontains a minimal functional unit of the RC of this bacterium,and that this complex appears to lie on a evolutionary linebetween RC's of purple bacteria and photosystem I. (Received August 18, 1992; Accepted October 28, 1992)