摘要:

SUMMARYObservations are presented on the morphology and life histories ofChromastrum kylinoides(Feldm.) comb. nov.,Kylinia rosulataRosenv., andAudouinella pectinata(Kylin) Papenfuss. Each species shows an alternation of dissimilar generations.Although in earlier publicationsC. kylinoidesandK. rosulatahave been confused, andA. pectinatahas been considered conspecific withK. rosulata, it is concluded in the present study that the species are quite different and should be assigned to separate genera.The tetrasporophyte ofC. kylinoidesisChromastrum reductum(Rosenv.) comb. nov.. The tetrasporophyte ofK. rosulatawas indentified asAcrochaetium strictum(Rosenv.) Hamel. The gametophyte ofA. pectinataappears not to have been described as a separate entity from the European coast.A critical evaluation of life histories in the Acrochaetiaceae is supposed to alter the current classifications of the species in this family of red algae.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00328.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYThe wood anatomy of 18 genera belonging to the Lythraceae is described. The diversity in wood structure of extant Lythraceae is hypothesized to be derived from a prototype with scanty paratracheal parenchyma, heterogeneous I uniseriate and multiseriate rays, (septate) libriform fibres with minutely bordered pits, and vessels with simple perforations. These characters still prevail in a number of Lythraceae. Specialization has been very limited in most Lythraceae of shrubby or herbaceous habit: these have juvenilistic rays composed mainly of erect rays and sometimes completely lack axial parenchyma. Ray specialization towards predominantly uniseriate homogeneous rays, concomitant with fibre dimorphism leading to abundant parenchyma differentiation, and with the advent of chambered crystalliferous fibres has been traced in the “series”Ginoria, Pehria, Lawsonia, PhysocalymmaandLagerstroemia. The latter genus has the most specialized wood anatomy in the family and has species with abundant parenchyma as well as species with alternating bands of dimorphous septate fibres.Pemphisrepresents an independent specialization with its vasicentric parenchyma and thick‐walled nonseptate fibres.The affinities of Lythraceae with other Myrtales are discussed.Punica, Rhynchocalyx, Psiloxylon, Oliniaceae,Alzatea, Sonneratiaceae, Onagraceae and Melastomataceae all resemble Lythraceae in their wood anatomy. The former three genera could even be accommodated in the family without extending its wood anatomical range. Oliniaceae,AlzateaandSonneratiaonly differ in minor details from Lythraceae. In order to facilitate identification of wood samples, tentative keys to the genera or groups of genera of Lythraceae as well as to some species ofLagerstroemiaare pres

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00329.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYThe mature xylem ofAlzateais described for the first time, based on material from its new locality in Costa Rica. The wood anatomy pleads against inclusion ofAlzateain Crypteroniaceae but can be cited in favour of Lythraceous affinities of the genus.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00330.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYThe postgenital fusion of the carpel margins of the gynoecium ofLaburnocytisus adamii(Poit.) Schneid is described in detail using light and electron microscopy. In this species, the cells of dermal origin are characterized by osmiophilic bodies, facilitating the localisation of the enclosed dermal tissue at the site of fusion. The osmiophilic bodies are abundant in the outer epidermis and decrease in number and size towards the inner part of the enclosed dermal tissue. They are absent from the inner epidermis. Reasons for this distribution pattern are discussed. Variation in cell configuration and width of the enclosed dermal layer are probably caused by differences in growth rate between dermal and subdermal tissue.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00331.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYSpecific identification of flat forms of theLemna gibba/L. minorcomplex on morphological grounds appears to be possible only when the dimensions are>5.0 × 3.5 mm or/and the number of veins is>5(L. gibba), or when the dimensions are<3.0 × 2.0 mm, the number of veins 3 and/or the width/length ratio<0.60(L. minor). A consistent diagnostic character is the ability ofL. gibbaof turning gibbous when cultivated on EDDHA containing mediu

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00332.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYThe pollination ecology of five species of Rhinanthoideae (the annual speciesRhinanthus serotinus, R. minorandMelampyrum pratense, the biennialPedicularis sylvaticaand the annual and biennialP. palustris)has been investigated.All species contain pollen and nectar and are frequently visited by sternotribically and nototribically pollinating bumblebees. The effectiveness of pollen transfer has been measured by the use of fluorescent powder. InR. serotinusandM. pratenseno differences exist in percentages of fluorescent stigmas of flowers nototribically or sternotribically visited by bumblebees.R. minorflowers, visited sternotribically, have very low percentages of fluorescent stigmas. This indicates that the pollen‐covered venter cannot touch stigmas enclosed by the galea; the movements of the bumblebees probably caused self‐pollination.P. palustris, R. serotinusandM. pratenseflowers are very frequently perforated by nectar‐collecting short‐tongued bumblebees.P. sylvaticaandR. minorflowers are very rarely perforated. On these species nectar is mainly collected by nototribically pollinating bumblebees. Seed production and dependence upon pollination by bumblebees (BombusLatr. spp.) are considered.A range from high dependence upon bumblebee visits for seed production inP. palustris, to medium dependence inP. sylvaticaandR. serotinusand virtual independence inR. minorandM. pratenseis established. No species is completely self‐sterile. Seed set in caged plants is due to favourable morphology and position of flowers. Close proximity of thecae and stigma or a downward curving of the pistil under pollen chamber inMelampyrumandRhinanthusinsure seed set in caged plants. InPedicularisthese characteristics for self‐pollination are absent.The importance of bumblebees for the fiveRhinanthoideaeand the reciprocal importance of these pollen and nectar providing plants for bumblebees is discussed. The importance of alternative pollination by honeybees, thrips and wind i

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00333.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYA comparison was made of the activities of peroxidase, chlorogenic acid oxidase, glucose‐6‐phosphate dehydrogenase and of peroxidase isoenzymes in the transmitting tissue and the cortex of unpollinatedNicotiana alatastyles.Whereas most peroxidase and chlorogenic acid oxidase activity in a style occurred in the cortex, the activity of glucose‐6‐phosphate dehydrogenase, on the contrary, was highest in the extracts of transmitting tissue.Comparison of peroxidase and glucose‐6‐ phosphate dehydrogenase activities in the style extracts with the sum of the activities present in the cortex and transmitting tissue, when measured separately revealed discrepancies which can be explained by the presence of enzyme inhibitors.Starch gel electrophoresis showed that two peroxidase isoenzymes occur in the transmitting tissue, namely No. 12, a major one which was specific for this tissue and a minor one, No. 7 that was also found in the cortex. The peroxidase isoenzyme No. 10, which has previously been suggested to be involved in the regulation of pollen tube growth occurs only in the cortex, thus indicating that it influences the pollen tube growth indirectly.The possible interactions between chlorogenic acid and the enzymes, peroxidase and chlorogenic acid oxidase in relation to pollen tube growth ar

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00334.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYThe protonemata ofFunaria hygrometricaHedw. were shown to photorespire, first by demonstrating that immediately after a period of illumination oxygen was consumed at a rate greater than that characteristic of long‐term dark respiration, and secondly by observing a greater release of14CO2from 1 –14C glycolate in light than in darkness. The glycolate‐oxidizing enzyme had the ability to decompose L(–) lactate but not D(–) lactate, and must therefore be considered to be a glycolate oxidase and not a glycolate dehydrogenase such as operative in some algae. Some implications of these findings are

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00335.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYIn leaves of dark grown bean, the degree of reversibility by far red of red‐induced induction of rapid chlorophyll accumulation in white light depends upon the duration of a dark period between short red and far red irradiations. Reversibility reaches a maximum for a dark period of about 9 s. It is proposed that this can be explained by interaction of at least two first order processes. The first, with a rate constant at 20 °C of 0.23 s−1, is thought to represent migration of Pfrto sensitive sites. The second, with a rate constant of 0.1 s−1is the escape from phytochrome control of one of the early steps in the induction p

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00336.x

年代:1979

数据来源: WILEY

摘要:

SUMMARYSieve tube exudate was obtained fromRicinus communisplants grown on nutrient solutions with varying K: Ca ratio. The K: Ca ratio of the leaves and that of the exudate both appeared to be correlated with the ratio of the nutrient solution. The observed correlations explain the generally observed linkage between the Ca‐level in transpiring green plant parts and the degree of severity of Ca‐deficiency disorders sometimes observed in fruits, seeds or other carbohydrate sink regi

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1979.tb00337.x

年代:1979

数据来源: WILEY