Book Reviews

Book reviewed in this article:
Kröber, H ., Erfahrungen mit Phytophthora de Bary und Pythium Pringsheim. [Experiences with Phytophthora de Bary and Pythium Pringsheim].
J. A. Roberts and G. A. Tucker (Eds.) , Ethylene and Plant development.     

REAPPRAISAL OF UTRICULARIA INFLATA AND U. RADIATA (LENTIBULARIACEAE)

Reinert , Grady , W., and R. K. Godfrey . (Florida State U., Tallahassee.) Reappraisal of Utricularia inflata and U. radiata (Lentibulariaceae). Amer. Jour. Bot. 49(3): 213–220. Illus. 1962.—Utricularia inflata and U. radiata, interpreted either as separate species or 2 varieties of a single species by previous investigators, are shown to be specifically distinct on the basis of 5 hitherto-neglected, morphological characters, 4 of which are vegetative in nature, and on the basis of 3 reinvestigated quantitative criteria. The particular attention devoted to the vegetative bodies of the 2 plants led to the discovery, in U. inflata, of tuber formation, a phenomenon known to occur in Utricularias in general but unreported for North American species. Support for interpreting U. inflata and U. radiata as species resides in the distribution patterns. Although both occur on the outer coastal plain from southern Alabama to southern Delaware, the 2 taxa are easily distinguishable and exhibit no intergradation. The range of U. radiata is much broader; it extends westward to eastern Texas northeastward to Nova Scotia, and is disjunct inland in western Tennessee, western Virginia and in northwestern Indiana.     

A new species of <Emphasis Type="Italic">Utricularia</Emphasis> (Lentibulariaceae) from Guerrero,Mexico

Utricularia regia is described and illustrated. It occurs in the Sierra Madre del Sur region of Guerrero, Mexico, and belongs to section Psyllosperma; a key to differentiate the species of sect. Psyllosperma is included. The new species is similar to Utricularia hintonii and U. petersoniae, from which it differs in the unusual division of the upper lip of the corolla into four lobes and its peculiar coloration pattern. A table comparing the differences among these three species is presented. Utricularia regia adds a new, narrowly endemic species to the flora of Guerrero, Mexico.

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Resumen  Se describe e ilustra como especie nueva para la ciencia a Utricularia regia a partir de ejemplares procedentes del estado de Guerrero, México. La nueva especie se ubica en la sección Psyllosperma y está mejor relacionada con Utricularia hintonii y U. petersoniae; de las que se diferencia por la división del labio superior de la corola en cuatro lóbulos y por su peculiar coloración; se presenta una tabla en la que se comparan más ampliamente estas tres especies y se incluye también una clave para diferenciar las especies de la sección Psyllosperma. Utricularia regia agrega un elemento endémico más a la flora de Guerrero y de México.

     

A COMPARISON OF VARIABILITY IN UTRICULARIA CORNUTA AND UTRICULARIA JUNCEA

Although Utricularia cornuta Michx. and U. juncea Vahl, sympatric in the southeastern United States, have been considered conspecific by various authors, the present biosystematic approach shows them to be separate species. The taxa are seasonally isolated. While both have the same chromosome number (n = 9), strong internal isolation is apparent since artificial hybrids cannot be produced by standard methods. In Utricularia cornuta the mean values of characters studied quantitatively are much higher than those of U. juncea though the extremes of the ranges may overlap. Utricularia juncea has both cleistogamous flowers and chasmogamous flowers while U. cornuta has only chasmogamous flowers. The flowers are self-fertile and apparently are usually, if not always, self-pollinated, even though they are highly adapted to specialized insect pollinators.     

The effect of bladderwort (Utricularia) predation on microcrustacean prey

SUMMARY 1. The effects of the carnivorous plant Utricularia ( bladderwort) on its microcrustacean and macroinvertebrate prey were studied under seminatural and natural conditions. The results suggest that Utricularia is a strong interactor in littoral communities that influences its prey populations by direct predation and indirect facilitation.
2. In an 8-week enclosure experiment, effects on prey density were compared in three treatments with (1) U. vulgaris with intact trapbladders, (2) U. vulgaris without bladders and (3) no Utricularia present.
3. Utricularia predation caused a decrease in prey density over time, whereas presence of Utricularia without bladders increased prey density. In the controls without Utricularia , prey density was relatively constant over time.
4. Field samples were collected to quantify predation rates of three Utricularia species on two natural prey populations. Daily consumption rates on prey peaked from mid-July to mid-August for all Utricularia species, but were low in June and September. This pattern was explained mainly by a high number of trapbladders at this time, but also by a slight increase in the number of prey caught per bladder. Per capita prey mortality rates caused by Utricularia were substantial and ranged between 0.14 and 0.43 day⁻¹ for copepods, 0.1–0.27 day⁻¹ for ostracods and 0.04–0.2 day⁻¹ for chydorid cladocerans.
5. Predation and facilitation effects were observed for total prey and separately for epiphytic and benthic prey. Planktonic microcrustaceans showed no response to Utricularia presence.     

Variation of sterility and fertility in Utricularia australis f. australis in Hokkaido, northern Japan

Seed-production ability was studied in Utricularia australis R. Br. f. australis Komiya and Shibata through field observation, pollination experiment, pollen culture, and isozyme analysis for populations in various regions of Hokkaido, northern Japan. Utricularia australis f. australis has previously been postulated to be sterile in Japan, however, in the present study, fertile populations were found in eastern Hokkaido. Bisexual sterility and male sterility were suspected to be present in populations in the western part of Hokkaido. There was also a strain that seemed to produce no seed because of intra-clonal inbreeding depression or self-incompatibility. Isozyme analysis of three enzyme systems indicated a uniformity of multienzymatic phenotype (MEP) in each population or region. The MEP grouping of populations corresponded to the type of sterility and fertility revealed by pollination and pollen culture experiments. These experiments suggested that each regional strain had its own sterility or fertility type.     

Nucleotide sequence of the cyanelle genome fromCyanophora paradoxa

The complete nucleotide sequence of the cyanelle genome ofCyanophora paradoxa Pringsheim strain LB 555 was determined (accession number U30821). The circular molecule is 135,599 base pairs in length. The physical map of this DNA molecule is shown along with identified genes and open reading frames.     

Presence of two types of flowers with respect to nectar sugar in two gregariously flowering species

Many species of animal-pollinated flowers are known to vary widely in the nectar content of flowers. Some proportion of flowers in many species is apparently nectarless, and such flowers are believed to be ‘cheaters’. Cheating may explain a part of the variability in nectar content. If cheating exists as a qualitatively different strategy then we expect bimodality in the distribution of nectar content of flowers. It has been shown in a multispecies study that gregarious species have a higher proportion of cheater flowers. We studied the frequency distribution of total nectar sugar in two gregariously flowering species Lantana camara and Utricularia purpurascens, which differed in other floral and ecological characters. At the population level, both the species showed significant bimodality in the total sugar content of flowers. The obvious sources of heterogeneity in the data did not explain bimodality. In Lantana camara, bimodality was observed within flowers of some of the individual plants sampled. In Utricularia purpurascens the proportion of nectarless flowers was more in high-density patches, suggesting that the gregariousness hypothesis may work within a species as well. The results support the hypothesis of cheating as a distinct strategy since two distinct types of flowers were observed in both the species. The effect of density in Utricularia purpurascens also supports the gregariousness hypothesis.     

Functional characteristics of traps of aquatic carnivorous Utricularia species

Firing and resetting of traps in aquatic Utricularia species are associated with water flow and trap volume changes. In this study, trap thickness was used as a measure of water flow and was monitored automatically using an electronic position sensor. The basic characteristics of mechanically stimulated firing and resetting were measured in isolated traps from 13 aquatic Utricularia species and in two trap size categories in Utricularia reflexa. This allowed to study the relationship between these trap functions and trap thickness and length (criteria of trap size). Additionally, the characteristics of spontaneous firings (without any mechanical stimulation) were compared for U. reflexa traps fed or denied prey during a 1-day period. On the absolute scale, the 13 Utricularia species differed considerably in their firing and resetting rates. Significant interspecific differences were also found in the magnitude of firing (in total 3.7–4.2 times) and resetting rates (10–24 times) per unit trap thickness or length. Overall, traps of Utricularia australis, Utricularia stellaris and Utricularia inflata showed the greatest firing and resetting rates. The relative magnitude of firing per unit trap thickness or length showed a highly significant negative correlation with both trap thickness and length and the same also held for the relative resetting rates. Smaller and narrower traps are thus relatively more effective at trap firing and resetting than larger traps. Neither firing nor resetting characteristics were significantly different between unfed and prey-fed traps of U. reflexa and this was also true for the occurrence of spontaneous firings. A strict linear resetting rate, without any lag-period, was found during the first 3 min after trap firing in U. reflexa. This suggests that water is pumped out of the trap continuously and probably recirculates. Given the concepts of spontaneous firing and water recirculation, an ecological model based on the literature data has been devised to quantify the daily N and P gain from the ambient water by Utricularia traps devoid of animal prey. The model shows that the total N and P content estimated in the trap fluid is too high to be accumulated from only the ambient water. This implies that the prey-free traps do not take up N or P from the trap fluid but rather exude a quantity of these nutrients to the fluid to support the microbial community. Therefore, the trap microorganisms behave more as parasites than commensals and represent an additional ecological cost for trap maintenance.     

CRYPTOGLENA PIGRA: A EUGLENOID WITH ONE CHLOROPLAST12

The taxonomic status of Cryptoglena pigra Ehrb., interpreted from observations based on bright-field microscopy, has been uncertain. Examination with the electron microscope of a clone of C pigra isolated by E. G. Pringsheim reveals certain features which, collectively, are distinctly euglenoid: periplast associated with muciferous bodies and subpellicular microtubules; canal and reservoir with microtubules; one flagellum with a swelling and emergent through a canal, and a second flagellum without a swelling and nonremergent; stigma (eyetpot) closely apprrssed to but not part of the chloroplast; nucleus with permanently condensed chromosomes attached to the inner nuclrar membrane; mitochondria with disc-shaped cristae constricted at the base; chloroplast with thylakoids often in triplets; and paramylon grains in the cytoplasm. Unlike most euglenoids, C. pigra possesses a single chloroplast that in transverse thin sections is U-shaped.     

<Emphasis Type="Italic">Utricularia rostrata</Emphasis> (Lentibulariaceae), a new species from the Chapada Diamantina,Brazil

Summary   Utricularia rostrata A. Fleischm. & Rivadavia (Lentibulariaceae) is described from the Chapada Diamantina highlands in Bahia state, north-eastern Brazil. The morphological characteristics which distinguish this new species are discussed, together with its distribution and ecology.     

Predation by the tropical plant Utricularia foliosa

1. We examined the prey captured by individual plants of the tropical carnivorous plant Utricularia foliosa, located in different areas along a creek in the Colombian Amazon and the zooplankton and macroinvertebrate communities associated with the plants. The aims were: (i) to determine whether bladders of different sizes within each plant catch different numbers of prey or exploit different size ranges and types of prey, (ii) if the quantity and composition of prey captured varies temporally and/or spatially and (iii) if the plant has evolved effective mechanisms of attracting prey. 2. Utricularia foliosa captured the most abundant species of macroinvertebrates associated with the plant. Larger bladders captured more, larger and more diverse prey. However, benefits of the extra prey caught by large bladders were not offset by the greater cost of producing bladders larger than approximately 1650 μm. 3. The number of prey captured was higher in those plants with more carbohydrates per bladder and with a higher ratio of antenna size/bladder length. The antennae enhance capture success by offering the prey a favourable substratum that exploits their natural locomotor and feeding behaviour. However, although carbohydrates may lure prey, carbohydrate production was not a strategy of the plant to enhance the capture of prey, because the amount of carbohydrates in the bladder was related to the abundance of periphyton.     

Effects of light and microcrustacean prey on growth and investment in carnivory in Utricularia vulgaris

SUMMARY 1. In a 5-week enclosure experiment, we studied the effects of light (ambient light, low light) and prey availability (no prey, prey added) on growth and investment in carnivory in Utricularia vulgaris .
2. Investment in carnivory, measured as the proportion of biomass allocated to bladders, was strongly affected by our manipulations of light intensity and prey density. In the treatment with high prey density the light reduction decreased the investment in bladders from 25% to zero. The effect of prey density on investment in bladders was negative. Because prey addition increased the concentration of nutrients, especially phosphorus, we propose that the effect of the prey treatment on investment reflected altered nutrient concentrations.
3. Availability of prey increased growth and apical biomass of Utricularia . As Utricularia had very few bladders in some treatments we suggest that the effect was due to a combination of live prey trapped and increased nutrient availability from dead prey.
4. Abundance of periphyton on Utricularia and on the enclosure walls was highest in the treatments with high prey density where nutrient concentrations were highest. Thus we interpret the response of periphyton as primarily reflecting nutrient availability.     

Pythium root rot of crucifers

A destructive root disease of cabbage (Brassica oleracea L. var. capitata) and cauliflower (Brassica oleracea L. var. botrytis) incited by a species of Pythium Pringsheim is described as occurring in Varanasi, U.P. The pathogen was isolated on potato dextrose and corn meal agar. Pathogenicity and host range of the disease were studied. Cultural characters, morphology and developmental stages and life cycle of the fungus indicated its identity with Pythium middletonii Sparrow.     

Open dichotomous venation in the leaves ofUtricularia striatula (Lentibulariaceae)

The open dichotomous pattern of venation in the leaves ofUtricularia striatula is described in detail and compared withCircaeaster andKingdonia. Similar traits of dichotomous venation occur in other species ofUtricularia and may be due to reduction.Studies on IndianUtricularia, 3.     

中国香港17种植物新记录

报道了香港17种植物新记录:无配膜叶铁角蕨[Hymenasplenium apogamum(N.Murak.&Hatan.)Nakaike]、似薄唇蕨(Leptochilus decurrens Blume)、穿心藤[Amydrium hainanense(H.Li,Y.Shiao&S.L.Tseng)H.Li]、毛背...     

Blütenbildung durch tierische Zusatznahrung und andere Faktoren beiUtricularia exoleta R. Braun

Zusammenfassung Zur Angleichung an die Verhältnisse am natürlichen Standort wurden absolute Reinkulturen vonUtricularia exoleta in mineralischer Nährlösung mit toten Daphnien gefüttert, die vorher im Autoklav sterilisiert worden waren.Während die Pflanzen in der Mineralsalzlösung ohne Zusatz rein vegetativ blieben, bildeten sie in den gefütterten Kulturen Blüten.Man darf daher annehmen, daß der Sinn der Insectivorie fürUtricularia exoleta auch am natürlichen Standort der ist, der Pflanze durch Stoffe aus den Beutetieren das Blühen zu ermöglichen. Es handelt sich also nicht um entbehrliche Zusatznahrung, sondern der Tierfang ist unentbehrlich für das Zustandekommen des vollständigen Entwicklungsablaufs der Pflanze.Der gleiche Effekt wurde auch durchDekokt aus Daphnien erzielt und—in Bestätigung von E. u.O. Pringsheim — durch Pepton-Fleischextrakt.Die beste Tageslänge für das Blühen vonUtricularia exoleta sind 11 Std. Zusatz von Gibberellin (1/10000 und 1/100000 Mol) wirkte nicht blühauslösend.Mit 5 Textabbildungen.Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Effects of zooplankton and conductivity on tropical Utricularia foliosa investment in carnivory

Investment by bladderwort (Utricularia foliosa) in carnivory was estimated in lakes from the Colombian and Brazilian Amazon with different dissolved mineral nutrients and prey availability. As zooplankton abundance in the lake decreased, an increase in the number of bladders per leaf and in the mean bladder size was observed. However, this investment increment in carnivory diminished as the overall availability of dissolved ions in the lake increased. Our results show that carnivorous plants U. foliosa optimise their investment in carnivory, changing bladder number and bladder size according to zooplankton abundance and conductivity.