The effect of glucosinolates on responses of young Phyllotreta nemorum larvae to non-host plants

All recorded host plants of Phyllotreta nemorum L. (Coleoptera: Chrysomelidae) contain glucosinolates and belong to the plant families Brassicaceae (Cruciferae), Resedaceae and Capparaceae. The acceptability of 56 plant species from 28 other plant families (non-hosts) for young larvae has been studied in the laboratory. None of these species were fully acceptable for initiations of leaf mines when intact untreated leaves were presented, and only one species, Malva silvestris L. (Malvaceae), was partially acceptable. The acceptability of some species increased when leaf discs were presented instead of intact leaves; but the highest percentages of mine initiations occurred in leaf discs treated with the glucosinolate, sinigrin. A stimulatory effect of sinigrin could be demonstrated in experiments with 7 plant species: Papaver dubium L., Papaver rhoeas L., Fumaria officinalis L., Malva silvestris L., Pisum sativum L., Campanula latifolia L. and Lactuca sativa L. The majority of species remained unacceptable even after treatment with glucosinolates.The main causes for these differences between plant species are supposed to be differences in contents of deterrents and/or other stimulants for mine initiation. These possibilities are discussed in relation to the content of allelochemicals in acceptable plants and the position of these plants in botanical classifications.

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Zusammenfassung Phyllotreta nemorum L. ist ein oligophager Erdfloh, der an Cruciferen und anderen Glukosinolat-haltigen Pflanzenarten gebunden ist. Die Imagines fressen Löcher in die Blätter und die Weibchen legen ihre Eier in den Boden. Die Larven sind Blattminierer. Nach dem Schlüpfen im Boden klettern sie an die Pflanzen hoch, und die Einbohrung und der Anfang der Minierung erfolgt in eines der unteren Blätter der Wirtspflanze.Die Wirkung von Glukosinolaten auf die Einbohrung von Junglarven in Pflanzenarten, die keine natürliche Inhalt von Glukosinolaten haben, ist in Laborexperimenten untersucht worden. 56 Pflanzenarten aus 28 Familien wurden präsentiert teils als unbehandelte Blätter und teils als Glukosinolatbehandelte Blattscheiben. Unbehandelte Blätter von nicht-Glukosinolathaltigen Arten waren immer unbefriedigend für die Larven. Nur in eine Art, Malva silvestris L. war die Frequenz der Einbohrung ein bisschen höher als 10%. Eine signifikante Erhöherung der Anzahl eingebohrten Larven nach der Sinigrin-behandlung erfolgte in 7 Pflanzenarten: Papaver dubium L., P. rhoeas L., Fumaria officinalis L., Malva silvestris L., Pisum sativum L., Campanula latifolia L. und Lactuca sativa L. Doch blieben die meisten Pflanzenarten (84%) auch nach der Sinigrin-Behandlung unbesiedelt.Pflanzenarten, die nach der Sinigrin-Behandlung nicht besiedelt werden enthalten vielleicht frasshemmende Stoffe, oder ihnen fehlen noch weitere Frass-stimulierende Stoffe. Diese Möglichkeiten werden diskutiert in Zusammenhang mit den Inhalt von Allelochemikalien in besiedelten Pflanzenarten und mit ihrer taxonomischer Position.

     

The Abutilon Mosaic Virus (AbMV) in Different Leaf Tissues of Several Host Species of Malvaceae

Cytological changes occurring after infection by Abutilon Mosaic Virus (AbMV) have been investigated in the host plants Abutilon sellovianum Rgl., Malva parviflora L., Malva silvestris L., and Sida micrantha Schr. Two types of virus-like inclusions were found in different tissues: particles of 16–18 nm in diameter and elongated filaments with 6–8 nm in diameter. The particles are detectable in the nuclei (Abutilon sellovianum, Malva spec.) and cytoplasm (Malva spec.) of cells in the bundle area, and the filaments accumulate in the nuclei (Sida micrantha) and the plastids (Malva spec.) of leaf mesophyll cells.     

Parasitoid complexes of lepidopteran leaf miners on oaks (Quercus dentata andQuercus mongolica) in Hokkaido,Japan

Parasitoid complexes of four microlepidopteran leaf-mining genera,Phyllonorycter, Caloptilia (Gracillariidae),Tischeria (Tischeriidae) andStigmella (Nepticulidae), which make mines on two oaks,Quercus dentata andQuercus mongolica, were studied at the Ishikari Coast, Hokkaido, northern Japan. In total, twenty-five parasitoid species were recognized.Phyllonorycter showed the highest parasitoid-species richness among the four leaf-mining genera. The number of parasitoid species associated with leaf miners onQ. dentata was nearly equal to that associated with miners onQ. mongolica, but a considerable difference was observed in the faunal make-up of parasitoids between leaf miners on the two oaks. The dominant parasitoid species differed betweenPhyllonorycter leucocorona andPhyllonorycter similis even on the same oak,Q. dentata. Factors influencing the host ranges of parasitoids and the parasitoid richness of host species or genera are discussed on the basis of the koinoparasitism/idioparasitism categorization.     

Detection and Molecular Characterization of Squash leaf curl virus (SLCV) in Jordan

Squash leaf curl virus (SLCV) was detected for the first time in Jordan using degenerated oligonucleotide primers. Two isolates of the virus, SLCV‐E and SLCV‐R, were detected using specific oligonucleotide primers in symptomatic Cucurbita pepo. SLCV was also found to occur naturally in Malva parviflora, which showed severe leaf curling, yellowing and stunting of the whole plants. The full‐length genomes of Squash leaf curl virus‐Malva (SLCV‐Malva) isolate were amplified using the bacteriophage Φ DNA polymerase enzyme. Nucleotide sequence analysis showed that SLCV‐Malva shared high nucleotide identity (98% and 97%) with SLCV‐EG and SLCV‐E from Egypt and USA, respectively. A survey using dot‐blot hybridization indicated that squash leaf curl disease occurred in all surveyed areas. The highest disease incidence (95%) was recorded in Dir Alla area, whereas disease incidence did not exceed 69% in squash samples collected from North Ghor.     

Optimization of the extraction of polyphenols and antioxidant activity from Malva parviflora L. leaves using Box–Behnken design

Abstract

Box–Behnken Design (BBD) was used to optimize the extraction conditions of polyphenols from Malva (Malva parviflora L.) leaves. The effect of ethanol concentration (20–80%), solvent/leaf powder ratio (10:1 to 30:1, v/w) and extraction time (5–45?min) on the polyphenols yield and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the obtained extracts were investigated. Quadratic models fit well. The optimal conditions (53.40% ethanol, solvent/leaf powder ratio 20:1 (v/w), and 15?min) resulted in an extract with a maximum yield of polyphenols (1098.4?mg GAE/100?g leaf powder) and high inhibition percentage of DPPH radical (33.31%) with desirability 0.742. High Performance Liquid Chromatography (HPLC) analysis indicated that the major identified polyphenol compounds extracted at the optimal conditions were naringenin, ρ-coumaric acid, apigenin-7-glucoside, luteolin, and cinnamic acid. These findings indicate that M. parviflora leaf extracts possess DPPH radical scavenging activity and could be used as a natural source for bioactive products.     

The annual species ofAdonis (Ranunculaceae)—a polyploid complex

The five annual species ofAdonis L., sect.Adonis, growing in Israel, form a series of diploid, tetraploid and hexaploid species. Their somatic chromosome numbers are 2n = 16 inA. annua L.,A. dentata Del. andA. palaestina Boiss., 2n = 32 inA. microcarpa DC., 2n = 48 inA. aestivalis L.; counts forA. dentata, A. palaestina andA. microcarpa are new records. There are indications that alloploidization may have been involved in the process of speciation in sect.Adonis. A taxonomic survey of the 8 species of the section reveals that a higher ploidy level is usually combined with a larger distribution area.     

Interactions between a specialist herbivore,Crocidosema plebejana, and its host plantsMalva parviflora and cotton,Gossypium hirsutum: Larval performance

Previous studies have shown populations of tipworm,Crocidosema plebejana Zeller (Lepidoptera: Tortricidae), onMalva parviflora L. persist throughout the development of the plant while those on cotton are greatly reduced after plant flowering. We investigated larval performance of tipworm on plants of both species at various stages of development. Tipworm reared onM. parviflora developed faster, survived better and tended to be heavier than those reared on cotton. OnM. parviflora all parts of the plant were eaten while on cotton large squares, flowers and small to medium bolls were never eaten. Cotton quality for tipworm development decreased markedly at flowering and remained low thereafter, as shown by low survival of neonate larvae and extended development time of late instar larvae. The poor performance of tipworm on flowering cotton is strongly correlated with major changes in plant chemistry at that stage of plant development.     

Leaf photosynthetic and solar-tracking responses of mallow, Malva parviflora, to photon flux density

Malva parviflora L. (mallow) is a species that occupies high-light habitats as a weedy invader in orchards and vineyards. Species of the Malvaceae are known to solar track and anecdotal evidence suggests this species may also. How M. parviflora responds physiologically to light in comparison with other species within the Malvaceae remains unknown. Tracking and photosynthetic responses to photon flux density (PFD) were evaluated on plants grown in greenhouse conditions. Tracking ability was assessed in the growth conditions and by exposing leaves to specific light intensities and measuring changes in the angle of the leaf plane. Light responses were also determined by photosynthesis and chlorophyll fluorescence. Leaves followed a heliotropic response which was highly PFD-dependent, with tracking rates increasing in a curvilinear pattern. Maximum tracking rates were up to 20°h⁻¹ and saturated for light above 1300 μmol (photons) m⁻² s⁻¹. This high-light saturation, both for tracking (much higher than the other species), and for photosynthesis, confirmed mallow as a high-light demanding species. Further, because there was no photoinhibition, the leaves could capture the potential of an increased carbon gain in higher irradiance by resorting to solar tracking. Modelling suggested the tracking response could increase the annual carbon gain by as much as 25% compared with leaves that do not track the sun. The various leaf attributes associated with solar tracking, therefore, help to account for the success of this species as a weed in many locations worldwide.     

Biosynthesis of silver nanoparticles using Malva parviflora and their antifungal activity

Cheeseweed mallow (Malva parviflora L.) was used to biosynthesize silver nanoparticles. The biosynthesized silver nanoparticles were classified by UV–vis Spectroscopy and Fourier-Transform Infrared Spectroscopy (FT-IR). The shape and size distribution were visualized by Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), and Zeta potential analysis. The chemical composition of M. parviflora leaf extract was identified by Gas Chromatography and Mass Spectroscopy (GC/MS). Finally, in vitro antifungal assay was done to assess the potential of biosynthesized silver nanoparticles and crude leaf extract of M. parviflora for inhibiting the mycelial growth of phytopathogenic fungi. The UV–vis analysis manifests the formation of silver nanoparticles. FTIR analysis established that chemicals of the leaf extract stabilized the biosynthesized silver nanoparticles by binding with the free silver ions. The TEM, FE-SEM and zeta potential analyzer confirmed that the biosynthesized silver nanoparticles were mostly spherical with an average diameter of 50.6 nm. The biosynthesized silver nanoparticles and leaf extract of M. parviflora effectively mitigate the mycelial growth of Helminthosporium rostratum, Fusarium solani, Fusarium oxysporum, and Alternaria alternata. The maximum reduction in mycelial growth by biosynthesized nanoparticles was observed against H. rostratum (88.6%). Whereas, the leaf extract of M. parviflora was most effective against F. solani (65.3%). Thus, the biosynthesis of nanoparticle assisted by M. parviflora is a feasible and eco-friendly method for the synthesis of silver nanoparticles. Further the silver nanoparticles and leaf extract of M. parviflora could be explored for the development of the fungicide.     

Do differences in plasticity during early growth lead to differing success in competition? A test using four co‐occurring annual Papaver

Plant species differ in their ability to transform available resources to biomass and to respond in a plastic way to environmental circumstances; we hypothesized that such differences among four weed taxa of Papaver would explain differences in their competitive response. We first compared two populations each of Papaver rhoeas L., P. dubium L. ssp. dubium, P. dubium L. ssp. lecoqii (Lamotte) Syme and P. argemone L., grown in a greenhouse for 6 weeks in a nutrient gradient combined with two light treatments to elucidate possible differences in responses. As there were clear differences, a second experiment evaluated whether these differences also meant differences in competitive response, during early growth, when tested against two crops (wheat, rape). The assumption that competitive response was linked to the ability to transform nutrient and light to biomass was not supported: even though differences in extent of plasticity existed, the effect of competition was similar for the taxa. Thus, higher plasticity and ability to transform available recourses to biomass did not lead to stronger competitiveness for Papaver during early growth.     

Differential effects of host plant hybridization on herbivore community structure and grazing pressure on forest canopies

Interspecific hybridization in plants is known to have ecological effects on associated organisms. We examined the differences in insect herbivore community structure and grazing pressure on tree canopy leaves among natural hybrids and their parental oak species. We measured leaf traits, herbivore community structure, and grazing pressure on leaves of two oak species, Quercus crispula and Q. dentata, and their hybrids. The concentration of nitrogen in canopy leaves was greater in hybrids and in Q. dentata than in Q. crispula. The concentration of total phenolics was lower in hybrids than in Q. crispula. The concentration of condensed tannin was greater in hybrids than in Q. crispula. Relative herbivore abundance and species richness were greater on oak hybrids than on either parental species; herbivore species diversity and composition on hybrids were close to those on Q. crispula. Herbivore grazing pressure was lower on hybrids and Q. dentata than on Q. crispula. There was a negative correlation between herbivore grazing pressure and leaf nitrogen, suggesting that interspecific variation among oak taxa in herbivore pressure may be explained by leaf nitrogen; variation in herbivore community structure among oak taxa is likely to be controlled by polygenic leaf traits. Differing responses of (1) herbivore community structure and (2) herbivore grazing pressure to host plant hybridization may play important roles in regulating herbivore biodiversity in cool‐temperate forest canopies.     

The Ecological Significance of Allelopathy in the Community Organization of Alhagi Graecorum Boiss

Field study revealed that species diversity index of the community was 0.597. The data of interspecific association index of Alhagi graecorum and each of its associates, Chenopodium murale, Glinus lotoides and Malva parviflora, were 0.35, 0.41 and 0.33, respectively. Therefore, a net negative association and low diversity among the species were the main characters of the community. Laboratory experiments verified the role played by competition and allelopathy in this community organization. The bioassay results indicated that A. graecorum exhibited phytotoxic activity on the tested species. Accordingly, water-borne allelopathic compounds may be released from A. graecorum into the environment and suppress the growth of its associates where they were not able to compete with A. graecorum in the field, so the latter species become dominant.     

Cereal weeds variation in middle Egypt: Role of crop family in weed composition

Cereals occupies a major part in the diet of humans globally, participating more to our daily protein and calorie intake than any other crop. The present study highlight the weed flora of cereal crops compared to other crops in middle Egypt and their distribution. Ninety-two weed species were recorded in the all studied crops, cereal and other crops; in the studied area belong to 67 genera and 20 families. Egyptian clover; showed the highest numbers of both weed species and genera followed by wheat, on contrast the lowest weed species and genera numbers were recorded associated with Solanaceous crops tomato and pepper. Wheat crops exhibited the highest number of weed species, among cereals, followed by maize crop, while the lowest weed species number was detected in barley crop. Chenopodium murale, Cynodon dactylon, Convolvulus arvensis and Malva parviflora were the most frequent species in winter cereals, while Echinochloa colona, P. oleraceae were the most frequent weeds in summer cereals. Chorological analysis of the recorded weed species showed that cosmopolitan elements showed the highest numbers in total weed flora Differences in weed species compositions were fundamentally influenced by seasonal priority. Based on TWINSPAN and Ward classifications, crop family showed slightly effect as a factor affecting weed composition.     

The effect of shade on leaf structure and physiology of tree seedlings from a mixed dipterocarp forest

This study builds upon past work investigating seedling leaf physiology and structure among tropical trees. We seek to explain how related and unrelated species and genera co‐occur in relation to varying amounts of shade. Seedlings of eight Sri Lankan rain forest tree species in three genera (Dipterocarpus, Mesua, Shorea section Doona) were grown for 2 years in four treatments that simulated a variety of shade environments across the understorey of a rain forest. All three genera comprise major canopy tree species of mixed dipterocarp forest, a widespread and important Asian tropical forest type. Compared with the other genera, Dipterocarpus spp. had the largest leaves, the thinnest leaf blades and relatively high rates of stomatal conductivity across all shade treatments, making them water‐loving species sensitive to droughty soils. Mesua spp. had intermediate sized leaves, with the thickest leaf blades and palisade mesophyll layers, the highest stomatal densities, the smallest aperture sizes and the lowest rates of stomatal conductance, making them the most water conservative. Shorea spp. were generally intermediate in blade and palisade mesophyll dimensions between Dipterocarpus spp. and Mesua spp., but they had the smallest leaves. Greater differences among genera than among species within genera were apparent, but species differences within genera were also apparent. Differences among genera and species conform to their known successional status and topographical affinities and provide a more comprehensive understanding of species site adaptation. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167 , 332–343.     

Interactions between a specialist herbivore,Crocidosema plebejana,and its host plants Malva parviflora and cotton,Gossypium hirsutum: Oviposition preference

Ovipositional responses of gravid female Crocidosema plebejana Zeller (Lepidoptera: Tortricidae) to all stages of development of its host plants Malva parviflora L. and cotton, Gossypium hirsutum L., were studied in no-choice and choice experiments. In no-choice experiments the site of oviposition and the number of eggs laid reflected the suitability of the host plant for larval survival and development. The same was true of choice experiments although conclusions drawn from these are more tentative due to high levels of heterogeneity. Results from a natural (unplanned) choice experiment in the field, suggested flowering cotton was rejected as a site for oviposition by gravid females. Results from this paper and a previous paper by the authors are combined to explain the failure of tipworm populations to persist on cotton crops after flowering.     

Cytotypes within the family Umbelliferae with special reference to the genera Seseli L. and Oenanthe L. (subtribe Seselinae)

Cytotypes within the genera Seseli L. and Oenanthe L. show variation in chromosome number in pollen mother cells. A correlation of low chiasma frequency with meiotic irregularities and pollen sterility was noted. In addition to the meiotic irregularities in the two genera occurrence of polyspory and triple pollen formation during meiosis have been observed in Seseli diffusum (Roxb.) Sant. Wagh. The presence of different chromosome numbers in different populations of the same species and karyological investigation in 4 species of Oenanthe L. suggests that structural changes of chromosomes associated with numerical differences have possibly played a role in their evolution. Diminution in chromosome size and complete absence of metacentric chromosomes in Oenanthe lachenalli Gmel. suggest that probably this species is more evolved than 3 species of Oenanthe (i.e., O. benghalensis Benth., O. pimpinelloides L. and O. thomsoni Clarke). The interrelationships of the two genera are discussed.     

Pollen Morphology of the Periplocaceae from Madagascar

The pollen morphology of eleven (Baroniella Constantin & Galland, Baseonema Schltr. & Rendle, Camptocarpus Decne., Cryptolepis R. Br., Cryptostegia R. Br., Gonocrypta Baill., Harpanema Decne., Ischnolepis Jum. & H. Perrier, Menabea Baill., Pentopetia Decne., and Tanulepis Balf. f.) of the 13 genera of the Periplocaceae from Madagascar have been examined using light-, scanning-, and transmission electron microscopy. All of the genera are characterized by pollen grains arranged in tetrads. The arrangement of the grains may be rhomboidal, decussate or tetragonal. The 4–6 pores present are restricted to the junction area of adjacent grains. Cryptostegia differs from the other genera in that the arrangement of pollen grains is only decussate. In Menabea the tetrads are united into a pollinium. The exine is smooth and consists of a distal stratum (tectum), subtended by a granular stratum consisting of granules of unequal size. Towards the base larger granules are present. In Camptocarpus, Harpanema and Tanulepis the exine is stratified into a distal stratum (tectum), a thin granular stratum and an almost continuous basal stratum (foot layer). The inline is well developed. The pollen grains of tetrads are connected by wall bridges (cross-wall cohesion). The internal walls in Camptocarpus, Harpanema and Tanulepis differ from the other genera in the absence of a tectum. The pollen morphology of the taxa investigated is very similar and of little value for distinguishing the species and genera investigated. The distinctive difference in exine structure between the above mentioned three genera and other genera investigated emphasizes the importance of exine ultrastructure in the Periplocaceae.     

VIABILITY OF SEEDS UP TO 211 YEARS OLD EXTRACTED FROM ADOBE BRICK BUILDINGS OF CALIFORNIA AND NORTHERN MEXICO

Seeds recovered from adobe walls of historic buildings in California and Northern Mexico were assayed for viability and germinability. Seven of the approximately 40 species tested had one or more viable seeds. These were (age of seeds in parentheses) Medicago polymorpha (200), Malva parviflora (200, 195, 183), Hordeum leporinum (200), Trifolium sp. (193), Melilotus indicus (183), Chenopodium murale (183), and C. album (143). Additionally, 41-yr-old seeds of Lotus corniculatus collected from living plants were found to be viable. Seeds of Medicago polymorpha and Lotus corniculatus germinated and produced normal seedlings. The importance of seed longevity in weedy species is briefly discussed.     

Systematic implications of flavonoid pigments in the fern genus hemionitis (adiantiaceae)

The closely related fern generaHemionitis L. andGymnopteris Bernhardi are separated primarily on differences in leaf architecture and venation. Studies indicate that these characters are highly variable and unreliably diagnostic. Further, the type species of the two genera readily hybridize with each other. Spore morphology, as exhibited by SEM, does not support the traditional alignment of the species in these two genera: some species ofHemionitis andGymnopteris have the same rugose to papillate spores, while other species from both genera possess crested spores. The flavonoid chemistry of these taxa coincides with spore type, i.e., taxa from both genera which possess crested spores produce kaempferol and quercetin 3-0-glycosides, while species with tuberculate spores produce only quercetin 3,4′-0-glycosides. The spore and chemical data suggest a realignment of these taxa within a single genus, which would avoid the rather tenuous dependence on a single vegetative character for generic distinctions.