Lower Leaf Surface Research Articles

Rust Disease of Aster pilosus Caused by Coleosporium asterum in Korea

Aster pilosus Willd. [syn. Symphyotrichum pilosum (Willd.) G.L.Nesom var. pilosum ], commonly known as frost aster or white heathaster, is a perennial plant belonging to the Asteraceae. This plant isnative to North America and was introduced into Korea during theKorean War in the 1950s (Park, 1995). It is now widely naturalizedand officially designated as one of 11 ‘harmful non-indigenousplants’ by the Korean Ministry of Environment. Since 2004, fromJune to November, severe occurrence of rust infections has beenconsistently observed on plants growing wild in Korea. Examinationof a typical plant revealed yellow-orange rust pustules wereproduced on the stem and lower leaf surface with correspondingsmall yellowish to chlorotic lesions on the upper surface (Figs 1A &.1C). No symptoms were observed on flowers. Both the cauline andradical leaves were equally susceptible to the pathogen. Severeinfections often resulted in leaf distortion, withering and prematuresenescence (Fig. 1B). More than 20 voucher specimens have beendeposited in the herbarium of Korea University (KUS).Uredinia were mostly hypophyllous, yellow-orange, erumpent,and 90–150 µm in diameter (Fig. 1D). Urediniospores were sub-globose to ellipsoid, but somewhat irregular and variable in shape,yellow-orange,ver rucose, 22.5–32.5 × 17.5–20 µm i,ncluding 2 µmin wall thickness (Figs. 1E–1H). No telial stage was found. Thisspecies is supposed to overwinter in the uredinial state in Korea.Based on the morphological characteristics, the rust pathogen wasidentified as Coleosporium asterum (Dietel) Syd. & P. Syd., asdescribed by Hiratsuka et al. (1992).Genomic DNA was extracted from urediniospores of the driedherbarium specimens (KUS-F23395, 24985, 25002). The D1/D2region of 28S rDNA was amplified using the primers LROR andLR6, and directly sequenced. The resulting sequences of the threespecimens were identical to each other, and have been deposited inGenBank with accession numbers (JF273968–JF273970). A NCBIBLAST search showed that the present sequences had 99%similarity to those of Coleosporium asterum on Aster sp. andSolidago sp. In the phylogenetic tree (Fig. 2), inferred usingneighbour-joining method in MEGA4, the Korean isolates and C.asterum formed a monophyletic clade with moderate bootstrapvalue. C. asterum on A. pilosus has been reported from Canada and theUnited States (Farr and Rossman, 2011). This is the first recordoutside of North America, as well as in Korea, for a rust infection onA. pilosus caused by C. asterum . This rust fungus has been reportedto produce spermogonial and aecial stages on Pinus densiflora(Hiratsuka et al., 1992). However, its occurrence has not beenconfirmed in Korea. Our observations suggest that the rustinfections markedly suppress the growth of this noxious weed andecologically retard the spread and expansion to the naturalenvironment. This rust fungus may thus have the potential to besuccessfully exploited as a biocontrol agent for the weed.

<i>Neotropacarus bakeri</i> (Collyer, 1967) rediscovered (Sarcoptiformes: Acaridae)

Systematic & Applied Acarology entered a new chapter in its development in 2011 (Zhang 2011), including the introduction of a colour cover which has received positive responses from authors and readers. To continue this, we invite authors to send us good colour images of mites for consideration of publication on the cover. There is no fee for publication of cover images and this presents an excellent opportunity for authors as colour images are normally expensive and difficult to publish elsewhere. From this issue, we initiate a series of short correspondence for the story behind the cover image. We welcome future authors to submit a paragraph or two about the images. The images featured on the cover of this issue show the interesting clustering behaviour of Neotropacarus bakeri (Collyer, 1967) on leaves of karaka (Corynocarpus laevigatus; Corynocarpaceae) in Auckland, New Zealand. This mite species was first described by Collyer (1967), but there have been no subsequent reports since. Collyer (1967) reported this mite from 16 species of plants in the north of the South Island and also various parts of the North Island. The record from karaka is a new host record. Collyer (1967) noted that this species “lives in compact colonies comprising a central cluster of eggs surrounded by immatures and adults orientated with their bodies facing inwards” (see cover images). Her observations—that these mites “are usually on the ventral leaf surface, often in slight hollows, and the groups are widely scattered”—are confirmed in this study. It was also observed that wandering immature mites and adults, when placed on a new leaf, formed new clusters on the lower leaf surface. Cunliffe (1964) stated that the type species of this genus, N. mumai, is fungivorous. We also observed N. bakeri breeding on fungi cultured on PDA inoculated with small pieces of karaka leaves. Acknowledgements. I thank Dr Nick Martin (Landcare Research, Auckland) for collecting the karaka leaves on which N. bakeri was rediscovered, Dr Qinghai Fan (Ministry for Primary Industries, Auckland) for identifying the mite species and Dr Owen Seeman (Queensland Museum, Australia) for comments.

Composition and Physiological Function of the Wax Layers Coating Arabidopsis Leaves: β-Amyrin Negatively Affects the Intracuticular Water Barrier

Plants prevent dehydration by coating their aerial, primary organs with waxes. Wax compositions frequently differ between species, organs, and developmental stages, probably to balance limiting nonstomatal water loss with various other ecophysiological roles of surface waxes. To establish structure-function relationships, we quantified the composition and transpiration barrier properties of the gl1 mutant leaf waxes of Arabidopsis (Arabidopsis thaliana) to the necessary spatial resolution. The waxes coating the upper and lower leaf surfaces had distinct compositions. Moreover, within the adaxial wax, the epicuticular layer contained more wax and a higher relative quantity of alkanes, whereas the intracuticular wax had a higher percentage of alcohols. The wax formed a barrier against nonstomatal water loss, where the outer layer contributed twice as much resistance as the inner layer. Based on this detailed description of Arabidopsis leaf waxes, structure-function relationships can now be established by manipulating one cuticle component and assessing the effect on cuticle functions. Next, we ectopically expressed the triterpenoid synthase gene AtLUP4 (for lupeol synthase4 or β-amyrin synthase) to compare water loss with and without added cuticular triterpenoids in Arabidopsis leaf waxes. β-Amyrin accumulated solely in the intracuticular wax, constituting up to 4% of this wax layer, without other concomitant changes of wax composition. This triterpenoid accumulation caused a significant reduction in the water barrier effectiveness of the intracuticular wax.

Morphological characteristics and chromosome behaviour in F1, F2 and BC1 progenies between Chrysanthemum × morifolium and Ajania pacifica

The garden chrysanthemum (Chrysanthemum x morifolium) variety 'Aoyunhuoju' (2n = 6x = 54) was crossed as female with Ajania pacifica (2n = 10x = 90) to produce an intergeneric F1 hybrid, which was used both as a source ofF2 progeny and as a parent for a first back-cross with 'Aoyunhuoju'. The morphology of all of the F1 hybrids and hybrid derivatives was intermediate with respect to the two parents, although the BC1 progenies resembled 'Aoyunhuoju' more closely than any of the F1 and F2 progenies did. In the F1 hybrid, the density of silvery hairs on the lower leaf surface and along the margin of the leaf was lower than in A. pacifica, while that in the BC1 generation, this trait was less prominent than in the F1. The somatic chromosome number of the F1, F2 (with an exception of F2-6 of a mainly 63) and BC1 generations was 2n = 8x = 72, 2n = 8x = 72 and 2n = 7x = 63 respectively, as expected. The hybrids and their derivatives retained a variable degree of fertility. There was a low frequency of meiotic chromosome pairing failure in all three hybrid generations, with most of the chromosomes involved as bivalents. Some BC1 individuals show potential for commercialization thanks both to their flower shape and the inheritance of the silvery leaf trait from A. pacifica.

First Report of Cladosporium Leaf Spot of Spinach Caused by Cladosporium variabile in the Winter Spinach Production Region of California and Arizona.

In December 2011, symptoms typical of Cladosporium leaf spot caused by Cladosporium variabile (4) were observed in organic "baby leaf" spinach (Spinacia oleracea) crops of the cultivars Amazon, Missouri, Tasman, and Tonga in the Imperial Valley (Imperial County, CA and Yuma County, AZ). Leaves had small, circular lesions (1 to 3 mm in diameter), some of which had progressed to necrotic, bleached lesions surrounded by a thin dark margin. The incidence of symptoms in affected crops was ≤20%. Fungal isolates resembling C. variabile were recovered by surfacesterilizing sections (5 mm2) of symptomatic leaf tissue in 0.6% NaOCl, triple-rinsing the sections in sterile water, and plating the sections onto water agar and potato dextrose agar amended with 100 ppm chloramphenicol (cPDA). Single-spore transfers made onto cPDA were maintained at 24 ± 2°C with a natural day/night cycle. Each isolate produced slow growing cultures consisting of dense masses of dark conidiophores (≤350 μm long) with chains of up to three dematiaceous (olive) conidia, and almost no mycelium. Torulose (coiled) aerial hyphae developed from the apices of conidiophores after 5 to 7 days, and distinguished the isolates as C. variabile, not C. macrocarpum (2,4). Pathogenicity was tested for each of six single-spore isolates using 36-dayold plants of the spinach cultivar Carmel. The plants were enclosed in clear plastic bags overnight and inoculated the next day with the isolates of C. variabile by atomizing approximately 30 ml of a spore suspension (1.0 × 106 conidia/ml in sterile water amended with 0.01% Tween 20) of the appropriate isolate onto the upper and lower leaf surfaces of each of five plants/isolate. Five control plants were inoculated similarly with sterile water + 0.01% Tween 20. The plants were resealed in plastic bags for 72 h and then placed on a greenhouse bench. Pinpoint, sunken lesions developed within 4 to 7 days on the leaves of plants inoculated with each of the six test isolates. Lesions developed into dry, circular spots typical of Cladosporium leaf spot. Symptoms were not observed on control plants. After 20 days, C. variabile was reisolated from lesions caused by all six isolates, but not from control plants. Although Cladosporium leaf spot has been reported in the Salinas Valley of California (4), to our knowledge, this is the first report of the disease on spinach crops in the Imperial Valley of California and Arizona, the primary winter, fresh market spinach production region of the United States. Inoculum of C. variabile may have been introduced to this region on spinach seed lots (3), because even seed infestation levels <0.1% could lead to seed transmission (1) under the dense planting populations (≤9 million seeds/ha) and overhead irrigation typical of "baby leaf" spinach crops in this region. Fungicides can be used to manage Cladosporium leaf spot in conventional spinach crops (1), but management in certified organic crops may be more challenging.

Infraspecific classification ofAlyssum diffusum (Brassicaceae)in Italy

Spaniel S., Zozomová-Lihová J., Passalacqua N. G. & Marhold K.: Infraspecific classification of Alyssum diffusum (Brassicaceae) in Italy. — Willdenowia 42: 37–56. June 2012. — Online ISSN 1868-6397; © 2012 BGBM BerlinDahlem. Stable URL: http//dx.doi.org/10.3372/wi.42.42104Recent studies of the Alyssum montanum-A. repens complex in Europe showed that populations from central and southern Italy are, in contrast to previous taxonomic treatments, clearly distinct from A. montanum and should be classified as A. diffusum. Based on the high, geographically structured genetic variation (central Apennines, Gargano, and southern Apennines/Calabria) of A. diffusum, three subspecies were recently recognised. Here, we present a detailed morphometric study of A. diffusum in Italy, exploring its differentiation from A. montanum and differentiation among the three subspecies (A. diffusum subsp. diffusum, subsp. garganicum and subsp. calabricum). We report that A. diffusum differs from A. montanum subsp. gmelinii particularly by having (on average) larger flower parts and from subsp. montanum by a different density and morphology of trichomes and narrower petals. The subspecies of A. diffusum can be distinguished by the number of trichome rays, by trichome density on the lower leaf surface and by the leaf length. In this study, we present an identification key that includes the subspecies of A. diffusum, those of A. montanum and the related A. cuneifolium. We also provide detailed morphological descriptions of all three subspecies of A. diffusum and a nomenclatural account, including the designation of the lectotype of the name A. diffusum.

The systematic and palaeoecological value of foliage anatomy in Late Palaeozoic medullosalean seed-plants

This paper reviews the anatomical evidence of medullosalean foliage known from cuticles and coal balls, and discusses what it tells us about the systematics and palaeoecology of the parent plants. Medullosalean foliage shows more diversity in epidermal anatomy than in any other group of gymnospermous seed-plants, especially in the configuration of subsidiary cells around the stomata, the detailed structure of the hairs, and the shapes of the cells. Diagnostic for the order are the fronds typically having dorsiventral pinnules supported by rachises with a dissected stele, resin canals in both rachises and pinnules, and distinctive epidermal hairs consisting of a single row of many cells. Foliage anatomy is of little value for distinguishing medullosalean families but is useful for distinguishing genera and species. Anatomy also provides insights into the autecology of the plants. A number of features previously regarded as xeromorphic are re-interpreted as adaptations to high-humidity conditions (stomata sunken or protected by papillae, papillae on lower surface of leaf). Different species could grow in either shaded or well-illuminated positions, indicated by the absence or presence of a hypodermis below the upper epidermis. Few species show evidence of defensive strategies against herbivory except possibly in juvenile fronds. Evidence from stomatal distribution and structure for determining variation in atmospheric CO2 is equivocal but may indicate a rise in CO2 levels in early Stephanian (latest Moscovian) times.

Morphological and chemical characteristics of tomato foliage as mechanisms of resistance to Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae

Morphological characters and chemical composition of tomato ( Lycopersicon esculentum Miller) leaves were measured and compared among nine tomato varieties (Roma VFN, NARC-1, Fs-8802, Tommy, Pant Babr, Rio Grande, Nova Mecb, Pakit and Sahil) exhibiting varying levels of host plant resistance to Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) as based on fruit infestation. The variety, Sahil, was resistant, whereas Roma VFN was the susceptible variety. Hair length and hair density on lower leaf surface, as well as thickness of leaf lamina significantly correlated with larval population and fruit infestation. Leaf hair density accounted for 92.0% of the variation in fruit infestation and 77.0% of the variation in larval population. Ferrous (Fe 2+ ) and phosphorous content in the leaves were negatively correlated with fruit infestation and larval population; whereas, nitrogen, calcium, magnesium, manganese and zinc content were positively correlated with fruit infestation and larval population. The resistant variety, Sahil, produced the maximum yield as compared to susceptible variety, Roma VFN. Keywords: Helicoverpa armigera , tomato fruit borer, host plant resistance, Lycopersicon esculentum

First Report of Black Swallow-Wort as an Alternate Host of the Two-Needle Pine Stem Rust Pathogen, Cronartium flaccidum, in France.

Stem rust disease, caused by Cronartium flaccidum (Alb. & Schwein.) G. Winter, is among the most destructive diseases of the two-needle hard pine in the Northern Hemisphere, including Scots pine but also several Mediterranean pines in southern Europe (2,3). This heteroecious rust has numerous alternate herbaceous hosts spanning different plant families, thereby contributing to epidemic outbreaks when environmental conditions for infection are optimal (2,3). The main alternate host in Europe is the white swallow-wort, Vincetoxicum hirundinaria Medik, a herbaceous perennial in the milkweed family (Asclepiadaceae). At the southwestern edge of its distribution, V. hirundinaria co-occurs with the black swallow-wort, V. nigrum (L.) Moench and cases of misidentification between the two species are not uncommon. Little to no disease occurs to V. nigrum likely because phenanthroindolizidine alkaloid antimicrobial compounds are produced in the weed. In 1918, occurrence of C. flaccidum was reported in Spain and Portugal on black and white swallow-worts albeit as C. asclepadium (1). In the early summer of 2011, at Saint Clément de Rivière in southern France, we detected orange-yellow rust pustules on the lower leaf surfaces of several black swallow-worts growing near Aleppo pines (Pinus halepensis). These orange-yellow pustules were erumpent uredinia in groups (range = 137 to 400 μm in diameter) with peridia that broke with the production of uredinospores. The latter were moderately echinulate, light yellow, broadly ellipsoid (length = 23 ± 4 μm and range = 11 to 33 μm; width = 15 ± 2 μm and range = 9 to 20 μm) with walls of 1 to 2 μm thick (mean 1.3 ± 0.2 μm). Hair-like columnar telia (length = 1123 ± 131 μm and range = 976 to 1280 μm; width = 136 ± 28 μm and range = 104 to 176 μm) were mostly formed from uredinia. Telia were hypophyllous and reddish orange. Teliospores were orange-yellow and ellipsoidal to cylindrical (length 26.3 ± 6.2 μm and range 13.5 to 46 μm; width = 10.5 ± 1.8 μm and range = 6.9 to 14.9 μm). Morphological features of these fruiting structures were consistent with those of C. flaccidum (Alb. & Schwein.) G. Winter on white swallow-worts (2). Additional confirmation was provided by sequencing the two internal transcribed spacer regions (ITS1 and ITS2) and the 5.8S gene (4). The sequence was 843 bp long (GenBank Accession No. JN802139), 99.7% similar to C. flaccidum found on Melampyrum in Finland (Accession No. JF13709), and 99.4% similar to C. flaccidum found on pines in Italy (Accession No. X83900). Voucher material has been deposited at the Herbarium of Montpellier's University under the collection Accession No. MPUØ188846. To our knowledge, this is the first report of the occurrence of uredinia and telia of C. flaccidum on black swallow-worts clearly identified in France. The occurrence of the rust on this understory vine is of critical importance for the economic sustainability of pine forests in France, especially when they are heavily constrained by drought and fire.

Powdery Mildew of Pterocarya stenoptera Caused by Phyllactinia juglandis in Korea

Chinese wingnut (Pterocarya stenoptera DC.), belonging to theJuglandaceae, is native to Southeast China and is now widely-planted for ornamental purposes in Korea and Japan. In September2010, powdery mildew infections were first noticed in a privategarden in Suwon, Korea. The lower surfaces of the damaged leaveswere covered with conidia and conidiophores of a powdery mildewfungus (Fig. 1A). Mature chasmothecia were abundantly formed byNovember (Fig. 1C). Voucher specimens have been deposited atKorea University, Seoul, Korea (KUS-F25487, F25618). Detailed microscopic examination was made to identify thepathogen. Mycelia were hypophyllous, rarely epiphyllous in heavilyshaded areas (Fig. 1B), thinly effused, initially forming patches,finally covering the whole lower leaf surface. Hyphal appressoriawere nipple-to r od-shaped, often branched, and single or opposite inpairs. Conidiophores were unbranched, 150–280 × 6–8 µm, straightin foot-cells, producing conidia singly, followed by 2–3 cells (Figs.1D and 1E). Conidia were obpyriform to clavate, papillate at theapex, 45–72 × 18–28 µmand devoi , d of distinct fibrosin bodies (Fig.1F). Chasmothecia were scattered, 180–260 µm in diameter, blackishbrown, and depressed globose. Appendages were 8–16 in number,arising around the equatorial zone of the chasmothecia, simple,acicular with a bulbose base, 26–45 µm wide at the ball, 9–12 µmwide above the ball and gradually narrower upwards, 1.2–1.6 timesas long as the chasmothecial diameter, hyaline throughout, andaseptate (Fig. 1G). Penicillate cells were crowded on the upper partof the chasmothecia, 30–90 µm long, 8–20 µm wide, bifurcate ordivided into 2–6 branchlets in the upper part, with filaments 20–70µm long (Fig. 1I). Asci were 8–20 in a chasmothecium, olivace-ous brown, 60–90 × 30–40 µm, and shortly stalked. Ascosporeswere 2 in an ascus, oval, light brown to golden brown, 28–45 × 17.5–25 µm (Fig. 1H). The morphological characteristics fit well with theprevious descriptions of Phyllactinia juglandis J.F. Tao & J.Z. Quin(Braun, 1987; Shin and Lee, 2002; Tao et al., 1977).To confirm the identification of the fungus, the genomic DNAwas extracted from the material of KUS-F25618. Amplification anddirect sequencing of the complete internal transcribed spacer (ITS)region of rDNA were performed using the primer set ITS5 and P3according to the modified method of Takamatsu et al. (2008). Theresunitlg sequence was deposietd in GenBank (JF460007 A BL). ASTsearch against GenBank database showed that it shares a highdegree of similarity (99%) to the ITS sequences of Phyllactiniajuglandis. To illustrate the phylogenetic placement of the causalfungus within the genus Phyllactinia, a neighbor-joining tree wasconstructed using MEGA4 (Fig. 2). The powdery mildew diseases of Pterocarya spp. have beenrecorded to be associated with P. juglandis from China and Japan(Braun, 1987; Takamatsu et al., 2008; Tao et al., 1977). To ourknowledge, this is the first record of Phyllactinia infections on P.stenoptera in Korea. This work also provides the first ITS sequencesof P. juglandis ex Pterocarya stenoptera and confirms this host-parasite combination.

A Remarkable New Species of &lt;I&gt;Jarandersonia&lt;/I&gt; (Malvaceae-Brownlowioideae) from Central Kalimantan, Borneo

A new species, Jarandersonia pentaceoides (Malvaceae-Brownlowioideae), endemic to central Kalimantan, Borneo is described and illustrated. Salient morphological features of the new species that can be used to distinguish it from previously known species of the genus (i.e. J. clemensiae, J. parvifolia, J. purseglovei, J. rinoreoides and J. spinulosa) are tabulated. These include: the densely stellate-lepidote and dentate-lepidote edges of tertiary veins and honeycomb-like quaternary veins on the lower leaf surface, the kneed petiole that is swollen at both ends, and the sparsely stellate-lepidote and tufted-hairy seed coat. A key to the species of Jarandersonia is provided, as is a map of its distribution. Keywords—Borneo, endemic, flora, Jarandersonia, Malvaceae-Brownlowioideae, taxonomy. Jarandersonia Kosterm. (Malvaceae-Brownlowioideae) was established as a monotypic genus by Kostermans (1960) based on Jarandersonia paludosa Kosterm. (currently a synonym of Jarandersonia purseglovei (Kosterm.) Kosterm.), an endemic species that occurs in Sarawak, Borneo. Kostermans (1960, 1970) recognized the genus based on the distinctness of its fruit covered with slender spines bearing setose hairs. It com- prises five species distributed in Borneo (Kostermans 1970). Jarandersonia purseglovei and J. spinulosa Kosterm. are endemic to Sarawak, J. rinoreoides Kosterm. is endemic to Sabah, while the other two species J. clemensiae (Burret) Kosterm. is known from Sarawak and Kalimantan, and J. parvifolia Kosterm. occurs in Sarawak, Brunei and Kalimantan. Recent phylogenetic analy- sis of plastid atpB, rbcL and ndhF DNA sequences support the placement of Jarandersonia, together with Brownlowia Roxb., Diplodiscus Turcz. and Pentace Hassk. in the Brownlowioideae clade of Malvaceae s. l. (Judd and Manchester 1997; Alverson et al. 1999; Bayer et al. 1999; Nyffeler and Baum 2000). The author's recent revision of the genus for the Tree Flora of Sabah and Sarawak Project recognized six species of Jarandersonia from Borneo. Of these, J. pentaceoides, endemic to central Kalimantan, is new to science and is here described for the first time as a precursory paper to the publication of the revi- sion for the genus.

Two new species and a new combination of Neotropical Sapotaceae

This paper provides descriptions and illustrations of two new species of Sapotaceae (Pradosia longipedicellata and Chromolucuma apiculata) from Bahia, Brazil, a new combination (Chromolucuma congestifolia), and a new identification key for Chromolucuma. Pradosia longipedicellata is distinguished from other congeners by its clustered fascicles of flowers on pedicels 2–3 cm long at the apices of the shoots, and a corolla that is 7–8 mm long. Chromolucuma apiculata is distinguished by glabrous shoots and leaves, short petioles (10–15 mm long), and stipules 5–8 mm long with apiculate apices, while its close relative C. congestifolia has a lower leaf surface with trichomes usually restricted to the midrib and stipules 3–6 mm long with acute apices. Due to intense deforestation in the Amazonian and the Atlantic forests, preliminary IUCN Red List assessments are provided. Pradosia longipedicellata and Chromolucuma congestifolia are proposed the IUCN status Vulnerable, while the data for C. apiculata are still insufficient (Data Deficient).

Hyperspectral leaf signature as an added dimension for species discrimination: case study of four tropical mangroves

Hyperspectral leaf reflectance of a plant provides unique information that is characteristic of that plant. The present investigation is a preliminary attempt to assess whether spectra of leaves of mangrove species recorded under field conditions contain adequate spectral information for discerning mangroves at species rank. The paper highlights the hyperspectral characteristics of leaf surfaces of four prominent tropical mangrove species, viz., Avicennia alba, Avicennia marina, Rhizophora mucronata and Sonneratia caseolaris, found in the tidal forests of India. Hyperspectral observations were recorded using a field spectroradiometer, and pre-processed and averaged reflectance values of samples for three types of arrangements, viz., (1) randomly arranged leaves, (2) dorsal leaf surfaces and (3) ventral leaf surfaces of the species were statistically tested using one-way ANOVA to see whether the values significantly differed at every spectral location. All the four species were statistically different at all the spectral locations with majority of the bands exhibiting 99% confidence level. Finally, discriminant analysis was performed to identify the bands for maximum separability for the three types of arrangement of the leaves of the species taken separately and in different combinations. The optimal Wilks’ Lambda (L) were achieved with: six, three, eleven, six, five, thirteen and eleven wavelengths for discriminating random leaves of the four species, dorsal and ventral surfaces of A. alba, A. marina, R. mucronata, S. caseolaris, upper leaf surfaces of all the species, lower leaf surfaces, respectively. Factor analysis was used as an added tool to identify the wavelengths that were uncorrelated and contained maximum information in the combination of selected wavelengths. The results confirmed the unique spectral signatures of the four species, which could be explained in terms of leaf properties unique to the species. Cellular structure and pigmentation of the isolateral leaves of S. caseolaris are very different from the dorsiventral ones of the other three, which significantly changed the reflectance characteristics of the species.

Comparative spray deposits by manually pulled trolley sprayer and a spray gun in greenhouse tomato crops

The aim of this work was to evaluate spray deposition and losses to the soil in a greenhouse tomato crop during the use of a manually pulled trolley, equipped with two vertical spray booms, each with four nozzles spaced 0.50 m apart and oriented 15° upwards, in comparison with a reference treatment with a manual spray gun. The test conditions for the spray gun were established taking into account the routine practiced by farmers, consisting of treating high crops at spray volumes of nearly 1500 l ha −1 at pressures of about 2000 kPa. For the trolley, two types of nozzles were tested (standard flat fan nozzles and air-induction flat fan nozzles), at a pressure of 1200 kPa, distributing approximately the same volume as with the spray gun. Artificial targets (strips of filter-paper) fixed to upper and lower leaf surfaces in 12 zones of the tomato plants (3 heights and 4 depths) were used to collect deposits of the tracer Tartrazine. The results indicated that the deposits with the spray trolley were significantly greater than those with the spray gun. The trolley resulted in an overall deposition 40.6% and 33.9% greater than with the gun, using the standard flat fan nozzles and air-induction flat fan nozzles, respectively. Also, the spray boom reduced losses to the soil by roughly 54% compared to the spray gun. With respect to the tests made with the manually pulled trolley, the results show that the standard flat fan nozzles and air-induction flat fan nozzles behaved similarly. No significant differences were found between nozzles in the mean deposition on the canopy nor in losses to the soil.

First Report of Rust Caused by Puccinia psidii on Paperbark, Melaleuca quinquenervia, in California.

Infections by Puccinia psidii Winter were detected on Melaleuca quinquenervia (Cav.) Blake (paperbark, tea tree) during a regular inspection of a San Diego, California nursery in November 2010 by San Diego County inspectors. Urediniospore morphology, production of bright-yellow uredinia on both upper and lower leaf surfaces, DNA sequencing, and inoculation tests confirm the identity of the pathogen. From digital image analysis, dimensions of 49 urediniospores from the paperbark rust collection were 25 (19 to 30) × 21 (18 to 23) μm, typical of uredinia of P. psidii (3). Some urediniospores also had a distinctive, unornamented "tonsure" near the base, and all pustules lacked teliospores. Both latter features are considered by some (3) as more typical of an asexual sub-taxon, Uredo rangelii Simpson, Tho., Grgur. which however, has narrower urediniospores than we report. U. rangelii is also considered less of a threat to Eucalyptus than other variants of P. psidii in the broad sense (1). The 627-bp DNA sequence of the internal transcribed spacer (ITS) region of the paperbark rust (GenBank Accession No. JF960255) obtained by John Hanna at the USDA Forest Service, Forestry Sciences Lab, Moscow, ID using PCR and ITS1/ITS4 primers had over 99% identity with 18 GenBank sequences of P. psidii from diverse Myrtaceae, including Melaleuca, Psidium, and Eucalyptus. In January and February of 2011, inoculations of 7- to 10-cm cuttings of active terminal growth demonstrated pathogenicity to the three species of Myrtaceae that were tested: paperbark, common myrtle Myrtus communis L., and brush cherry Syzygium australe (J.C. Wendl. ex Link) B. Hyland (=Eugenia australis, =E. myrtifolia) cv. Monterey Bay. Uredinia developed within 10 days of inoculation on inoculated host cuttings. Proportions of cuttings infected for paperbark, common myrtle, and brush cherry were 5 of 7, 6 of 6, and 1 of 6, respectively; pustules were most abundant on common myrtle and least abundant (a single pustule) on brush cherry. Similarly treated control cuttings were not infected. P. psidii has previously caused severe outbreaks on paperbark in Florida (2). California interceptions and nursery detections of P. psidii are recorded in the California Department of Food and Agriculture's internal, unpublished, Pest Detection Database, have all occurred since 2003, and include Florida sources. From the Database, detections on materials shipped into California nurseries have been: brush cherry from Florida, March and April, 2004 at Valley Center, CA; allspice (Pimenta dioica (L) Merr.) from Florida, June 2005 at Gilroy, CA; and Java apple/rose apple (Syzygium samarangense [Blume] Merr. & L.M. Perry [= Eugenia javanica Lam.]) from Hawaii, 2008 at Anaheim, CA. Other California nursery infestations have been: brush cherry, April 2004, at Valley Center, CA; pohutukawa (Metrosideros excelsa Solander ex J. Gaertner), July 2007 at Bonsall, CA; and common myrtle, November 2008 at Fallbrook, CA. The rust has not been reported in California on any plants outside of nursery settings or on Eucalyptus in any setting. The current strains of P. psidii in California appear likely to remain a recurrent problem for ornamental plant and foliage crops in the myrtle family grown in some nursery settings.

New eriophyoid mites (Acari: Prostigmata: Eriophyoidea) from banana and heliconia in Northeastern Brazil—two new genera and three new species

A new genus and new species of the mite family Eriophyidae (Phyllocoptinae), namely Cothrix erugata n. sp. et n. gen., is described from Heliconia stricta Huber (Heliconiaceae). In addition, one new genus and two new species of Diptilomiopidae, namely Rhyncadicrus asperulus n. sp. et n. gen. from banana, Musa acuminata Colla x Musa balbisiana Colla (genomic group AAB) (Musaceae) and Catarhinus granatus n. sp. from Heliconia bihai L., are described and illustrated. The mites were collected in the State of Pernambuco, Northeastern Brazil. All were vagrants on the lower leaf surfaces of their host plants and no visible damage symptoms were observed.

Problems with the taxonomy of Phytoptus tetratrichus Nalepa 1890 (Acari: Eriophyoidea) inhabiting Tilia spp.: Analysis based on morphological variation among individuals

The purpose of this research was to investigate both the qualitative and quantitative morphological traits of Phytoptus tetratrichus Nalepa 1890 populations inhabiting three different lime tree species: Tilia cordata Mill., Tilia tomentosa Moench and Tilia americana L.. Morphological characters of two populations collected from T. cordata and T. tomentosa over three successive growing seasons were compared with the aid of canonical variate analysis. Additionally, individuals occurring on T. americana in a consecutive year were also studied. Protogyne and deutogyne females were differentiated using both qualitative and quantitative traits. For deutogyne females, individuals from all combinations of Tilia species × year (which constituted populations for comparison) clearly differed from each other. However, the differences between populations from T. cordata and T. tomentosa were less distinct. For protogyne females, observed differences were clearly visible. The between-season variation in morphological characters such as body size appeared to be quite large, indicating that morphological analysis based on observations from only a single season can be inaccurate. Deutogyne females of P. tetratrichus were observed to cause various types of damage symptoms: leaf-roll galls along the leaf edges of T. cordata; small round erinea on the lower leaf surface and small wart-like galls on the upper leaf surface of T. tomentosa; fingerlike galls on both leaf surfaces of T. americana.

First Report of Pseudoperonospora cubensis on Cucurbita moschata in the Czech Republic.

Pseudoperonospora cubensis (Berk. & M.A. Curtis) Rostovzev, the causal agent of cucurbit downy mildew, was observed for the first time on Cucurbita moschata Duchesne in the Czech Republic (CR) in August 2009 and repeatedly in September 2010. Recently, C. moschata has not been an economically important crop in the CR; however, related crops C. pepo and C. maxima have increased in importance. Infected plants with P. cubensis were found in two locations: in a hobby garden in north Moravia (Nový Jičín - Kojetín [49°33'48.088″N, 17°59'16.632″E], 2009 and 2010) and in a commercial field in central Moravia (Olomouc-Holice [49°34'31.95″N, 17°17'35.462″E], 2010). The pathogen caused small, angular, yellowish or pale green lesions on the upper leaf surfaces and produced sporangiophores and sporangia on the lower leaf surfaces. The lesions were delimited by leaf veins and later turned necrotic. Sporangiophores were hyaline, branched, and emerged in groups from stomata. Olive brown-to-dark brown sporangia were ellipsoidal to oblong. Our morphological observations confirmed that the pathogen was P. cubensis (2). No previous reports are available of P. cubensis on C. moschata in CR or anywhere in Central Europe. However, P. cubensis is common on C. moschata in some parts of Asia and the United States (1,2). P. cubensis exhibiting clear host specialization has been reported in different countries and geographic areas (2). A C. moschata isolate (PC 88/2009) originating from the naturally infected plants was inoculated (1 × 105 spores per ml and incubation temperature of 18/15°C during light/dark cycles) according to the methodology described by Lebeda and Urban (3) onto the abaxial surface of leaf discs of all genotypes of a differential set of cucurbits for P. cubensis pathotype determination (4). C. moschata (line Novo5, Nohel-Garden, CR) was added to this set. The isolate PC 88/2009 was highly pathogenic to all screened Cucurbita spp. genotypes (C. pepo, C. maxima, and C. moschata). However, no infection was detected on most of the Cucumis accessions; only Cucumis melo subsp. agrestis var. conomon was susceptible. Also, no infection was observed on other differentials (Citrullus, Benincasa, Luffa, and Lagenaria). The pathotype was classified as Pc 4/15/0. This pathotype had not been previously detected in CR.

Micro-morphological alterations in young rosette leaves of Dipsacus laciniatus L. (Dipsacaceae) caused by infestation of the eriophyid mite Leipothrix dipsacivagus Petanovic et Rector (Acari: Eriophyoidea) under laboratory conditions

The present study describes micro-morphological and histological changes to rosette leaves of the native Eurasian plant species Dipsacus laciniatus (Dipsacaceae) provoked by infestation of the eriophyid mite Leipothrix dipsacivagus Petanovic et Rector. Conspicuous injuries to the leaf tissue were induced by mites feeding on leaves of D. laciniatus rosettes that were propagated from seed under laboratory conditions. Anatomical injuries extended into epidermal cells on the upper and lower leaf surface as well as to the mesophyll layer of infested D. laciniatus leaves. Statistical analysis (by ANOVA and MANOVA) showed significant differences between control and infested plants, particularly in total leaf thickness. The most striking change observed was the decrease in thickness of infested leaves, beginning from the 8th week, associated with the progressive replacement of epidermal cells with an acellular layer. Measures of mite density on test leaves indicated that mites vacated leaves as russeting symptoms intensified. They also appeared to vacate all leaves, whether symptomatic or not, after populations peaked 10–12 weeks after infestation. Comparisons were made between these studies and those on naturally infested, field-collected D. laciniatus plants, as well as with similar studies of other mite-plant interactions.

Morphological Adaptations to Drought and Reproductive Strategy of the Moss Syntrichia caninervis in the Gurbantunggut Desert, China

The biological soil crusts (BSCs) in the Gurbantunggut Desert, the largest fixed and semi-fixed desert in China, feature moss-dominated BSCs, which play an indispensable role in sand fixation. Syntrichia caninervis Mitt. (S. caninervis) serves as one of the most common species in BSCs in the desert. In this study we examined the morphological structure of S. caninervis from leafy gametophyte to protonema using light and scanning electron microscopy (SEM). We also examined the relationships between the morphological structure of S. caninervis and environmental factors. We found that: (1) this moss species is commonly tufted on the sand surface, and its leaves are folded upwards and twisted around the stem under dry conditions; (2) the cells on both upper and lower leaf surfaces have C-shaped dark papillae, which may reflect sunlight to reduce the damage from high temperature; (3) the leaf costa is excurrent, forming an awn with forked teeth; and (4) the protonema cells are small and thickset with thick cell walls and the cytoplasm is highly concentrated with a small vacuole. In addition, we also found that the protonema cells always form pouches on the tip of the mother cells during the process of cell polarization. Our results suggest that S. caninervis has, through its life cycle, several morphological and structural characteristics to adapt to dry environmental conditions. These morphological features of S. caninervis may also be found in other deserts in the world due to the world-wide distribution of the species.