Northernmost North American Pinus contorta var. latifolia (lodgepole pine) sociations and vegetation diversity relative to its central range east of the Rocky Mountains

Lodgepole pine (Pinus contorta var. latifolia) stands were sampled in central Yukon, Canada (61.5–64°N latitude), which represented the northernmost 9% of the tree's North American range. Within this area, lodgepole pine occupied only ? 2% of the landscape. This study determined: 1) what forest sociations occurred (i.e. structural dominance‐types); 2) how plant growth form composition and richness differed from the central portion of the species’ geographical range; and 3) if stands were biased towards occurring on more thermally favorable south‐facing slopes. Five lodgepole pine sociations were recognized among 100 relevés: Rhododendron groenlandicum (Labrador tea); Cladonia arbuscula (green reindeer lichen); Calamagrostis purpurascens (purple reedgrass); Hylocomium splendens (stairstep moss) and Alnus viridis (green alder, n = 4 relevés). Rhododendron stands were proportionally more common on low gradient sites and had more total plant cover than the other sociations. Cladonia and Calamagrostis stands were typically associated with dry coarse‐textured soils and warm dry sites, respectively; whereas the composition of the Hylocomium sociation reflected the detrimental influences of atypically dense forest canopies on understory vascular plants. Only the Calamagrostis sociation was unique to the study region. Species richness among common northern lodgepole pine sociations averaged 16–19 taxa per relevé (p > 0.05). Northern compared to central range (n = 1394) relevés were compositionally different based on little overlap of their datasets in the ordination space. Northern vegetation had less (p < 0.001) total plant (129% vs 184%), deciduous shrub (9% vs 26%), broad‐leaved herb (5% vs 25%), and bryophyte (27% vs 54%) cover; had greater macro‐lichen cover (13% vs 5%) and lower floristic richness (11 vs 24 taxa) and was less than half as phytosociological diverse. Lodgepole pine stands in the northernmost portion of their range were not biased towards occurring on south‐facing slopes, which suggested an ecological potential for range expansion.     

Defence syndromes in lodgepole – whitebark pine ecosystems relate to degree of historical exposure to mountain pine beetles

Warming climate is allowing tree‐killing bark beetles to expand their ranges and access naïve and semi‐naïve conifers. Conifers respond to attack using complex mixtures of chemical defences that can impede beetle success, but beetles exploit some compounds for host location and communication. Outcomes of changing relationships will depend on concentrations and compositions of multiple host compounds, which are largely unknown. We analysed constitutive and induced chemistries of Dendroctonus ponderosae's primary historical host, Pinus contorta, and Pinus albicaulis, a high‐elevation species whose encounters with this beetle are transitioning from intermittent to continuous. We quantified multiple classes of terpenes, phenolics, carbohydrates and minerals. Pinus contorta had higher constitutive allocation to, and generally stronger inducibility of, compounds that resist these beetle–fungal complexes. Pinus albicaulis contained higher proportions of specific monoterpenes that enhance pheromone communication, and lower induction of pheromone inhibitors. Induced P. contorta increased insecticidal and fungicidal compounds simultaneously, whereas P. albicaulis responses against these agents were inverse. Induced terpene accumulation was accompanied by decreased non‐structural carbohydrates, primarily sugars, in P. contorta, but not P. albicaulis, which contained primarily starches. These results show some host species with continuous exposure to bark beetles have more thoroughly integrated defence syndromes than less‐continuously exposed host species.     

Novel terpenoids from Calocedrus macrolepis var. formosana

Calocetriol ( 1 ), diacetylcalocediol ( 2 ), and ferrugimenthenol ( 3 ) were isolated from the bark of Calocedrus macrolepis var. formosana. Among them, 1 and 2 are secoabietane‐type diterpenoids, and 3 , with a novel C₂₀ C₁₀ skeleton, is classified as a meroterpenoid. The structures of 1 – 3 were elucidated by spectroscopic analyses, and their biological activities were also evaluated. Compound 3 exhibited significant cytotoxic activity against human oral epidermoid carcinoma KB cells with an IC₅₀ value of 9.0±0.1 μM .     

Cryptococcus antarcticus var. circumpolaris var. nov., a basidiomycetous yeast from Antarctica

Cryptococcus antarcticus Vishniac & Kurtzman var. circumpolaris Vishniac and Onofri var. nov. (Filobasidiales, Tremellomycetidae, Hymenomycetes), an anamorphic yeast with ca. 73% nDNA relatedness to Cryptococcus antarcticus var.antarcticus, differs in failure to assimilate raffinose, a lower maximum temperature for growth, fatty acid profile, and in a single nucleotide change in the D2 region of LSU rDNA. This revised version was published online in June 2006 with corrections to the Cover Date.     

Tremacron aurantiacum var. weiningense (Gesneriaceae) var. nov. from Guizhou,China

Tremacron aurantiacum var. weiningense (Gesneriaceaea), a new variety of Tremacron aurantiacum found in northwest Guizhou, China, is described and illustrated. This new variety differs from T. aurantiacum K. Y. Pan var. aurantiacum in the following respects: it has appressed pubescence and tomentum on the lower surface of its leaves, inflorescence is 4–8‐flowered, 5–10 cymes, peduncles and pedicels are covered with glandular pubescence, the corolla is thin with tube‐like upper lips indistinct and cut‐like, the stigma is 1, capitate.     

Oscillatoria agardhii var. suspensa nov. var.

Zusammenfassung Oscillatoria agardhii var. suspensa n. var. ist ein Süßwasser-Planktont, der O. agardhii nahe steht, sich aber durch geringere Abmessungen und den Bau der Trichom-Enden unterscheidet. Sie wurde durch Waschen von anderen Organismen befreit, was bisher noch bei keiner Cyanophycee gelungen war.Die Art lebt im Wasser schwebend. Nur in alten Kulturen sammelt sie sich an der Oberfläche an. O. agardhii var. suspensa ist streng photo-autotroph und macht von organischen Nährstoffen keinen Gebrauch. Sie ist sogar sehr empfindlich gegen manche von ihnen, besonders gegen Glucose (aber nicht gegen andere Zucker), die schon in geringen Konzentrationen die Vermehrung unterdrückt.Die weißlich-grüne Farbe der Art wird durch die Pseudovacuolen bewirkt; der Chlorophyllgehalt ist aber nicht geringer als der von anderen Cyanophyceen, die tief blaugrün aussehen.

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Summary Oscillatoria agardhii var. suspensa n. var. is a freshwater planktont allied to O. agardhii but differing in smaller dimensions and the shape of the trichome-ends. It was freed from other organisms by the washing procedure, a technique that had not yet been successful in any member of the Cyanophyceae.The organism lives suspended in the water except in old cultures when it tends to accumulate near the surface. O. agardhii var. suspensa is strictly photo-autotrophic not utilizing any organic nutrients and even to some of them very sensitive, particularly to glucose (though not to other sugars) which prevents growth at minute concentrations.The whitish green hue of the species is due to pseudovacuoles while the content of chlorophyll is not lower than that of Cyanophycean species appearing deep blue-green to the eye.

     

A method for studying dead bole dynamics in Pinus contorta var. latifolia - Picea engelmannii forests

Rates of decomposition were determined for the boles of Pinus contorta var. latifolia Engelm. and Picea engelmannii Parry ex. Engelm. in five lower subalpine forest stands in the Southern Canadian Rocky Mountains. Stands ranged in age from 58 to 222 yr since last fire. The date of death of standing dead and fallen boles was determined by cross-dating their ring-width patterns to stand master ring- width chronologies. Boles could be dated which had been dead for up to 35 years in a 58-yr old stand and 100 yr in a 222-yr old stand. An empirical relationship between mass density and diameter of live trees was used to predict the mass density at death for trees already dead. The falling rate of dead standing boles was estimated from the dead bole's time of death and whether it was standing or on the ground at the time of observation. The falling rates for both Pinus contorta and Picea engelmannii ranged from 0.020 to 0.064/yr falling with most stands in the 0.050 range. No effect of size was found on the falling rate probably as a result of the small size of the boles (< 20 cm). Because of their dry condition standing dead boles do not decompose. An equation was developed which estimates the time a dead bole has been on the ground, given that it would have stood for some time before falling over and been subject to little decomposition during this time. Decomposition rates, using a negative exponential model, gave only marginally better r² than linear models. Pinus contorta had exponential decay rates from 0.0299 and 0.0171 mass density loss/yr for the most recent 15 and 25 yr in stands 58 yr old, to 0.0045 and 0.0035 mass loss/yr for the most recent 65 and 80 yr in stands 215 and 222 yr old. Picea engelmannii had exponential decay rates of 0.0054 and 0.0025 mass loss/yr for the most recent 20 and 65 yr in stands 99 and 215 yr old.     

Development of Pseudocercosporella herpotrichoides (Fron) Deighton var. herpotrichoides and var. acuformis on Wheat Plants Measured by ELISA

Using the ELISA method, the development of Pseudocercosporella herpotrtchoides var. herpotrichoides and var. acuformis in a susceptible cultivar of winter wheat was compared under controlled and held conditions. In the greenhouse, var. acufornis grew less vigorously, was slower in penetrating the coleoptile and the successive leaf sheaths and in colonizing the stem tissue than var. herpotrichoides. In the field, these differences were confirmed on the last leaf sheaths and the stem. At ripening stage, however, identical ELISA values were measured for both varieties. Moreover, a significant variation was observed between the individual isolates of each variety. Comparison of the effect of both varieties of P. herpotrichoides on 20 wheat cultivars characterized by different resistance levels showed significant interactions. The cultivars carrying the Pch-1 gene always remained the less diseased genotypes. In general, var. acuformis developed less antigen in the cultivars than var. herpotrichoides. It is concluded, that in tests for resistance to P. herpotrichoides mixtures of many highly pathogenic isolates of both fungus varieties should be used. Less complex mixtures or single isolates may result in wrong estimates of resistance.     

Chemical Diversity of Volatiles of Teucrium orientale L. var. orientale,var. puberulens,and var. glabrescens Determined by Simultaneous GC‐FID and GC/MS Techniques

In the present work, three varieties of Teucrium orientale, var. orientale, var. puberulens, and var. glabrescens, were collected and investigated for chemical composition of the oils. Subsequent gas chromatography (GC‐FID) and gas chromatography coupled to mass spectrometry (GC/MS) revealed high abundance of sesquiterpenes in the essential oils analyzed. All the oils contained β‐caryophyllene (22.6, 8.5, and 6.3%, resp.) and hexadecanoic acid (7.9, 12.8, and 13.1%). Germacrene D (24.6 and 33.4%) and bicyclogermacrene (6.7 and 8.5%) were found to be the main constituents of var. orientale and var. puberulens, respectively. The high percentages of β‐cubebene (26.9%), α‐cubebene (9.0%), and α‐copaene (7.2%) established the diversity of var. glabrescens. The qualitative difference between the essential oils allowed the differentiation between the varieties in agreement with the morphological observations described in Flora of Turkey for each variety studied. In addition, a cluster analysis of twelve Teucrium taxa based on the essential‐oil composition has been carried out. Hovewer, the analysis did not clearly reflect the infrageneric classification of the genus, it largely confirmed the relationships between the infraspecific taxa of Teucrium orientale and T. chamaedrys.     

Palynological study of Cupressus sempervirens L. var. pyramidalis and var. horizontalis

ABSTRACT

Cupressus sempervirens L. var. pyramidalis and C. sempervirens var. horizontalis were examined for their pollen morphometry and ultrastructure to verify whether, in addition to phenotype, pollen could also show characteristics useful to discriminate the two infraspecific taxa. C. sempervirens var. pyramidalis compared to C. sempervirens var. horizontalis has mainly larger, subcircular pollen with a higher percentage of apolar and germinating grains, and a wall with thicker intine; the cytoplasm has a greater number of callose-containing vesicles. C. sempervirens var. horizontalis has pollen distributed in five classes of shape. In addition it is smaller and shows a higher percentage of ruptured grains, and a lower percentage of germination in vitro. The cytoplasm contains vesicles rich in callose and also a higher amount of osmophilic bodies. Pollen grains in both varietas contain only one cell at dispersal. The reported differences in pollen morphometry, structure and biology, together with the phenotypic characteristics of the tree, support the validity of two infraspecific taxa.     

Bioactivity-guided isolation of antioxidant triterpenoids from Betula platyphylla var. japonica bark

The bark of Betula platyphylla var. japonica (Betulaceae) has been used to treat pneumonia, choloplania, nephritis, and chronic bronchitis. This study aimed to investigate the bioactive chemical constituents of the bark of B. platyphylla var. japonica. A bioassay-guided fractionation and chemical investigation of the bark of B. platyphylla var. japonica resulted in the isolation and identification of a new lupane-type triterpene, 27-hydroxybetunolic acid (1), along with 18 known triterpenoids (2–19). The structure of the new compound (1) was elucidated on the basis of 1D and 2D NMR spectroscopic data analysis as well as HR-ESIMS. Among the known compounds, chilianthin B (17), chilianthin C (18), and chilianthin A (19) were triterpene-lignan esters, which are rarely found in nature. Compounds 4, 6, 7, 17, 18, and 19 showed significant antioxidant activities with IC₅₀ values in the range 4.48–43.02 μM in a DPPH radical-scavenging assay. However, no compound showed significant inhibition of acetylcholine esterase (AChE). Unfortunately, the new compound (1) exhibited no significance in both biological activities. This study strongly suggests that B. platyphylla var. japonica bark is a potential source of natural antioxidants for use in pharmaceuticals and functional foods.     

Inter-simple sequence repeat (ISSR) diversity within Monarda fistulosa var. brevis (Lamiaceae) and divergence between var. brevis and var. fistulosa in West Virginia

Inter-simple sequence repeat (ISSR) banding patterns were used to examine genetic diversity within and among populations ofMonarda fistulosa var.brevis, a rare taxon restricted to several populations in limestone glades and barrens in eastern West Virginia and Virginia. More than 34% of the total ISSR diversity in var.brevis occurred among populations, which is high when compared to the few other rare species that have been examined for ISSR variation. Prior studies demonstrated that var.brevis is morphologically distinct from the more widespread var.fistulosa, and that the differences are maintained when the two varieties are grown together in a uniform environment. The present study utilizing ISSR markers indicated that the two varieties are distinct, though quite similar genetically, and this is concordant with prior investigations documenting their morphological and habitat differences. However, the ISSR results suggest that the two varieties have diverged relatively recently and/or there is a low level of gene flow between them.     

Trichophyton rubrum (Castellani) var. flava,var. nova a yellow pigment forming Trichophyton rubrum

Summary and Conclusions A hitherto unknown variant ofT. rubrum var.flava is described which besides its yellow pigment has the following characteristics different fromT. rubrum (Castellani). A much slower growth and a smaller diameter of the giant culture and an appreciable difference in the light absorption curve of the extracted pigment.     

Mitochondrial DNA analysis of Exophiala jeanselmei var. lecanii-corni and Exophiala castellanii

A Japanese clinical isolate (KU-A-0094) which was identified by de Hoog et al. as Exophiala jeanselmei var. lecanii-corni with difficulty, was compared with 5 strains including the type cultures of E. jeanselmei var. lecanii-corni, var. jeanselmei and E. castellanii using RFLP (restriction fragment length polymorphism) patterns of mtDNA (mitochondrial DNA). RFLP patterns of KUA-0094 were identical with those of E. jeanselmei var. lecanii-corni and different from those of E. castellanii with restriction enzymes of HaeIII, MspI and hindIII. Therefore, de Hoog et al.'s identification of KU-A-0094 was confirmed. Additionally, mtDNA-RFLP patterns of E. jeanselmei var. lecanii-corni and E. jeanselmei var. jeanselmei were also different from each other. Consequently E. jeanselmei var. lecanii-corni seem to be a species in its own right rather than a variant of E. jeanselmei. This revised version was published online in June 2006 with corrections to the Cover Date.     

Two serratane triterpenes from the stem bark of Picea jezoensis var. hondoensis

Two serratane triterpenoids were isolated from the stem bark of Picea jezoenis var. hondoensis, together with two known compounds, 3β-methoxyserrat-14-en-21-one and 3β-methoxyserrat-14-en-21α-ol. The serratane triterpenoids were characterized as 14β,15β-epoxy-3α-methoxyserratan-21β-ol and 3α-methoxy-21β-hydroxyserrat-14-en-16-one, on the basis of chemical and spectroscopic evidence.     

Space allocation in Melanophila knoteki knoteki (Reitt.) var. hellenica (Obenberger) (Col., Buprestidae) in the attack of Greek fir [Abies cephalonica Loud. var. graeca (Fraas) Liu]: a pattern to process approach

The phloeo‐cambiophagous buprestid Melanophila knoteki knoteki (Reitt.) var. hellenica (Obenberger.) is not a primary factor of fir decline problem although the beetle substantially contributes to Greek fir Abies cephalonica Loud. var. graeca (Fraas) Liu mortality. By using mapping depiction of the exit holes of the insect on a set of fir trees located on a line transect in a randomized point‐centred quarter scheme and employing pattern analysis techniques we were able to reveal various scales of the infestation pattern. Four scales were recognized, two of them corresponding to the pattern of microsite selection on the bark of a fir tree. While the dispersed exit holes exhibited a statistically significant random dispersion on the bark, within each aggregation the pattern was uniform. The area of compartments created by Dirichlet partition approximated very well the sizes of the actual larval galleries. The Dirichlet tessellation of the bark space and the analysis of the parameter of the resulting partitions showed the predominance of the hexagonal conformation of the larval spaces when space was limited. When some exit holes were positioned close together it was found that they were directed away from each other so the resulting galleries were well separated. Several hypotheses are presented as to the mechanisms underpinning the observed patterns. The allocation of space is in accordance with the widely accepted ‘central place theory’ of W. Christaller, a general theory of pattern generated in the geographical dispersion of human settlements. The revealed pattern was also in accordance with the predictions of the theory of ‘central place foraging’ of R. H. MacArthur and the theory of ‘resource concentration hypothesis’ of R. Root.     

Correction of crown disorders ofPinus caribaea var.hondurensis by application of zinc

Summary Trees of a highland provenance ofPinus caribaea var.hondurensis Barr. and Golf. in an unhealthy stand on Melville Is., Australia displaying symptoms of needleless shoots, short needles, premature needle fall, resin exudation from the stem, fasciation of the stem tip tip dieback and multiple leadering were markedly improved by the application of Zn. Other plantings of highland provenances ofP. caribaea var.hondurensis in the lowland tropics with similar disorders may benefit from Zn application.     

Allometry of Prosopis glandulosa var. torreyana along a topographic gradient in the Chihuahuan desert

Abstract. The allometric relationships of trees in temperate and tropical forests are relatively well known, but not those of woody shrubs or transitional (shrub/tree) life forms. We explored the transition of Prosopis glandulosa var. torreyana from tree to shrub along a semi‐arid topographic sequence comprising of six landforms (hillslope, footslope, upper and lower bajada, playa and dune) with varying soil texture and water availability. In each landform, we measured P. glandulosa shoot pre‐dawn water potentials (Ψ) in one ‘dry’ and one ‘wet’ year. We also measured plant height, widest basal stem diameter, crown area and number of basal branches. Total basal stem area was calculated. We used simple (Model II linear regression) and expanded (incorporating an asymptote to height or crown area) allometry models to compare height with widest basal stem diameter and crown area with total basal stem area. There were significant correlations between maximum plant size and inter‐year Ψ means suggesting that soil water availability decreased down the topographical sequence. The height asymptote was statistically significant in all landforms and lower toward finer‐textured soils. On the other hand, crown area was a linear function of total basal stem area and was also site specific. Our results suggest that more basal branches are produced as plant height decreases in more stressful environments, effectively increasing crown area with a minimum investment in supporting tissues. The polymorphic characteristics of Prosopis may partly explain their occurrence in many arid and semi‐arid environments.     

The Influence of Glycoalkaloids and Impact Damage on Resistance to Fusarium solani var. coeruleum and Phoma exigua var. foveata in Potato Tubers

Potato glycoalkaloids were determined in tubers of a wide range of genotypes in order to study their influence on resistance to storage rots caused by Fusarium solani var. coeruleum and Phoma exigua var. foveata. No relationships were found. This indicates that breeders selection for low glycoalkaloid potato clones is not in conflict with the demands for high levels of resistance to these pathogens. It was also observed that genotypes susceptible to skin-breaking types of, damage were more easily infected than genotypes susceptible to other types of damage.