The photosynthetic pigments and photochemical efficiency of photosystem 2 (PS2) were studied in four constitutive species (Achillea millefolium L., Festuca pseudovina Hack. ex Wiesb., Potentilla arenaria Borkh., and Thymus degenianus Lyka) of a semiarid grassland in South-eastern Hungary. Every species displayed typical sun-adapted traits and substantial plasticity in the composition and functioning of the photosynthetic apparatus. The contents of chlorophylls (Chls) and carotenoids (Cars) on a dry matter basis declined from May to July, however, the amount of total Cars on a Chl basis increased. This increase was the largest in Potentilla (48 %) and the smallest in Achillea (14 %). The pool of xanthophylls (VAZ) was between 25 % and 45 % of the total Car content and was larger in July than in May. The content of β-carotene increased by July, but lutein content did not change significantly. The Chl fluorescence ratio Fv/Fm was reduced by 3-10 % at noon, reflecting the down-regulation of PS2 in the period of high irradiance and high temperature. The occurrence of minimal values of ΔF/Fm' showed close correlation to the de-epoxidation rate of violaxanthin. Hence in natural habitats these species developed a considerable capacity to dissipate excess excitation energy in the summer period in their photosynthetic apparatus through the xanthophyll cycle pool and a related photoprotective mechanism, when the photochemical utilization of photon energy was down-regulated. and S. Veres ... [et al.]
The photosynthetic pigments of twigs in five tree and shrub species possessing chlorenchyma under a well developed, stomata-less, and highly photon absorptive periderm were analysed and compared to those of the corresponding canopy leaves. We asked whether the unavoidable shade acclimation of corticular chlorenchyma results in photosynthetic pigment complements typically found in shade leaves. As expected, chlorophyll (Chl) a/b ratios in twigs were consistently low. However, carotenoid (Car) analysis did not confirm the initial hypothesis, since twigs generally contained increased Chl-based pool sizes of the xanthophyll cycle components. The contents of photo-selective neoxanthin and lutein were high as well. Yet, β-carotene content was extraordinarily low. In addition, twigs retained high pre-dawn ratios of the deepoxidized antheraxanthin and zeaxanthin, although environmental conditions were not pre-disposing for such a state. The unexpected Car composition allows the conclusion that other micro-environmental conditions within twigs (hypoxia, increased red to blue photon ratios, and extremely high CO2 concentrations) are more important than shade in shaping the Car profiles. and E. Levizou, Y. Petropoulou, Y. Manetas.
DNA barcoding is a technique of species identification by using
standardized DNA sequence. This technique represents a challenge in the taxonomic approaches avoiding the need of exact knowledge of morphology, particularly when diagnostic morphological features are absent. There has been a considerable debate regarding a locus choice for standard barcode of land plants. Two-locus plastome sequences have been recommended by Plant working group of CBOL for plant barcode: rbcL and matK. The future purposes of this technique suggest using it instead of simple replacement of morphological data to identification of newly found species, recognizing species boundaries and cryptic species, or determination illegally obtained organisms and material even in cases where diagnostic features have been artificially modified.
The following caryophyllidean tapeworms were found in freshwater fishes from Japan (species reported from Japan for the first time marked with an asterisk): family Caryophyllaeidae: Paracaryophyllaeus gotoi (Motomura, 1927) from Misgurnus anguillicaudatus (Cantor); Archigetes sieboldi Leuckart, 1878 from Pseudorasbora parva (Temminck et Schlegel) and Sarcocheilichthys variegatus microoculus Mori (new hosts); family Lytocestidae: *Caryophyllaeides ergensi Scholz, 1990 from Tribolodon hakuensis (Günther), T. ezoe Okada et Ikeda, Hemibarbus barbus (Temminck et Schlegel) and Chaenogobius sp. (new hosts); Khawia japonensis (Yamaguti, 1934) from Cyprinus carpio Linnaeus; K. sinensis Hsü, 1935 from H. barbus (new host) and C. carpio; *K. parva (Zmeev, 1936) from Carassius auratus langsdorfii Valenciennes in Cuvier et Valenciennes and Carassius sp. (new hosts); and *Atractolytocestus sagittatus (Kulakovskaya et Akhmerov, 1962) from C. carpio; family Capingentidae: *Breviscolex orientalis Kulakovskaya, 1962 from H. barbus (new host); and Caryophyllidea gen. sp. (probably Breviscolex orientalis) from C. carpio. The validity of C. ergensi, originally described from Leuciscus leuciscus baicalensis from Mongolia, is confirmed on the basis of an evaluation of extensive material from Japan. Atractolytocestus sagittatus (syn. Markevitschia sagittata) is tentatively considered a valid species, differing from the only congener, A. huronensis Anthony, 1958, in its considerably greater number of testes.
A new coccidian parasite of the genus Caryospora is described from a long nosed vine snake, Ahaetulla nasuta, Lacépède, 1789 from Thailand. Oocysts of Caryospora ahaetullae sp. n. are spherical or slightly subspherical, 24.8 (22.5-26.0) pm in diameter, with a single-layered wall about 0.75 pm thick. A micropyle or oocyst residuum is absent. One, rarely two, polar granules are present, 1.5-2.0 pm. Sporocysts are ellipsoidal, 18.5 x 14.2 (18.0-19.5 x 13.0-15.0) pm with prominent Stieda and substieda bodies. Sporocyst residuum present, consisting of numerous very small granules scattered among 8 sporozoites. Sporo-zoites, with prominent transverse striations anteriorly, are vermiform, 15.0 x 3.8 (13.5-16.5 x 3.5—4.5) pm (in situ), lying lengthwise and parallel within sporocyst. Each sporozoite contains a spherical anterior and spherical to subspherical posterior refractile bodies.
A new coccidian parasite of the genus Caryospora Léger is described from the colubrid snake Boiga dendrophila Boie, 1827 imported from Kalimantan. Oocysts of Caryospora kalimaniunensis sp. n. are spherical, 18.7 (17.0-20.0) pm in diameter, with a bilayered slightly pitted and brownish oocyst wall. A micropyle and oocyst residuum are absent. One globular polar granule is present in 45% of sporulated oocysts. Sporocysts are ovoidal to ellipsoidal, 14.5 (13.0-15.5) x 10.5 (10.0-11.0) pm, with prominent Stieda and substieda bodies. Sporocyst residuum is present as small granules scattered among sporozoites. Sporozoites are elongate, lying lengthwise and parallel within the sporocyst and completely filling the sporocyst. Each sporo-zoite contains a spherical anterior and posterior refractile bodies.
A new coccidian parasite of the genus Caryospora Léger, 1904 is described from the colubrid snake Psammophis schokari (Forskâl, 1775). Oocysts of Caryospora maxima sp. n. are spherical or subspherical, 43.0 (40.0-46.0) X 42.1 (40.0-44.0) pm, with smooth and bilayered oocyst wall ca. 2.0 μιη thick. A micropyle, oocyst residuum and polar granule are absent. Sporocysls are broadly ellipsoidal, 21.3 (21.0-22.0) x 16.3 (16.0-17.0) μιη, with smooth, colourless and unilayered sporocyst wall. Sticda and substieda bodies are present. Sporocyst residuum is present as compact mass of granules lying centrally between sporozoites. Sporozoitcs arc elongate, arranged head to tail within sporocyst. Caryospora maxima represents the first coccidian species described from Psammophis schokari.