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121.
A comprehensive study of stem, leaf and petiole anatomy of 10 species of Strobilanthes from northern Western Ghats of India was carried out to identify characteristics which would enable species identification when flowering material is unavailable. In Strobilanthes, some species bloom annually, others are plietesials, i.e. they grow without blooming for several years and then produce huge quantities of flowers, release seeds and die. Therefore, alternative methods, such as anatomical characters, are essential to distinguish Strobilanthes species in their vegetative stage. We collected ten species of Strobilanthes for anatomical characterization. Under the bright‐field microscope, stem cross‐sections of different species were found to be undulate, quadrangular, quadrangular‐winged or terete. Study of the stem revealed a distinct outer and inner cortex, the distribution of cystoliths (CaCO3 crystals), raphides (CaC2H2O5 crystals) and sclereids which varied from species to species. Study of leaf anatomy showed structural variation and vascular bundle shapes that differed between the species. Leaf epidermal characters under light and scanning electron microscopy exhibited variation in characters such as stomatal index, stomatal length and width, stomatal type and presence of glandular and non‐glandular trichomes. The petiole anatomy was species‐specific, especially with respect to vascular bundle structure and the distribution of structures such as sclereids, cystoliths, sphaeraphides and tannin cells varied. Hence, unique anatomical features of the stem, leaf and petiole could be used as taxonomic characters to identify Strobilanthes species in a vegetative state.  相似文献   
122.
Plants have evolved a multitude of adaptations to survive extreme conditions. Succulent plants have the capacity to tolerate periodically dry environments, due to their ability to retain water in a specialized tissue, termed hydrenchyma. Cell wall polysaccharides are important components of water storage in hydrenchyma cells. However, the role of the cell wall and its polysaccharide composition in relation to drought resistance of succulent plants are unknown. We investigate the drought response of leaf‐succulent Aloe (Asphodelaceae) species using a combination of histological microscopy, quantification of water content, and comprehensive microarray polymer profiling. We observed a previously unreported mode of polysaccharide and cell wall structural dynamics triggered by water shortage. Microscopical analysis of the hydrenchyma cell walls revealed highly regular folding patterns indicative of predetermined cell wall mechanics in the remobilization of stored water and the possible role of homogalacturonan in this process. The in situ distribution of mannans in distinct intracellular compartments during drought, for storage, and apparent upregulation of pectins, imparting flexibility to the cell wall, facilitate elaborate cell wall folding during drought stress. We conclude that cell wall polysaccharide composition plays an important role in water storage and drought response in Aloe.  相似文献   
123.
以‘窄叶藤本月季花’( Rosa chinensis ‘Zhaiye Tengben Yuejihua’)ב月月粉’( R. chinensis ‘Old Blush’)杂交群体为材料, 分析其花瓣数量的分离特点, 对单瓣花与重瓣花的花芽分化过程进行观察, 并对花瓣、雄蕊及瓣化雄蕊进行表皮细胞超微结构的观察.结果显示...  相似文献   
124.
Whole-animal anatomy is used in a cladistic analysis of five genera of brackish-water hydrobiids living in the western Atlantic. Antillobia margalefi gen. & sp. nov. (Hydrobiidae: Littoridininae) is described based on specimens from Lago Enriquillo, an inland saline lake in the Dominican Republic. The topology ( Hydrobia ( Spurwinkia ( Heleobia ( Heleobops ( Antillobia ))))) is considerably better than any alternative. Among 27 characters and a total of 39 character states used in the analysis, only two convergences are detected, and these involve the genitalia. Detailed anatomical data are shown to be necessary to assess relationships in the presence of constraints on morphological evolution imposed by a very small size.  相似文献   
125.
We describe the anatomy of the nerves that project from the central nervous system (CNS) to the pro‐ and mesothoracic segments and the cephalopharyngeal skeleton (CPS) for third instar Calliphora larvae. Due to the complex branching pattern we introduce a nomenclature that labels side branches of first and second order. Two fine nerves that were not yet described are briefly introduced. One paired nerve projects to the ventral arms (VAs) of the CPS. The second, an unpaired nerve, projects to the ventral surface of the cibarial part of the esophagus (ES). Both nerves were tentatively labeled after the structures they innervate. The antennal nerve (AN) innervates the olfactory dorsal organ (DO). It contains motor pathways that project through the frontal connectives (FC) to the frontal nerve (FN) and innervate the cibarial dilator muscles (CDM) which mediate food ingestion. The maxillary nerve (MN) innervates the sensory terminal organ (TO), ventral organ (VO), and labial organ (LO) and comprises the motor pathways to the mouth hook (MH) elevator, MH depressor, and the labial retractor (LR) which opens the mouth cavity. An anastomosis of unknown function exists between the AN and MN. The prothoracic accessory nerve (PaN) innervates a dorsal protractor muscle of the CPS and sends side branches to the aorta and the bolwig organ (BO) (stemmata). In its further course, this nerve merges with the prothoracic nerve (PN). The architecture of the PN is extremely complex. It innervates a set of accessory pharyngeal muscles attached to the CPS and the body wall musculature of the prothorax. Several anastomoses exist between side branches of this nerve which were shown to contain motor pathways. The mesothoracic nerve (MeN) innervates a MH accessor and the longitudinal and transversal body wall muscles of the second segment. J. Morphol. 271:969–979, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
126.
Recent studies have described the giant tadpole, delayed metamorphic transformations, and absence of postmetamorphic growth of the skeleton of Pseudis Platensis. These features address questions about derived patterns of life cycles and the role of the heterochrony during the metamorphosis in anurans. Using anatomical methods, we provide new data on the development of reproductive, digestive and integument systems, and age inference obtained from ontogenetic series of Pseudis platensis. Our results indicate that at the end of metamorphosis, the adult skin is completely differentiated, including the calcified dermal layer; the testis has seminiferous tubules with spermatogonia, spermatocytes, and spermatids; ovarian sacs present previtellogenic ova; and the adult digestive tract is fully formed. The froglets differ from adults only in being unable to reproduce. The entire life cycle of P. platensis can occur in 4 years. In the first year, larval development, growth to adult size, and gonad differentiation are completed. Long larval development rather than size of the tadpoles seems to be involved in the absence of juvenile stages. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.  相似文献   
127.
Summary A five and a half weeks old female Kestrel exhibiting osteopathy of the pectoral and pelvic limbs, including symmetrical hyperdactyly, was investigated in order to clarify the pattern of the involved anatomical alterations and the possible causes of this developmental malformation. In the pectoral limb it consisted of a triplication of the alular digit, in the pelvic limb of a duplication of digit I. The live young Kestrel was observed for a period of two weeks to ascertain that it was unable to fly or procure prey on its own. After its death radiographs were taken and, apart from an eidonomic inspection including the wing claws, a detailed macroscopic dissection of the musculature of the pectoral and pelvic limbs was carried out using the in-water-method. Consecutive dissection steps were documented by a series of photographic slides. The relevant musculature, particularly that of the supernumerary digits, was recorded in proportional drawings. Subsequent to maceration of the limbs the isolated bones were reassembled according to the radiographs and also documented by means of photographs and drawings. This anatomical approach produced a reliable reconstruction of the skeletomuscular apparatus of the hyperdactylous limb parts. The eidonomic inspection revealed that at least young Kestrels may have two (alular and major digit) or even three wing claws per side. The proximal skeletal elements of both pectoral and pelvic limb were more sturdily built than in a typical Kestrel of comparable age. The proximal elements of the pelvic limb, the tarsometatarsus in particular, were shorter than in a typical Kestrel. In addition, the long axis of the tarsometatarsus was laterally bent in the transverse plane so that its proximal articular surfaces were medially inclined. Duplication of the cutaneous and osseous elements in the foot was accompanied by a duplication of some of the muscular and/or tendinous elements supplying digit I proper and the accessory digit I'. There were left-to-right asymmetries of the pedal musculature concerned. In contrast, the two accessory alular digits of each wing were almost completely devoid of musculature. Apart from atypical points of origin or insertion of the remaining distal musculture, left-to-right asymmetries and the two accessory alulae per wing, presumably, affected aerodynamic properties and resulted in flightlessness.A juvenile Kestrel of similar age and without hyperdactyly was dissected for comparison. In addition, the external appearance of the carpometacarpal region of two female Silkies, an obligatory pentadactylous breed of domestic fowl, was inspected and the skeletal parts of their pectoral and pelvic limbs compared with those of the hyperdactylous Kestrel. Our results and a literature review suggest that the symmetrical hyperdactyly in the Kestrel bears striking similarities to the hereditary hyperdactyly observed in certain breeds of domestic fowl. In addition, there is a striking resemblance between the hyperdactyly of the young Kestrel and certain forms of hyperdactyly induced by molecular genetical experiments of other authors on chicks. Comparison with these results taken from the literature suggest that the symmetrical hyperdactyly in the young Kestrel, including the alterations of the proximal skeletal elements, is caused by an unusually early expression of the Hoxd-11 gene group during embryological development. Most likely, this gene group is situated on the 2nd chromosome in birds just as it is in mammals.
Osteopathie der Vorder - und Hinterextremitäten, verbunden mit einer symmetrischen Hyperdactylie bei einem jungen Turmfalken (Falco tinnunculus)
Zusammenfassung Ein fünfeinhalb Wochen alter weiblicher Turmfalke mit einer Osteopathie der Vorder- und Hinterextremitäten, verbunden mit einer symmetrischen Hyperdactylie, wurde untersucht, um das Muster der beteiligten anatomischen Veränderungen und die möglichen Ursachen dieser Mißbildung zu erkennen. An der Vorderextremität bestand sie aus einer Verdreifachung des Alula-Fingers, an der Hinterextremität aus einer Verdoppelung der Zehe I. Die Beobachtung des lebenden jungen Turmfalken während eines Zeitraumes von zwei Wochen ergab, dass er flugunfähig war und keine Beute schlagen konnte.Nach seinem Tod und einer Inspektion der Eidonomie, einschließlich der Flügelkrallen, wurden Röntgenaufnahmen angefertigt. Danach folgte eine detaillierte makroskopische Präparation der Flügel- und Beinmuskulatur unter Verwendung der In-Wasser-Methode. Die einzelnen Präparationsschritte wurden anhand von Dia-Serien dokumentiert. Die relevante Muskulatur, insbesondere die der überzähligen Digiti, wurde in proportionsgetreuen Zeichnungen festgehalten. Nach Mazeration der Extremitäten wurden die Einzelknochen, entsprechend den Röntgenbildern, wieder zusammengesetzt und ebenfalls mit Fotografien und Zeichnungen dokumentiert. Dieser anatomische Ansatz lieferte eine zuverlässige Rekonstruktion des Skelett-Muskel-Apparates der hyperdactylen Extremitätenanteile.Die eidonomische Inspektion ergab, dass zumindest junge Turmfalken zwei (Digitus alularis und majoris) oder sogar drei Flügelkrallen haben können. Die proximalen Skelettelemente der Vorder- und Hinterextremität waren deutlich robuster gebaut als bei einem typischen Turmfalken vergleichbaren Alters. Die proximalen Elemente der Hinterextremität, insbesondere der Tarsometatarsus, waren kürzer als bei einem typischen Turmfalken. Darüberhinaus war die Längsachse des Tarsometatarsus in der Transversalebene laterad gekrümmt, so dass sich seine proximalen Gelenkflächen schräg mediad richteten. Entsprechend der kutanen und knöchernen Doppelbildungen des Fußes waren auch einige der Muskeln und Sehnen doppelt vorhanden, welche die eigentliche erste Zehe und die akzessorische erste Zehe versorgten. Es traten Rechts-/Links-Asymmetrien der betreffenden Muskulatur auf. Im Gegensatz dazu waren die beiden akzessorischen Alula-Finger jedes Flügels fast vollständig ohne Muskulatur. Abgesehen von atypischen Ursprungs- und Insertionspunkten der verbleibenden distalen Muskulatur, beeinträchtigten Rechts-/Links-Asymmetrien und die beiden akzessorischen Alulae pro Flügel vermutlich die aerodynamischen Eigenschaften und führten zur Flugunfähigkeit.Ein junger Turmfalke ähnlichen Alters ohne Hyperdactylie wurde zum Vergleich präpariert. Zusätzlich wurde die äußere Erscheinung der Carpometacarpal-Region zweier Seidenhühner, einer obligatorisch pentadactylen Hühnerrasse, inspiziert und die Skelettelemente ihrer Vorder- und Hinterextremitäten mit denen des hyperdactylen Turmfalken verglichen. Unsere Ergebnisse und ein Überblick der Literatur lassen auffallende Übereinstimmungen zwischen der symmetrischen Hyperdactylie des jungen Turmfalken und der erblichen Hyperdactylie bestimmter Hühnerrassen erkennen. Darüberhinaus besteht eine auffallende übereinstimmung zwischen der Hyperdactylie des jungen Turmfalken und bestimmten Formen der Hyperdactylie, welche von anderen Autoren durch molekulargenetische Experimente an Hühnerküken induziert wurden. Ein Vergleich mit diesen Ergebnissen aus der Literatur legt nahe, dass die symmetrische Hyperdactylie des jungen Turmfalken, einschließlich der Veränderungen der proximalen Skelettelemente, durch eine ungewöhnlich frühe Expression der Hoxd-11 Gengruppe im Laufe der Embryonalentwicklung verursacht wurde. Sehr wahrscheinlich ist diese Gengruppe bei Vögeln auf dem zweiten Chromosom lokalisiert — ebenso wie bei Säugetieren.
  相似文献   
128.
A new species of Bucklandia is described based on a permineralized fossil trunk that was obtained from sediments of Upper Cretaceous age from Hokkaido, Japan. The quality of preservation is exquisite, and anatomical and morphological features are preserved at the cellular level. The specimen is clearly bennettitalean because of the cycadeoidean-type arrangement of vascular bundles in the petiole. However, this specimen is unique among previously described progymnosperms and gymnosperms in possessing a unilacunar five-trace type of nodal structure. The fossil thus contributes to a more complete understanding of the variation of nodal structure in bennettitalean trunks.  相似文献   
129.
The amphibious leafless sedge Eleocharis retroflexa ssp. chaetaria expresses C4-like biochemical characteristics in both the terrestrial and submerged forms. Culms of the terrestrial form have Kranz anatomy, whereas those of the submerged form have Kranz-like anatomy combined with anatomical features of aquatic plant leaves. We examined the immunolocalization of C3 and C4 enzymes in culms of the two forms. In both forms, phosphoenolpyruvate carboxylase; pyruvate, Pi dikinase; and NAD-malic enzyme were compartmentalized between the mesophyll (M) and Kranz cells, but their levels were somewhat reduced in the submerged form. In the terrestrial form, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) occurred mainly in the Kranz cells, and weakly in the M chloroplasts. In the submerged form, the rubisco occurred at higher levels in the M cells than in the terrestrial form. In both forms, the C4 pattern of enzyme expression was clearer in the M cells adjacent to Kranz cells than in distant M cells. During the transition from terrestrial to submerged conditions, the enzyme expression pattern changed in submerged mature culms that had been formed in air before submergence, and matched that in culms newly developed underwater. It seems that effects of both environmental and developmental factors overlap in the C4 pattern expression in this plant.  相似文献   
130.
The capture of patchily distributed nutrients by tree roots has received extensive research, but the fate of those nutrients has not. We performed experiments to determine if nutrient transport within tree species is preferentially transported from specific roots to specific branches. Saplings of five species with contrasting growth requirements were examined: two Betula species (B. papyrifera and B. lenta), Populus tremuloides, and two Acer species (A. saccharum and A. rubrum). To quantify patterns of long-distance transport, we examined the accumulation of safranin-O dye and 15N in branches when these tracers were applied to isolated lateral roots (dye and 15N) and to the main root system (15N). Because transport of nutrients between sectors requires flow through intervessel pit pairs of adjacent xylem vessel elements, we quantified the area of intervessel pits, the number of pits per unit vessel wall area, and the % vessel wall area as pits in Acer and Betula. We found that the two Betula species were integrated (tracers applied to isolated roots were likely to accumulate in all branches), while P. tremuloides and the two Acer species were sectorial (tracer accumulation was more concentrated in particular branches). Betula had the largest number of intervessel pits per unit vessel wall area and the largest percentage of vessel wall area as pits. The high density of bordered pits may explain the ease of tracer movement throughout the two Betula species. Greater integration may allow certain trees (e.g., Betula) to exploit nutritionally patchy environments such as rocky soils, and may alter plant-herbivore interactions.  相似文献   
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