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821.
Ismael Sánchez-Jiménez Jaume Pellicer Oriane Hidalgo Sònia Garcia Teresa Garnatje Joan Vallès 《Folia Geobotanica》2009,44(3):307-322
Chromosome counts are reported for 15 species of the family Asteraceae from Inner Mongolia (People’s Republic of China). This study includes representatives of the tribes Anthemideae (Artemisia, Chrysanthemum, Filifolium, Hippolytia and Neopallasia), Astereae (Heteropappus) and Cardueae (Echinops and Olgaea). The significance of the chromosome counts is discussed for each species. Within the Anthemideae, chromosome counts for Hippolytia alashanensis (2n?=?36) and the tetraploid level of Artemisia eriopoda (2n?=?36) are reported for the first time. The chromosome number of Heteropappus altaicus (Astereae) agrees with previous reports of one (4x) of the two ploidy levels reported for this taxon. As a complement to the karyological data, genome size of the Cardueae representatives was assessed using flow cytometry. Within this tribe, Echinops gmelini (2n?=?26) and its sister taxon E. acantholepis (2n?=?14) show strongly divergent karyological patterns of difficult interpretation, whereas the count of E. przewalskyi (2n?=?32), assigned here for the first time, coincides with those of its close relatives. In Olgaea tangutica, the chromosome count (2n?=?24) and genome size (2C?=?3.01 pg) given here are the first reports for both the species and the genus. 相似文献
822.
Here we improve the mathematical arguments of Baixeries et al (BioSystems 107(3) (2012) 167–173). The corrections do not alter the conclusion that the random breakage model yields an insufficient fit to the scaling of mean chromosome length as a function of chromosome number in real genomes. 相似文献
823.
Miquel Nadal María J. Clemente-Moreno Alicia V. Perera-Castro Margalida Roig-Oliver Yusuke Onoda Javier Gulías Jaume Flexas 《Ecology letters》2023,26(4):549-562
In recent years, attempts have been made in linking pressure–volume parameters and the leaf economics spectrum to expand our knowledge of the interrelationships among leaf traits. We provide theoretical and empirical evidence for the coordination of the turgor loss point and associated traits with net CO2 assimilation (An) and leaf mass per area (LMA). We measured gas exchange, pressure–volume curves and leaf structure in 45 ferns and angiosperms, and explored the anatomical and chemical basis of the key traits. We propose that the coordination observed between mass-based An, capacitance and the turgor loss point (πtlp) emerges from their shared link with leaf density (one of the components of LMA) and, specially, leaf saturated water content (LSWC), which in turn relates to cell size and nitrogen and carbon content. Thus, considering the components of LMA and LSWC in ecophysiological studies can provide a broader perspective on leaf structure and function. 相似文献
824.
825.
Scorpaena notata is an oviparous species with external fertilization that deposits its eggs in a gelatinous matrix. The internal epithelium of the ovarian wall is chiefly responsible for the production of this matrix, which is particularly abundant and viscous during the spawning period. The oocytes lack lipid droplets, so flotation and transport of the eggs is probably accomplished by means of the matrix that surrounds them. The ovarian stroma is situated along the centre of the gonad and the developing oocytes are connected to it by peduncles. The paucity and small size of the cortical alveoli of the oocytes are notable, as is the thinness of the zona radiata. These are characteristics that would be typical of viviparous species. The histological and ultrastructural observations lead to the conclusion that this species presents a type of oviparity more highly specialized than that of the majority of teleosts. 相似文献
826.
827.
Berkov Strahil Atanasova Mariyana Georgiev Borislav Bastida Jaume Doytchinova Irini 《Phytochemistry Reviews》2022,21(5):1415-1443
Phytochemistry Reviews - The AChE inhibitory activity of alkaloid extracts and compounds has been in the focus of research on the plants of Amaryllidoideae subfamily since the approval of... 相似文献
828.
In recent studies, we found that the ectopic testis from postpuberal boars with unilateral abdominal cryptorchidism does not produce sperm. Therefore, in these males, the seminal characteristics can be used as indicators of the activity of the scrotal testis and its epididymis and also the accessory glands. The semen quality (ejaculate volume, cell-rich fraction volume, sperm concentration, sperm vitality, sperm motility, sperm morphology and cephalic stability of spermatozoa) was evaluated in healthy postpuberal boars and in postpuberal boars with unilateral abdominal cryptorchidism on the right side. In comparison with the healthy boars, the unilateral abdominal cryptorchid boars showed a significant decrease of the ejaculate volume, sperm concentration and sperm motility. The low sperm concentration indicated that unilateral abdominal cryptorchidism severely impairs the sperm production of the scrotal testis. The decrease of ejaculate volume was attributed to an abnormal activity of the accessory glands. The alterations in sperm motility develop as a result of dysfunctions in the epididymal epithelium and/or the accessory glands. The sperm vitality, sperm morphology and cephalic stability of spermatozoa maintained normal values; therefore, at testicular level, despite the low sperm production, the germ cell differentiation is not disturbed. At epididymal level, the morphological maturation of spermatozoa is not altered. 相似文献