Investigation of different ontogenetic stages of Raillietiella sp. (Pentastomida: Cephalobaenida): suboral gland and frontal gland

2000 ◽  
Vol 86 (5) ◽  
pp. 385-400 ◽  
Author(s):  
Susanne Stender-Seidel ◽  
Gabriele Thomas ◽  
Wolfgang Böckeler
Keyword(s):  
Frontal Gland ◽  
Ontogenetic Stages

scholarly journals Effects of ontogenetic stage and leaf age on leaf functional traits and the relationships between traits in Pinus koraiensis

2021 ◽  
Author(s):  
Meng Ji ◽  
Guangze Jin ◽  
Zhili Liu
Keyword(s):  
Significant Positive Correlation ◽  
Leaf Age ◽  
Leaf Traits ◽  
Ontogenetic Stage ◽  
Pinus Koraiensis ◽  
Mature Trees ◽  
N Content ◽  
Ontogenetic Stages ◽  
Leaf N Content ◽  
Leaf N

AbstractInvestigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth. However, few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species. We divided 67 Pinus koraiensis Sieb. et Zucc. of various sizes (0.3–100 cm diameter at breast height, DBH) into four ontogenetic stages, i.e., young trees, middle-aged trees, mature trees and over-mature trees, and measured the leaf mass per area (LMA), leaf dry matter content (LDMC), and mass-based leaf nitrogen content (N) and phosphorus content (P) of each leaf age group for each sampled tree. One-way analysis of variance (ANOVA) was used to describe the variation in leaf traits by ontogenetic stage and leaf age. The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships. We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age. Most trait-trait relationships were consistent with the leaf economic spectrum (LES) at a global scale. Among them, leaf N content and LDMC showed a significant negative correlation, leaf N and P contents showed a significant positive correlation, and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage. LMA and LDMC showed a significant positive correlation, and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age. Additionally, there were no significant relationships between leaf N content and LMA in most groups, which is contrary to the expectation of the LES. Overall, in the early ontogenetic stages and leaf ages, the leaf traits tend to be related to a "low investment-quick returns" resource strategy. In contrast, in the late ontogenetic stages and leaf ages, they tend to be related to a "high investment-slow returns" resource strategy. Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.

Sensitivity of physiological and biochemical endpoints in early ontogenetic stages of crops under diclofenac and paracetamol treatments

2018 ◽  
Vol 26 (4) ◽  
pp. 3965-3979 ◽  
Author(s):  
Štěpán Zezulka ◽  
Marie Kummerová ◽  
Petr Babula ◽  
Markéta Hájková ◽  
Michal Oravec
Keyword(s):  
Ontogenetic Stages ◽  
Physiological And Biochemical

scholarly journals Variability of root traits in common bean genotypes at different levels of phosphorus supply and ontogenetic stages

2014 ◽  
Vol 38 (4) ◽  
pp. 1170-1180 ◽  
Author(s):  
Roberto dos Santos Trindade ◽  
Adelson Paulo Araújo
Keyword(s):  
Common Bean ◽  
Root Length ◽  
Root Traits ◽  
Growth Stages ◽  
Phenotypic Variance ◽  
Root Mass ◽  
Root Area ◽  
Ontogenetic Stages ◽  
Growth Habits ◽  
Selection Of

Selection of common bean (Phaseolus vulgaris L.) cultivars with enhanced root growth would be a strategy for increasing P uptake and grain yield in tropical soils, but the strong plasticity of root traits may compromise their inclusion in breeding programs. The aim of this study was to evaluate the magnitude of the genotypic variability of root traits in common bean plants at two ontogenetic stages and two soil P levels. Twenty-four common bean genotypes, comprising the four growth habits that exist in the species and two wild genotypes, were grown in 4 kg pots at two levels of applied P (20 and 80 mg kg-1) and harvested at the stages of pod setting and early pod filling. Root area and root length were measured by digital image analysis. Significant genotype × P level and genotype × harvest interactions in analysis of variance indicate that the genotypic variation of root traits depended on soil nutrient availability and the stage at which evaluation was made. Genotypes differed for taproot mass, basal and lateral root mass, root area and root length at both P levels and growth stages; differences in specific root area and length were small. Genotypes with growth habits II (upright indeterminate) and III (prostrate indeterminate) showed better adaptation to limited P supply than genotypes of groups I (determinate) and IV (indeterminate climbing). Between the two harvests, genotypes of groups II and III increased the mass of basal and lateral roots by 40 and 50 %, respectively, whereas genotypes of groups I and IV by only 7 and 19 %. Values of the genotypic coefficient of determination, which estimates the proportion of phenotypic variance resulting from genetic effects, were higher at early pod filling than at pod setting. Correlations between shoot mass and root mass, which could indicate indirect selection of root systems via aboveground biomass, were higher at early pod filling than at pod setting. The results indicate that selection for root traits in common bean genotypes should preferentially be performed at the early pod-filling stage.

scholarly journals The Influence Of Zinc On Seed Germination And Growth In The First Ontogenetic Stages In The Species Cucumis Melo L.

2015 ◽  
Vol 9 (2) ◽  
pp. 215-228 ◽  
Author(s):  
Anişoara Stratu ◽  
Naela Costică
Keyword(s):  
Seed Germination ◽  
Cucumis Melo ◽  
Growth Process ◽  
Lateral Roots ◽  
Tolerance Index ◽  
High Concentration ◽  
Seedling Vigour ◽  
Ontogenetic Stages ◽  
Vigour Index ◽  
Germination And Growth

AbstractThe paper presents the results of a study regarding the influence of treatment with zinc in different concentrations (50 mg∕l, 100 mg∕l, 200 mg ∕l, 300mg/l, 400 mg ∕l, 500 mg/l, 600 mg ∕l) on seed germination and growth in early ontogenetic stages ofCucumis meloL. We analyzed the following indicators: the percentage of germinated seeds; the length of root, the length of the hypocotyl and the length of the seedling; the number of the laterale roots; the tolerance index and the seedling vigor index. The results underline the specific variations of analysed indicators, depending on the concentrations used for the treatments of seeds. The concentrations used for treatment do not influence negatively the seed germination, but affected the seedling growth (especially the root elongation), the formation and growth process of lateral roots and the seedling vigour index. The delay effect of growth process is very pronounced in the case of high concentration.

scholarly journals Formation of Pattern and Diagnostic Instar Features of the Head in Caterpillars from Genus Peridea (Lepidoptera, Notodontidae)

2009 ◽  
Vol 43 (1) ◽  
pp. e-15-e-24
Author(s):  
I. Dolinskaya
Keyword(s):  
Pattern Formation ◽  
Larval Instar ◽  
Head Capsule ◽  
Diagnostic Character ◽  
Key To Species ◽  
Larval Instars ◽  
Diagnostic Characters ◽  
Ontogenetic Stages ◽  
First Time ◽  
Taxonomic Relations

Formation of Pattern and Diagnostic Instar Features of the Head in Caterpillars from Genus Peridea (Lepidoptera, Notodontidae) Pattern and colouration of caterpillar head of all larval instar of 7 species from genus Peridea Stephens, 1828 are studied. Formation of caterpillar head pattern in ontogenesis is discussed. Diagnostic characters, both specific and larval instars, are recorded for the first time. Key to species according to larval instars is given. Evidently, only larvae of the 1st instar demonstrate different directions in the pattern formation. This characteristic can be used for clearing of taxonomic relations in the genera and on the earliest ontogenetic stages (1st larval instar) only. In the following (2nd-5th) instars, the pattern became more or less of the same type. It depends on stripes shape or colouration only and can serve as good specific diagnostic character. To determine larval instar, both width of the head capsule and head pattern should be taken into account.

scholarly journals Morphological integration during postnatal ontogeny: implications for evolutionary biology

2021 ◽  
Author(s):  
Alex Hubbe ◽  
Guilherme Garcia ◽  
Harley Sebastiao ◽  
Arthur Porto ◽  
Fabio Andrade Machado ◽  
...  
Keyword(s):  
Evolutionary Biology ◽  
Additive Genetic Variance ◽  
Structural Similarity ◽  
Morphological Integration ◽  
Ontogenetic Stage ◽  
Postnatal Ontogeny ◽  
Phenotypic Variance ◽  
Skull Morphology ◽  
Genetic Covariance ◽  
Ontogenetic Stages

Understanding how development changes the genetic covariance of complex phenotypes is fundamental for the study of evolution. If the genetic covariance changes dramatically during postnatal ontogeny, one cannot infer confidently evolutionary responses based on the genetic covariance estimated from a single postnatal ontogenetic stage. Mammalian skull morphology is a common model system for studying the evolution of complex structures. These studies often involve estimating covariance between traits based on adult individuals. There is robust evidence that covariances changes during ontogeny. However, it is unknown whether differences in age-specific covariances can, in fact, bias evolutionary analyses made at subadult ages. To explore this issue, we sampled two marsupials from the order Didelphimorphia, and one precocial and one altricial placental at different stages of postnatal ontogeny. We calculated the phenotypic variance-covariance matrix (P-matrix) for each genus at these postnatal ontogenetic stages. Then, we compared within genus P-matrices and also P-matrices with available congeneric additive genetic variance-covariance matrices (G-matrices) using Random Skewers and the Krzanowsky projection methods. Our results show that the structural similarity between matrices is in general high (> 0.7). Our study supports that the G-matrix in therian mammals is conserved during most of the postnatal ontogeny. Thus it is feasible to study life-history changes and evolutionary responses based on the covariance estimated from a single ontogenetic stage. Our results also suggest that at least for some marsupials the G-matrix varies considerably prior to weaning, which does not invalidate our previous conclusion because specimens at this stage would experience striking differences in selective regimes than during later ontogenetic stages.

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