There are important but inconsistent differences in breeding site preference between the blow flies Lucilia sericata (Meigen, 1826) and L. cuprina (Wiedemann, 1830) (Diptera: Calliphoridae) that have significance for medical and veterinary science. These inconsistencies might arise from hybridisation. The species are difficult to distinguish using external morphology, although the male genitalia are distinctive and there are reliable molecular markers. Molecular evidence of modern hybridisation, derived from a newly developed nuclear marker, the period (per) gene, is presented here. This has implications for identifications of these species based on mtDNA, and may lead to an explanation of the medical and veterinary anomalies noted in these species., Kirstin Williams, Martin H. Villet., and Obsahuje seznam literatury
Greenhouse-grown susceptible 20-d-old seedlings of Theobroma cacao genotypes Catongo and tolerant genotype SCA6xCatongo were inoculated with a mixture of isolates of Crinipellis perniciosa, the causal agent of witches' broom. The characteristics of chlorophyll a fluorescence emission were monitored during leaf ontogeny using a portable system PAM-2000. In both inoculated and non-inoculated genotypes, significant differences were found for the effective quantum yield values of photosystem (PS) 2 (ΔF/Fm') at the B (7 to 14-d-old), D (21 to 30-d-old), and E (>30-d-old) stages of leaf development, and in quantum yield of the non-cyclic photosynthetic electron transport between PS2 and PS1 [qp(Fv/Fm)] and quencher efficiency [(Fm-Ft)/F0] at the B, C (15 to 20-d-old) and D stages. Intergenotypic differences were found only for the [qp(Fv/Fm)] and [(Fm-Ft)/F0] values at the E stage, and for fluorescence quenching (Fm-Ft) at the B and E stages. Highly significant inter- and intragenotype relationships were found between the rate of photosynthetic electron transport to PS2 (Amax) and maximum fluorescence during actinic irradiation (Fm'). Also, each of the highly significant relationships between (Fm-Ft) and Amax, [(Fm-Ft)/F0] and ΔF/Fm', and between [(Fm-Ft)/F0] and Amax were represented by a general model, independent of treatments. Therefore, alterations in energy distribution in the radiant energy collector complex interior of PS2 and reduction in absorption of photosynthetically active radiation were observed in the infected plants, mainly in the hybrid at the C stage. Also, variations were found in the noncyclic photosynthetic electron transport at the B and C stages in the infected Catongo. and I. C. F. Santos, A.-A. F. de Almeida, R. R. Valle.
Hybridization is particularly widespread in birds and can affect species status and recovery. The common quail Coturnix coturnix is a protected game species that has undergone significant population decrease due to habitat changes. The release of Japanese quail C. japonica and or hybrids for restocking has been occurring since the 1970’s. Both species have not developed reproductive isolating mechanisms and hybridization is occurring. Species distinction based on morphology and male callings is difficult. In this work cytochrome b gene and five microsatellite loci were used with the aim of establishing an identification test for quails sampled in Portugal. Cytochrome b gene revealed to be of promising use to identify the quail maternal lineage. Success in species assignment with the studied microsatellite loci was moderate to identify samples with suspicion of being hybrids with common quail maternal lineage.
Using mitochondrial DNA (mtDNA) variations, the phylogenetic position of Croatian populations of spined loaches within the European genus Cobitis was assessed. Spined loaches from the Matica, Neretva, Cetina, Zrmanja, Jadova, Sava, Drava and Kupa Rivers are included in two previously described groups: a) Cobitis sensu stricto group, and b) Adriatic group. The Danubian populations of C. elongatoides and its hybrids from the Kupa and Drava Rivers are related to the species included in the Cobitis s. str. group, whereas all other analysed populations clustered within the Adriatic group, which is divided into the “Bilineata”, “Elongata” and “Ohridana-zanandreai” clades. The Croatian spined loaches from the Adriatic watershed are included in the first two clades. Four mitochondrial lineages were revealed within the “Bilineata” clade: 1. ”C. bilineata” lineage containing loaches from the Zrmanja River and Italian and Spanish representatives of C. bilineata; 2. “Neretva-Cetina” lineage included loaches from the Cetina River (C. dalmatina) and the Neretva River (C. narentana); 3. “Jadova” lineage included specimens from the Jadova River; and 4. “Matica” lineage comprised spined loaches from the Matica River. Cobitis elongata from the Kupa and Drava Rivers belonged to the “Elongata” clade with two sublineages. Allozyme analyses of the C. taenia complex revealed the presence of both C. elongatoides and its all-female triploid hybrids in the Danube basin of Croatia.
Growth characteristics such as leaf area, fresh and dry mass, and shoot length, and physiological parameters such as photosynthetic and transpiration rates, stomatal conductance, and water use efficiency were reduced by blister blight significantly more in a susceptible tea clone TES-34 than in a tolerant clone SA-6. Also the contents of total sugars, nitrogen, amino acids, proteins, polyphenols, and catechin were reduced more in diseased plant leaves. However, the reduction was more prominent in susceptible than in tolerant clone. Among the different hybrids of tea, Assam hybrid UPASI-3 was highly susceptible to blister blight followed by Cambod UPASI-27 and China UPASI-9. Similarly, tea seedling cv. Caline was highly susceptible to blister blight when compared to tea clone UPASI-3. Susceptibility of tea cultivars to blister blight infection is connected with many physical barriers including leaf area, shoot length, moisture contents, and other physiological and biochemical parameters. and R. Premkumar, P. Ponmurugan, S. Manian.
Heterospecific hybrids often suffer from a lowered fitness relative to parental species. Contextdependent intrinsic costs of hybridization are partially due to a malfunction in cell biochemical machinery that affects metabolic rates at the organismal level. This study examines whether heterospecific hybridization influences the metabolic costs of maintenance in F1 hybrids between closely related newts, Triturus carnifex and T. dobrogicus. When controlled for body size, oxygen consumption in hybrid newts was 59-76 % higher than in the parental species. This suggests that high standard metabolic rates in hybrids may contribute to thecosts of hybridization in newts.
Chlorophyll (Chl) content, photochemical activity of chloroplasts as well as photosynthetic and crop productivity were studied in different winter hexaploid Triticale (xTriticosecale Witt.) lines and their F1 hybrids. Heterosis enhanced Chl content, photosynthetic potential, photosynthetic productivity, and grain yield only in several F1 hybrids of Triticale. Indication in some genotypes of close correlations among morphological structure, Chl content, photochemical activity of chloroplasts, photosynthetic potential, and plant productivity may be used in breeding practice of Triticale. and S. N. Kabanova ... [et al.].
Measurements of ultrastructural characteristics of chloroplast thylakoids are important for studies of ontogenic or ecological limitations of leaf photosynthetic functions. Most frequently, volumetric proportion of thylakoids in the chloroplast is measured; however, such measurement does not provide a direct information about the surface area of thylakoids which is most important from the functional point of view. Therefore, we adapted the stereological method using "local vertical windows" for estimating thylakoid surface area in the chloroplast volume and compared thus obtained surface density results with results of conventional volume density measurements. The methods were tested in the study of chloroplast ultrastructure in the leaves of plants of two maize (Zea mays L.) hybrid combinations, 2013×CE810 and CE704×CE810, developing in control and chilling conditions. Correlation analysis revealed a tight relationship between the granal/intergranal thylakoid surface density and volume density results, both indicating that under chilling conditions the development of the system of thylakoids in maize leaves is suppressed, while the difference is more pronounced in CE704 than in CE810 genotype, known to have a better photosynthetic performance. and L. Kubínová, J. Kutík.