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.
A total of 181 faecal samples were collected from wild cervids in two regions of Poland. Giardia cysts were detected in one faecal specimen from red deer and in two samples from roe deer. Fragments of the β-giardin (bg) triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes were successfully amplified from the Giardia isolate obtained from red deer, whereas only amplicons of bg and gdh were obtained from Giardia isolates derived from two roe deer. The result of genotyping and phylogenetic analysis showed that the G. duodenalis isolate from red deer belonged to sub-assemblage AIII, which has never been identified in humans, whereas isolates from roe deer clustered within zoonotic sub-assemblage AI. Further studies are necessary to explain which Giardia assemblages and/or sub-assemblages occur in wild cervids in various regions of the world. Moreover, the impact of Giardia infection on the health of wild cervids should also be elucidated.
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.].
The activity of photosystems (PS) 1 and 2, together with the content and ratio of photosynthetic pigments, were measured in three inbred lines and two F1 hybrids of maize (Zea mays L.), grown in either optimum or low temperature (LT) conditions. The ability of chilling-stressed plants to deal with the negative effects of long-term exposure to LT and to recover the efficiency of photosynthetic apparatus after their return to optimum temperatures was examined during spring and autumn seasons. The aim was to analyse the possible differences between the rapid and gradual onset of LT on the response of young maize plants to chilling stress. The distinctive superiority of hybrids over their parental lines, found during the exposure of maize plants to LT, was not always retained after the return of chilling-stressed plants to optimum growth conditions. The response of individual genotypes to chilling stress, as well as their ability to recover the photosynthetic efficiency from the cold-induced damage, strongly depended also on the duration and the rapidity of the onset of LT. and D. Holá ... [et al.].
The primary aim was to determine frequencies of mutations related to risk of venous thrombosis in healthy Caucasians in Central Bohemia. In a cohort of 1527 healthy individuals the frequency of risk alleles for the mutations FV Leiden and FII 20210G>A was 4.5 % and 1.3 %, respectively. Frequency of 4G PAI-1 allele was 55.5 %. Genotype frequencies were: GG 91.03 %, GA 8.91 %, an d AA 0.07 % for FV Leiden; GG 97.45 %, GA 2.49 %, and AA 0.07 % for FII 20210G>A; 4G/4G 30.26 %, 4G/5G 50.56 %, and 5G/5G 19.19 % for PAI-1. Frequency of the risk allele A in polymorphism SERPINC1 (IVS +141G >A) was 11.3 %, and frequencies of genotypes were as follows: GG 78.36 %, GA 20.66 %, and AA 0.98 %. Frequency of the risk allele T for polymorphism GP6 13254T>C was 87.7 %, and frequencies of genotypes were as follows: TT 77.14 %, TC 21.15 %, and CC 1.70 %. Frequency of the risk allele A in polymorphism CYP4V2 (Lys259Gln ) was 65.2 %, and frequencies of genotypes were: CC 12.25 %, CA 45.12 %, and AA 42.63 %. All observed genotypes and alleles frequencies were without gender differences. Their occurrences confirm a relatively high prevalence of hereditary thrombophilia predisposition in the Czech Republic., T. Kvasnička ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Influence of moderate chilling stress on vascular bundle sheath cell (BSC) and especially mesophyll cell (MC) chloroplasts of mature maize leaves was studied by electron microscopy and stereology. Plants of two inbred lines of maize, differing in their photosynthetic activity, and their F1 hybrids were cultivated during autumn in heated or unheated glasshouse. Generally, chilling temperatures resulted mainly in the decrease in stereological volume density (VD) of both granal and intergranal thylakoids of MC chloroplasts, while the ratio of granal to all thylakoids (granality) was less affected. The VD of peripheral reticulum and plastoglobuli usually increased after cold treatment of plants. The volume of MC chloroplasts usually increased under chilling stress, the shape of the chloroplasts changed only slightly. The ultra-structure of chloroplasts differed between individual genotypes; chilling-stressed hybrid plants showed positive heterosis particularly in the granal thylakoids' VD of MC chloroplasts. and J. Kutík ... [et al.].