Photochemical activity of isolated mesophyll chloroplasts was measured as Hill reaction activity (HRA) and photosystem 1 (PS1) activity in three diallel crosses of maize (Zea mays L.) inbred lines and F1 hybrids. Statistically significant differences between genotypes together with positive heterotic effect in F1 generation were found for both traits studied. These differences were more pronounced when HRA or PS1 activity was expressed per leaf area unit or dry matter unit compared to the expression per chlorophyll content unit. Analysis of variance showed that both the genetic and non-genetic components of variation in the photochemical activity of isolated mesophyll chloroplasts are present in all three diallel crosses examined. The positive heterosis in F1 hybrids probably arises from non-additive genetic effects of a positive dominance type. Additive genetic effects were also statistically highly significant. We found no differences between reciprocal crosses. and D. Holá ... [et al.].
The genus Triaenops has been considered monospecific in its a frican and Middle Eastern range (T. persicus), while three other species have been recognised as endemic to Madagascar (T. menamena, T. furculus, and T. auritus), and another to the western Seychelles (T. pauliani). We analysed representative samples of T. persicus from East Africa and the Middle East using both morphological and molecular genetics approaches and compared them with most of the available type material of species of this genus. Morphological comparisons revealed four distinct morphotypes in the set of examined specimens; one in Africa, the others in the Middle East. The Middle Eastern morphotypes differed mainly in size, while the allopatric African form showed differences in skull shape. Two of three Arabian morphotypes occur in sympatry. Cytochrome b gene-based molecular analysis revealed significant divergences (K2P distance 6.4–8.1% in complete cyt b sequence) among most of the morphotypes. Therefore, we propose a split of the current T. persicus rank into three species: T. afer in Africa, and T. persicus and T. parvus sp. nov. in the Middle east. The results of the molecular analysis also indicated relatively close proximity of the Malagasy T. menamena to Arabian T. persicus, suggesting a northern route of colonisation of Madagascar from populations from the Middle east or north-eastern Africa as a plausible alternative to presumed colonisation from east Africa. Due to a considerable genetic distance (21.6–26.2% in 731 bp sequence of cyt b) and substantial morphological differences from the continental forms of Triaenops as well as from Malagasy T. menamena, we propose generic status (Paratriaenops gen. nov.) for the group of Malagasy species, T. furculus, T. auritus, and T. pauliani. We separated the genera Triaenops and Paratriaenops gen. nov. from other hipposiderid bats into Triaenopini trib. nov. recognising their isolated position within the family Hipposideridae Lydekker, 1891.
Genetic analysis of the content of light-harvesting complexes of thylakoid membranes was accomplished for the first time during the study of intraspecific variation in photosynthetic characteristics. The existence of genetically determined differences between genotypes together with positive heterosis in F1 generation was demonstrated.
Young plants of maize inbred lines CE777, CE704, and CE810 and their F1 hybrids displaying a positive heterotic effect in various photosynthetic characteristics were exposed to low temperature during their early growth developmental stage. The photochemical activity of isolated mesophyll chloroplasts and the contents of photosynthetic pigments in leaves of stressed and non-stressed plants were compared with the aim to find out the possible changes in the relationship between parents and hybrids, and to determine the genetic basis of heterosis in F1 generation. Strong decrease in the content of chlorophylls was observed for all genotypes examined when plants were subjected to low growth temperature. Similar change was recorded for Hill reaction activity (HRA) of inbred lines but not of their F1 hybrids, and no significant response at all was found for photosystem 1 (PS1) activity or the total carotenoids content. The intraspecific variation due to differences between genotypes was found for most of photosynthetic characteristics examined. This variation was caused by the additive and dominance genetic effects. Positive dominance was the main cause of positive heterosis in HRA and in the contents of photosynthetic pigments and was much more pronounced in the stressed plants compared to the non-stressed ones. The maternal additive effects participated in the inheritance of contents of photosynthetic pigments in plants exposed to low temperature, too. and M. Körnerová, D. Holá.
The response of selected photosynthetic and morphological parameters of plants to drought was examined in 5 inbred lines of maize (Zea mays L.) and their 10 F1 hybrids. The aim of the study was to establish whether the photosynthetic performance of parental genotypes under drought conditions correlates with the performance of their progeny and whether the net photosynthetic rate, the chlorophyll fluorescence parameters or the content of photosynthetic pigments could be used as reliable physiological markers for early breeding generations. The relative importance of the additive and the nonadditive (dominance, maternal) genetic effects in the inheritance of these parameters was also assessed by means of the quantitative genetics analysis. The results showed that the nonadditive genetic effects associated with a particular combination of genotypes or a particular direction of crossing are at least equally and often even more important as the additivity and that these genetic effects almost totally change with the exposure of plants to drought conditions. This was reflected in the inability to predict the response of F1 hybrids to drought on the basis of the photosynthetic performance of their parents, which indicates that the practical usability of such parameters in maize breeding programs is rather limited. and D. Holá ... [et al.].
A detection dog and handler team were used to recover scats in areas newly colonized by wolves outside the Alpine mountains of France between October 2018 and May 2019. Survey areas were classified as occupied by a resident wolf pack (WP) or dispersers (no-WP). The efficiency of monitoring by a targeted dog-handler team was compared to opportunistic monitoring by trained observers. Use of the detection dog allowed up to 99.6% time savings relative to monitoring by trained observers. Wolf scats found by the dog represented 82.1% of genetically confirmed samples in the 12 sample units (each being 10 × 10 km) monitored by both trained observers and the dog-handler team. Occupancy modelling was used to estimate wolf detection probabilities. Ten kilometres of survey with the dog were required to reach a 98% detection probability in WP territories and 20 km to reach 96% in no-WP areas. By contrast, two years of opportunistic monitoring by trained observers were required to obtain a 90% and 76% probability of detecting wolves in WP and no-WP areas, respectively. The use of the detection dog via dog-team surveys greatly increased the collection of viable samples for genetic analysis and individual genotype identification. Our study offers further confirmation that dog-handler teams can be very effective at locating scats from target carnivores, to supplement or complement human search efforts.