175 research outputs found
In vitro effects of regulators on growth and morphogenesis of Ocimum basilicum L. ‘Alfavaca Green’ stem apexes
Large-scale cultivation of contamination free plants requires a good standardization
protocol and production methods. Basil is widely used for cosmetics, food and pharmaceutical
industries as it is rich in many bioactive compounds. This present study aimed to evaluate the
growth and in vitro anatomical aspects of apical buds of basil grown under
different concentrations rowth regulators like: NAA (Naphthalenoacetic Acid), BAP
(6-benzylaminopurine), and KIN (Kinetin). The in vitro establishment was evaluated every 20
days to calculate the, the percentage of plants with calluses, appearance of the roots, any abnormal
seedlings, any oxidized seedlings, and the number of sprouts per plant. Growth, physiological,
and morpho-anatomical evaluations were performed at 80 days. Basal callogenesis was observed
when cytokinin’s and auxins are used in combination. Auxin treatments caused hyperhydricity in
the stems and leaves. Medium A2 (0.05 mg L
-1 of NAA and 0.1 mg L
-1 of BAP), and A3
(0.05 mg L
-1 of NAA and 0.1 mg L
-1 of KIN) resulted in the best development of basil plants,
cultivar ‘Alfavaca Green’. The A2 produced plants with greater numbers of leaves, an average
bud length of 59.81 mm, and the best root properties. A2 and A1 have a higher percentage of
hyperhydricity (83 and 67%). The A3 resulted in an acceptable number of leaves (range: 21–39),
and this treatment produced the best shoot properties as well as fewer plants with hyperhydricity.
In addition, the A3 treatment produced plants with a shoot length, high shoot fresh and dry mass
(2.82 and 0.23 g), high chlorophyll index and leaf anatomy that was similar to the control.
Excluding the control, the other treatments presented more than 90% of the explants with calluses
in their bases
Impacts on water, soil and plants from the abandoned Miguel Vacas copper mine, Portugal
Soil, water and plant geochemistry was studied around the Miguel Vacas copper mine (Alentejo, SE Portugal), which stopped
its exploitation and processing activities in 1991. After closure waste-rock piles remained exposed to weathering. The copper ore
was mainly composed of copper phosphates and carbonates. Remediation actions were insufficient to prevent the spreading of
waste-rock materials to surrounding farmed fields. The latter caused contamination of soils and water. Based on overall
characteristics water from wells and surface stream water mostly can be classified as of the sulphate magnesium type. The
application of a chemical equilibrium model to the sampled water showed that copper, phosphate and sulphate concentrations are
controlled by copper(II) secondary minerals (pseudomalachite, libethenite and malachite) and gypsum. Nevertheless, groundwater
can be used for irrigation and cattle based on quality parameters.
Soils and plants (Prunus domestica L., Olea europaea L. spp. europaea and Quercus ilex L.) were collected southeast of the
open pit and the exploitation substructures. The soils located in the influence of drainage water that percolated through waste
material or exploitation substructures were contaminated with Cu, and Ni was close to the maximum value allowed by Portuguese
legislation. These soils, however, did not show elevated Zn and Mn concentrations. The trace element content in plants was within
the normal range, with Q. ilex being able to accumulate Mn and to some extent also Ni. Dispersion of trace elements seemed to be
limited to a distance 1500 m down from the waste dumps in southeastern direction
Root system traits and its relationship with photosynthesis and productivity in four maize genotypes under drought
The present study combined evaluations of agronomic parameters such as roots morphometry (using the WinRhizo program) and leaf gas exchange, in order to detect features in the root system which allow the maintenance of photosynthetic rates and productivity in four maize genotypes contrasting for tolerance to water deficit (WD), two tolerant (DKB 390 and BRS1055) and two sensitive (BRS 1010 and 2B710). The genotypes showed similar tolerance to dehydration of leaf tissue, but the tolerant genotypes DKB 390 and BRS1055 presented higher photosynthetic rate and yield compared to the sensitive BRS 1010 and 2B710. Nevertheless, divergent strategies of adaptation to drought among tolerant genotypes were observed. The genotype DKB 390 presented physiological mechanisms in shoots responsible for minimizing water loss, which decreases the dependence of root adjustments to increase the absorption of water. In turn, the BRS 1055 genotype showed a drought avoidance strategy by producing fine roots associated with a higher leaf area
Copper modulates the biochemical and enzymatic activity and growth of tomato cultivars grown in vitro
Received: August 25th, 2020 ; Accepted: December 17th, 2020 ; Published: February 09th, 2021 ; Correspondence: [email protected] (Cu) is a micronutrient that is neglected for tomato growth. This study sought
to identify the effects of exposure to Cu on the growth and biochemical activity of two tomato
cultivars. Tomato seeds of ‘Carolina’ and ‘Cereja’ cultivars were disinfected and inoculated in
MS medium plus copper sulfate concentrations (CuSO4) (default MS, 25, 50, and 100 µm) and
had their growth monitored for 30 days. It was estimated that the growth and biomass
accumulation of tomato plants ‘Carolina’ and ‘Cereja’, both from the aerial part and the roots,
were benefited by 25 e 50 µm of CuSO4. However, it was observed that these concentrations were
inefficient in controlling hyperhydricity and leaf deformation. There was a reduction of these
phenomena in the treatment with 100 µm, in both cultivars. Tomato of ‘Carolina’ cultivar
subjected to 100 µm showed an increase in anthocyanins and superoxide dismutase (SOD)
activity in the root system. There was a reduction of catalase (CAT) activity in shoots exposed to
Cu. ‘Cereja’ tomatoes subjected to 100 µm showed an increase in CAT and SOD activity in
shoots and roots, respectively. It was concluded that the ‘Carolina’ and ‘Cereja’ tomatoes have
their growth impaired when exposed to 100 µm CuSO4. Concentrations higher than 50 µm of
CuSO4 cause an increase in the antioxidant activity in the shoot of tomato plants from the
‘Carolina’ cultivar. Concentrations higher than 50 µm CuSO4 increase SOD activity in the root
system of tomato plants from the ‘Cereja’ cultivar
Root system traits and its relationship with photosynthesis and productivity in four maize genotypes under drought
População de Rhizobium spp. e ocorrência de micorriza V.A. em cultivos de essências florestais
The occurrence of nodulation and mycorrhizal association in several forest tree plantations at reserva Ducke/INPA (km 25 M 010-AM-Brazil) was investigated. The species of indigenous forest trees studied were: Cedrelinga catenaeformis (cedroana), Calophyllum brasiliense (jacareuba), Dipterix odorata (cumaru), Carapa guianensis (andiroba), Dipterix potiphylla (cumarurama), Goupia glabra (cupiúba), Tabebuia serratifolia (pau d'arco), Clarisía racemosa (Guariúba-folha-fina), Pithecellobium racemosum (angelim-rajado), Vouacapoua pallidior (acapu), Eperua bijuga (muirapiranga) and Diplotropis sp. (sucupira). The only leguminous trees that showed nodules were C. catenaeformis and V. pallidior on clay and sandy soil respectively. The lack of nodulation was not correlated with Rhizobium populations. The amount of V.A. mycorrhizal spores in the soil were not seen to be correlated with root infection. All tree species showed V.A. mycorrhizal infection, and one of the higher infection in C. catenaeformis.São apresentados resultados da ocorrência da nodulação e associação micorrízica em várias espécies florestais arbóreas da Reserva Ducke/INPA (km 27 M 010-AM-Brasil). As espécies estudadas foram: Cedrelinga catenaeformis (Cedrorana), Calophylium brasiliense (jacareuba), Dipterix odorata (cumaru), Carapa guianensis (andiroba), Dipterix potiphylla (cumarurama), Goupia glabra (cupiúba), Tabebuia serratifolia (pau d'arco), Clarisia racemosa (Guariúba-folha-fina), Pithecellobium racemosum (angelim-rajado), Vouacapoua pallidior (acapu), Eperua bijuga (muirapiranga) e Diplotropis sp. (sucupira). Somente as espécies C. catenaeformis e V. pallidior apresentaram nódulos em solo argiloso e arenoso, respectivamente. A falta de nodulação não foi correlacionada com a população de Rhizobium no solo. A quantidade de esporos de micorrizas vesísulo-arbusculares no solo, também, não correlacionou com a infecção de raízes. Todas as espécies mostraram infecção com micorrizas, sendo maior em C. catenaeformis
Reproduction of the blue jack mackerel, Trachurus picturatus, in western Portugal: microscopic gonad analysis reveals indeterminate fecundity and skipped spawning patterns
Blue jack mackerel, Trachurus picturatus, is the fifth most landed fish species in mainland Portugal, but
information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens
were collected from commercial vessels to clarify the reproductive strategy of the T. picturatus population
off the west coast of Portugal. The proportion and length range of males and females were similar. Only
three of the specimens collected were categorized as immature, indicating that the fish caught in the
fishery are primarily mature. The spawning season lasted from late January until the end of March, with
gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated
batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low
number of females showing direct evidence of imminent or recent spawning suggests a low number
of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary
abnormalities including parasitic infection by Kudoa species, atretic structures and skipped spawning
events. This study highlights the importance of accounting for skipped spawning events and ovary
abnormalities in the management of species fisheries.info:eu-repo/semantics/publishedVersio
Large atom number dual-species magneto-optical trap for fermionic 6Li and 40K atoms
We present the design, implementation and characterization of a dual-species
magneto-optical trap (MOT) for fermionic 6Li and 40K atoms with large atom
numbers. The MOT simultaneously contains 5.2x10^9 6Li-atoms and 8.0x10^9
40K-atoms, which are continuously loaded by a Zeeman slower for 6Li and a
2D-MOT for 40K. The atom sources induce capture rates of 1.2x10^9 6Li-atoms/s
and 1.4x10^9 40K-atoms/s. Trap losses due to light-induced interspecies
collisions of ~65% were observed and could be minimized to ~10% by using low
magnetic field gradients and low light powers in the repumping light of both
atomic species. The described system represents the starting point for the
production of a large-atom number quantum degenerate Fermi-Fermi mixture
- …