Search results for "PLANT PHYSIOLOGY"
showing 10 items of 118 documents
Untargeted metabolomics of rind essential oils allowed to differentiate two closely related clementine varieties
2021
[EN] Chemical characterization of clementine varieties (Citrus clementina Hort. ex Tan.) essential oils (EO) can lead to variety identification and valorization of their potential use in food and aroma industries. The goal of this study was the chemometric discrimination between two very closely related and morphologically identical clementine varieties, Clemenules (NL) and Clemenpons (PO), based on their rind EO, to identify the differential volatile organic compounds (VOCs) and to determine their antioxidant capacity. EO rind volatile profile was determined by gas chromatography coupled to mass spectrometry in Citrus fruit at different ripening stages grown two independent years in two di…
Growth and activities of enzymes of primary metabolism in batch cultures of Catharanthus roseus cell suspension under different pCO2 conditions
1988
In vitro enzyme activities of glycolysis, pentose-phosphate pathway and dark CO2 fixation were assayed in batch cultures of heterotrophic Catharanthus roseus cells under various gassing rates and partial pressures of carbon dioxide. Detrimental effects of low pCO2 culture conditions on the growth characteristics could be linked to marked changes in levels of enzymes of primary metabolism during growth. The enzyme levels observed during the early stages of growth were found to be more stable when a constant pCO2 (20 mbar) was maintained and enabled exponential growth to be reached more rapidly. The importance of carbon dioxide as a “conditioning factor” of the culture medium is discussed.
Ernesta Foldāta piedzīvojumi Venecuēlā un dzeja par to
2019
Latvijas Universitātes Goda doktora, Latvijas Zinātņu Akadēmijas Ārzemju Goda locekļa, Venecuēlas Centrālās Universitātes un Nacionālo parku institūta emeritētā profesora, orhideju pētnieka Ernesta Foldāta (1925-2003) apraksti par piedzīvojumiem Venecuēlā un dzeja par to.
Multitrophic interactions in the rhizosphere Rhizosphere microbiology: at the interface of many disciplines and expertises.
2008
The rhizosphere – the soil compartment influenced by the root, including the root itself – is the most-active microbial habitat in soils. Indeed, the release by plant roots of a significant part of their photosynthates promotes microbial abundance and activities in the rhizosphere. This investment made by plants is paid back by microbial functions, which contribute to plant nutrition and protection against soil-borne diseases. Indeed, rhizosphere microorganisms play a major role in plant growth and health and, …
Mode of action of herbicidal derivatives of aminomethylenebisphosphonic acid. I. Physiologic activity and inhibition of anthocyanin biosynthesis
1996
N-Pyridylaminomethylenebisphosphonic acids constitute a class of promising herbicides. Since their mode of action at the cellular level is still poorly understood, we studied the influence of N-pyridylaminomethylenebisphosphonic acids on plant growth, at the whole plant and undifferentiated tissue levels, using seedlings and cell suspension cultures of mono- and dicotyledonous species. These compounds exhibited strong herbicidal properties, being equipotent with the popular herbicide glyphosate. Since they also depressed buckweed anthocyanin biosynthesis, the shikimate pathway could represent a site of action of N-pyridylaminomethylenebisphosphonic acids.
Isolation and culture of grape vine cv. Chardonnay leaf protoplasts
1990
Experimental conditions were established that resulted in high yields and good viability of the protoplasts obtained from leaves of Vitis vinifera, cv. Chardonnay regenerated in vitro by somatic embryogenesis. The effect of factors of the culture medium and various environmental conditions upon the frequency of cell division has been examined, and a method of culture is described by which protoplasts were induced to begin division. Most protoplasts obtained in this way regenerated cell walls within the first few days and cell division occurred after 10 days of culture in a liquid medium. Some cells have divided two or even three times. Nevertheless, the cells did not continue dividing beyon…
The effect of light quality on anther culture of Citrus clementina Hort. ex Tan.
2005
This pre lim i nary re search re ports re sults on the in flu ence of light qual ity on an ther cul ture of Cit rus clementina Hort. ex Tan., cultivar Nules. Af ter one month of cul ti va tion in dark - ness, four light quali ties were tested: White, Red, Far-Red and Blue. Con tin u ous Dark ness and White light un der photoperiod of 16 hrs were used as a con trol con di tions. Ga metic embryoids and embryogenic cal lus were ob tained only un der photoperiodic con di tions of White light, sug gest ing that the al - ter na tion of light and dark can be used for the pro cess of ga - metic embryogenesis in Cit rus.
Potential use of new diphenylurea derivatives in micropropagation of Capparis spinosa L.
2011
A protocol for in vitro multiplication of caper (Capparis spinosa L. subsp. rupestris) from nodal segments collected from mature plants was developed. For shoot multiplication, one auxin (indol-3-butyric acid, IBA) and cytokinins of two different classes were used: the N6-substituted adenine derivatives 6-benzylamino purine (BAP), and the two synthetic phenylurea derivatives N-phenyl-N′-benzothiazol-6-ylurea (PBU) and N-phenyl-N′-(1,2,3-thidiazol-5-yl) urea (thidiazuron, TDZ). Maximum shoot production was achieved from explants cultured with the adeninic cytokinin BAP (4 μM) and the auxin IBA (0.5 μM). New shoots longer than 1 cm were used for rooting. To induce root formation, three auxins…
Helēnas Ledus - Starcas herbāriji
2022
Raksts par Helēnas Ledus-Starcas (1915 – 2005) herbārijiem Herbarium Latvicum (RIG II), kas glabājas Latvjas Universitātes Muzeja Botānikas un mikoloģijas kolekcijās.
Fizioloģiskais pamats parastās priedes (Pinus sylvestris) pavairošanai audu kultūrā
2008
Fizioloģiskais pamats parastās priedes (Pinus sylvestris) pavairošanai audu kultūrā Darba mērķis - veidot fizioloģisko pamatu pieaugušas parastās priedes Pinus sylvestris L. pavairošanai ar audu kultūru metodi. Piemērotākais laiks pieaugušu parasto priežu ievadīšanai kultūrā bija no jūlija līdz oktobra beigām. Fizioloģiskā miera stāvoklī esošu priežu pumpuru morfogēno kompetenci audu kultūrā varēja palielināt, pumpurus pirms ievadīšanas kultūrā uzglabājot pazeminātā temperatūrā. Pazemināta vai stabila oksidatīvo fermentu aktivitāte korelēja ar paaugstinātu audu morfogēno kompetenci in vitro. Priežu pumpuru kultivēšanai piemērotāka ir skāba iniciālā barotne. In vitro kultivētu pieaugušu prie…