Search results for "cytokinin"
showing 10 items of 32 documents
Priming maritime pine megagametophytes during somatic embryogenesis improved plant adaptation to heat stress
2021
In the context of global climate change, forest tree research should be addressed to provide genotypes with increased resilience to high temperature events. These improved plants can be obtained by heat priming during somatic embryogenesis (SE), which would produce an epigenetic-mediated transgenerational memory. Thereby, we applied 37 °C or 50 °C to maritime pine (Pinus pinaster) megagametophytes and the obtained embryogenic masses went through the subsequent SE phases to produce plants that were further subjected to heat stress conditions. A putative transcription factor WRKY11 was upregulated in priming-derived embryonal masses, and also in the regenerated P37 and P50 plants, suggesting …
Hormonal and carbohydrate control of fruit set in avocado ‘Lamb Hass’. A question of the type of inflorescence?
2021
[EN] The avocado tree (Persea americana Mill.) has two types of shoots, indeterminate, which maintain vegetative development from an apical bud, and determinate, which do not have vegetative growth. Indeterminate shoots set fewer fruits than determinate ones, and significantly hasten physiological fruitlet abscission. The competition between vegetative and flower development is accepted as the most reasonable hypothesis to explain the differences. However, our results show that from anthesis until fruit set flowers of indeterminate inflorescences, both those remaining on the tree and those abscised, had a higher sucrose and C6 carbohydrate content than flowers of determinate ones and no dif…
The effects of meta-Topolin and benzyladenine on in vitro organogenesis from epicotyl cuttings of Troyer citrange (Citrus sinensis[L.] Osbeck ×Poncir…
2017
Citrus tristeza virus (CTV), worldwide considered as one of the worst disease affecting Citrus plants, produced great changes in citriculture, mainly because it made mandatory the turnover of the sensitive sour orange rootstock with virus resistant ones. Among them, Troyer citrange has become one of the most employed rootstocks, due to its CTV tolerance and to the positive characteristics induced to the scion fruit production. Unfortunately, in Italy, there is a scarcity of seed mother plants. Micropropagation can be a solution for this problem. Among the in vitro techniques allowing the production of good quality true-to-type plants, the regeneration from seedling epicotyl cuttings general…
Evaluation of some growth regulator effects on encapsulated in vitro-derived microcuttings of three Italian Ficus carica L. genotypes.
2017
In this study, the encapsulation technology based on the calcium alginate coating was applied to some Ficus carica L. genotypes. Uninodal microcuttings (3-4 mm long), excised from in vitro proliferating shoots of three Italian cultivars (‘Bifera’, ‘Palazzo’ and ‘Catalanisca’), were employed. The influence of three different plant growth regulators (PGRs): 6-benzylaminopurine (BAP), meta-topolin (MT) and zeatine (ZEA), added to the artificial endosperm, were evaluated. Particularly, the viability, regrowth and conversion parameters of the synthetic seeds were registered after 60 days from the sowing on a hormone-free medium. Results showed that the cultivars ‘Catalanisca’ and ‘Palazzo’ showe…
THE SYNTHESIS OF PLANT GROWTH STIMULATORS BY PHYTOPATHOGENIC BACTERIA AS FACTOR OF PATHOGENICITY
2018
The environmental changes significantly influence the microorganisms and affect their properties, leading them to take uncharacteristic ecological niches. This study has focused on the ability of phytopathogenic bacteria that belongs to the genera Pseudomonas, Curtobacterium, Ralstonia, Pantoea and Xanthomonas, which are able to cause various diseases of legumes, to produce extracellular phytohormones with stimulatory action in vitro. The qualitative and quantitative composition of extracellular auxins and cytokinins has been determined by spectrodensitometric thinlayer chromatography. This research revealed that the synthesis of plant growth promoting phytohormones that are agents of diffe…
Organogenesis and encapsulation of in vitro-derived propagules of Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirius trifoliata (L.) Raf]
2011
Due to widespread polyembryony, Citrus rootstocks are usually propagated by open-pollinated seed germination, although micropropagation offers many advantages. Encapsulation technology has recently attracted the interest of researchers in the field of plant propagation because it combines the advantages of zygotic or gamic seeds with those of micropropagation. In this study, we examined the encapsulation of Carrizo citrange uninodal microcuttings (3–4 mm long) and evaluated the influence of the calcium alginate coating, a short time storage at cold temperature, and different sowing substrates on the viability and regrowth of the explants. A secondary aim was to develop an efficient protocol…
Micropropagation of Globe Artichoke (Cynara cardunculus L. var. scolymus).
2013
The globe artichoke (Cynara cardunculus L. var. scolymus) is a perennial plant cultivated in the Mediterranean region and the Americas for its edible young flower heads. Although vegetative propagation by offshoots or by “ovoli” (underground dormant axillary buds) has been the primary method of propagation, the potential for the diffusion of diseases and the phenotypic variability can be very high. The propagation of this species by axillary shoot proliferation from in vitro cultured meristems produces systemic pathogen free plants and a higher multiplication rate as compared to that obtained by conventional agamic multiplication. Axillary shoot proliferation can be induced from excised sho…
The effect of explant cut and cytokinin type on micropropagation of fig (Ficus carica L.) 'Brown Turkey'
2017
This study was conducted to micropropagate 'Brown Turkey' fig, one of the most popular cultivars in California, USA for fresh and dried uses. Nodal segments cut lengthwise or not were cultured on Woody Plant Medium containing 0.3, 1.0 or 3.0 μM of N6 benzyladenine (BA) or kinetin in a 3 (concentrations) × 2 (cytokinins) × 2 (explant types) factorial experiment. 60% of explants became contaminated with various microbes when the standard protocol of washing shoots for 3 h under running tap water. Microbial contamination was nearly eliminated when the running water rinse and the use of an ascorbic acid dip were eliminated. Phenolic exudation was not a problem. Shoots grew longer with more leav…
Purification and identification of a cytokinin from moss callus cells.
1976
A cytokinin was isolated from the culture medium of callus cells of the moss hybridFunaria hygrometrica (L.) Sibth xPhyscomitrium piriforme Brid. The purification procedure included ethyl-acetate extraction, silver-salt precipitation, crystallization as picrate, and ion exchange chromatography. The structure of the cytokinin was confirmed as N(6)-(Δ(2)-isopentenyl)adenine by means of gas chromatography and mass spectrometry. The concentration of the compound in the culture medium was determined at ca. 10(-6) M.
Genetic instability in calamondin (Citrus madurensis Lour.) plants derived from somatic embryogenesis induced by diphenylurea derivative
2007
Somatic embryos were regenerated in vitro from calamondin style-stigma explants cultured in the presence of N (6)-benzylaminopurine (BAP) cytokinin and three synthetic phenylurea derivatives, N-(2-chloro-4-pyridyl)-N-phenylurea (4-CPPU), N-phenyl-N'-benzothiazol-6-ylurea (PBU) and N,N'-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU). The phenylurea derivative compounds tested at micromolar level (12 muM) were able to induce a percentage of responsive explants significantly higher from that obtained with BAP and hormone-free (HF) conditions. In order to verify the genetic stability of the regenerants, 27 plants coming from different embryogenic events were randomly selected from each different …