1,721,046 research outputs found
Microscopia ottica
No full textIl capitolo descrive le basi teoriche e le principali tecniche della microscopia ottica in campo vegetale
Microscopia elettronica
No full textIl capitolo descrive le basi teoriche e le principali tecniche della microscopia elettronica applicata allo studio della biologia delle piant
Revised typification of the name Bupleurum gracile DC. var rollii Montel. (Apiaceae) and comparison with B. asperuloides Heldr., B. gracile D'Urv., B. marschallianum C. A. Mey and B. uechtritzianum S. Stoyanov
No full textBupleurum gracile (M. Bieb.) DC. var. rollii Montel. ( ≡ Bupleurum rollii [Montel.] Moraldo) is lectotypified on a herbarium specimen kept in RO, revising the previous typification by S. Snogerup and B. Snogerup. An isolectotypes and 14 syntypes are also selected. Infraspecific variability and comparison with related Eastern species B. asperuloides Heldr. B. uechtritzianum S. Stoyanov and B. marschallianum C. A. Mey plus B. gracile D'Urv. are studied using morphometric and anatomical data. Notes on the ecology and distribution of the Italian endemic taxon are also provided
CPT accumulation in the fruit and during early phases of plant development in Camptotheca acuminata Decaisne (Nyssaceae)
No full textWe describe the dynamics of camplothecin (CPT) accumulation during the early phases of plant development in Camptotheca acuminata. TLC and HPLC analyses were performed on the entire mature fruit and all of its parts and on the organs of seedlings in different developmental stages. In the mature fruit, the CPT content was relatively high (2.83 mg g(-1) DW); it was accumulated especially in the endosperm (1.82 mg g(-1) DW) and embryo (1.10 mg g(-1) DW). Regarding seedlings. CPT was present in all of the organs, at all developmental stages. In the cotyledons, content was greatest in the early developmental stages (4.23 mg g(-1) DW) and drastically decreased once the organ reached maturity (0.34 mg g(-1) DW). A similar trend was observed for the true leaves. The results suggest that CPT is translocated from the organs at,in advanced developmental stage to those at an early stage
La conservazione ex situ della biodiversità delle specie vegetali spontanee e coltivate in Italia: stato dell’arte, criticità e azioni da compiere
No full textMetaboliti secondari ad attività antitumorale in Camptotheca acuminata Decne, e loro localizzazione cellulare.
No full textCellular localisation of the anti-cancer drug camptothecin in Camptotheca acuminata Decne (Nyssaceae)
No full textIn Camptotheca acuminata, we studied the cellular sites of accumulation of the alkaloid camptothecin (CPT), in both plants grown in the field and those grown in a greenhouse, subjecting the latter to stress (i.e., draught, nutritional deficit, and pruning). Fresh sections of the leaf, stem, and root were analysed for the presence of CPT by examining the autofluorescence that the CPT molecule emits when exposed to UV radiation. In the plants grown in the field, CPT was observed only rarely. In the greenhouse plants, CPT had accumulated in crystalline form in the vacuole of specialised cells (i.e., segregator idioblasts), which were not morphologically distinguishable from the cells of the surrounding tissues. In the organs examined, the segregator idioblasts were localised in parenchymatic and epidermal tissues. CPT crystals were also detected in the glandular trichomes on both the stem and leaf
THE BIZARRE CARNIVOROUS PLANT GENLISEA: IN VITRO PROPAGATION AND MICROSCOPICAL INVESTIGATION OF GLANDULAR STRUCTURES
No full textGenlisea is a genus of small tropical carnivorous plants distributed throughout Africa and central-south
America, growing in wet terrestrial to semi-aquatic environments (1). The main feature of Genlisea is the
absence of a true root and a remarkable heterophylly: the plant possesses aerial photosynthetic leaves, or
“nomophylls”, and subterranean tubular achlorophyllous leaves called “rhizophylls”, which are and
specialized for trapping preys.
Genlisea possesses a trapping mechanism comparable to an “eel trap” or a “lobster pot”, that capture a wide
range of soil organisms, ranging from unicellular organism as protozoa and algae, to metazoans as
crustaceans, mites and nematodes. Preys enters the rhizophylls through openings of the arms and then they
can move in a single direction due to the presence of detentive hairs orientated towards the trap vesicle. The
vesicle, also called "stomach", is a swelling of the rhizophyll where the digestion and uptake of released
nutrients occur. On interior surface of the vesicle there are glands, which are supposed to be responsible for
the secretion of digestive enzymes and the absorption nutritional elements.
Several species coming from Africa (ie G. hispidula, G. subglabra and G. margaretae) and Central and
South America (ie G. pygmaea and G. oxycentron) are currently grown in pots in a climatic chamber. The
first objective of this research is the in vitro propagation of Genlisea spp. Preliminary data showed that leaf
explants do not survive the sterilization procedure. Consequently, fresh seeds have been harvested from potsgrown
plants. The seeds showed resistance to 10% sodium hypochlorite, whereas they have lose
germinability after pretreatment whit 70% ethanol. Preliminary results obtained with G. hispidula showed a
rate of germination ranging from 8% to 17%, depending on whether the sterilization treatment were done
directly on seeds or on the entire capsule. The germination were observed 10 days after the inoculum on
hormone-free culture medium. In the early stages of seedling growth it has been observed a peculiar
developmental pattern of the shoot apical meristem, which generated alternatively nomophyll and rhizophyll
primordia. This pattern is abolished by the presence of cytokinin (BAP) that, even at relatively low
concentrations, prevent the development of the rhizophylls and induce the formation of several primordia
similar to nomophylls. The next step of this research will consist in the evaluation of the role of auxin in the
apical meristem development, and of the combined effect of auxin/cytokinin. Another objective of the
research is the study of the different secretory structures present in the rhizophyll, that are currently poorly
investigated. Microscopic analysis shown a spherical large body inside the glandular head of digestive
glands. The existence of these bodies has been reported only in one paper (2), however no hypothesis has
been formulated on its chemical nature and function. In the fresh sections, after 24-48 h, we observed a
gradual disappearance of the spherical bodies, that suggests a role in nutrient storage
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