1,721,108 research outputs found
Prospettive: "l'ortofrutticoltura di domani"
No full textIl contributo fornisce le principali linee di indirizzo per interpretare le nuove sfide che il comparto ortofrutticolo dovrà affrontare nel futur
L'ortofrutticoltura oggi
No full textIl lavoro affronta le principali tematiche connese al comparto esaminato mettendone in evidenze le innovazioni tecnoclogiche introdotte, nonché i caratteri economico-commercial
Le colture orticole
No full textIl contributo analizza gli aspetti tecnici produttivi, nonché quelli economico commerciali delle principali specie orticol
The effects of (S)-(+)-carvone treatments on seed potato tuber dormancy and sprouting
Full text linkPotato seed tubers may suffer from premature sprouting during storage, thus limiting their suitability for cultivation. Commonly used sprout suppressant treatments negatively affect bud viability and therefore a reliable method to inhibit bud development must still be found for seed tubers. The monoterpene carvone ((S)-(+)-carvone) was tested in small scale experiments. The vapour of this compound fully inhibited bud growth of tubers cv. Monalisa stored at 23 degrees C without affecting bud viability throughout 6 months of treatment. The most effective range of carvone vapour concentrations was between 0.34 and 1.06 mu mol mol(-1). With these qualities we can expect carvene to become a suitable sprout suppressant for seed tubers
Effects of gamma-ray treatment on Cannabis sativa pollen viability
No full textThe viability and the in vitro germination capability of hemp pollen (cv. Carmagnola) were studied. Viability tests
were based on the microscopic observation of the fluorescence of loaded fluorescein diacetate (FDA), while, for
germinability tests, five different media were tested. The effects of irradiation with 7-rays on pollen viability and
germination and on seed set were also studied, at three different irradiation doses (20, 60 and 100 krad). The results
show that in one of the media tested, about 85-90% of the pollen grains are viable and able to germinate in control
samples, and that while viability measured by FDA test is not affected by increased 7-ray doses, the pollen in vitro
germinability drops to about one-half of the controls at the maximum "y-ray dose employed, 100 krad. Seed set of
hemp plants pollinated with the irradiated pollen dropped to less than 1% of that of plants pollinated by untreated
pollen for the higher dose used. The different media suitable for in vitro germination of hemp pollen, and the
observed lack of correspondence between viability and germination capacity tests are discussed
Economia e mercato
No full textIl capitolo esamina i costi di produzione delle principali specie ortofrutticole, le tecniche di marketing a servizio delle produzioni ortofrutticole, le diverse organizzazioni di fliera e le evoluzioni dei mercati, sia nazionali, sia internazional
Meccanismi ormonali di controllo della dormienza del tubero di patata
No full textBioinvestigations on the mechanisms which control potato tuber dormancy are of basic importance, for both fresh market or processing products and seed tubers. Despite many years of research, the physiology of dormancy is not yet clear. Some recent results, achieved by several experimental approaches, represent a significant progress. Some hormonal classes are involved in this phenomenon, but current literature is often contradictory, therefore the role of these molecules must be studied in depth. Our research focused on auxins, a group of natural plant growth regulators which includes indoleacetic acid, the most studied and widespread auxin in higher plants, and the subject of our work. Changes of hormonal concentration in different tuber parts were analyzed by physic o -chemical techniques throughout dormancy and early sprouting. Further investigations by immunohystochemical techniques led to tissue-localization of indoleacetic acid during the above said experimental period. Early results from tubers of cv "Monalisa", from which all buds were excised and analyzed, suggested that auxin could induce bud outgrowth, because its concentration in buds rose during dormancy and early sprouting. Further and more accurate analyses were then planned, to be carried out on tubers from two different cultivars ("Agata" and "Merit", which markedly differ for dormancy length). In this work, only buds from the apical part of the tuber were sampled: these sprout earlier, therefore we assume that they undergo the most relevant physiological changes during the time of our experiments. Results from the latter work are in striking contrast with the previous ones, because indoleacetic acid concentration decreases in the apical buds of tubers of both cultivars, throughout dormancy and early sprouting. Immunostaining of indoleacetic acid confirms that the hormone is far more abundant in dormant than in sprouting buds: the apical meristem and the underlying, differentiating, vascular tissues of dormant buds show high levels of indoleacetic acid. The research dealing with "Agata" and "Merit" tubers yielded accurate and detailed results, which allowed us to put forward the following hypothesis on the role of indoleacetic acid in tuber dormancy control: the hormone would play a positive role on dormancy overcoming, by enhancing cell division and expansion in the bud apical meristem and differentiation of vascular tissues. In this way, auxin would cause a progressive increase of bud tissue mass and enhance the flow of nutrients and growth factors to the bud. Dormancy length undoubtedly depends on several endogenous signals, but indoleacetic acid is a key factor in the control of this phenomenon
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