Due to the widespread polyembryony, Citrus rootstocks are usually propagated through openpollinated seeds, even if micropropagation offers many advantages. In vitro plant regeneration from epicotyl segments has been obtained in many Citrus genotypes. In this study, epicotyl segments (obtained from seeds of Carrizo citrange germinated in vitro) were used to evaluate the influence on in vitro organogenesis of explant orientation, of cut surface contact with the medium, of treatments with different growth regulators and of distance of organogenic explants from the cotyledonary node. The highest organogenic response was obtained from the basal portion of epicotyl horizontally cultured, from the segments longitudinally cut with the cut surface in contact and from explants cultured on medium added with 6-benzylaminopurine. No significant difference in regeneration efficiency was found in response to the distance of the epicotyl portions from the cotyledonary node. Uninodal microcuttings 3-4 mm long, excised from in vitro proliferating shoots were used for experiments on encapsulation, in which the influence of the calcium alginate coating, of the short time storage and of different sowing substrates on viability and regrowth of microcuttings were essayed. Furthermore, preliminary attempts to study an efficient protocol to induce root formation in the microcuttings were performed. The results showed no negative effect of the encapsulation on the microcuttings viability, a satisfactory regrowth and the possibility to store for 30 days at low temperature the encapsulated explants. Moreover, no differences in viability and regrowth were detected between two different sowing substrates.
Organogenesis and encapsulation of in vitro-derived propagules of Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirius trifoliata (L.) Raf].
MICHELI, Maurizio;STANDARDI, Alvaro
2011
Abstract
Due to the widespread polyembryony, Citrus rootstocks are usually propagated through openpollinated seeds, even if micropropagation offers many advantages. In vitro plant regeneration from epicotyl segments has been obtained in many Citrus genotypes. In this study, epicotyl segments (obtained from seeds of Carrizo citrange germinated in vitro) were used to evaluate the influence on in vitro organogenesis of explant orientation, of cut surface contact with the medium, of treatments with different growth regulators and of distance of organogenic explants from the cotyledonary node. The highest organogenic response was obtained from the basal portion of epicotyl horizontally cultured, from the segments longitudinally cut with the cut surface in contact and from explants cultured on medium added with 6-benzylaminopurine. No significant difference in regeneration efficiency was found in response to the distance of the epicotyl portions from the cotyledonary node. Uninodal microcuttings 3-4 mm long, excised from in vitro proliferating shoots were used for experiments on encapsulation, in which the influence of the calcium alginate coating, of the short time storage and of different sowing substrates on viability and regrowth of microcuttings were essayed. Furthermore, preliminary attempts to study an efficient protocol to induce root formation in the microcuttings were performed. The results showed no negative effect of the encapsulation on the microcuttings viability, a satisfactory regrowth and the possibility to store for 30 days at low temperature the encapsulated explants. Moreover, no differences in viability and regrowth were detected between two different sowing substrates.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
