Picea abies (L. ) Karst. is commonly cultivated in Italy for sale as Christmas trees. Experiments... more Picea abies (L. ) Karst. is commonly cultivated in Italy for sale as Christmas trees. Experiments were carried out to investigate the emergence and growth of three seed provenances of Picea to different levels of organic material. Mature seeds were collected from forests enrolled in the ”Libro Nazionale Boschi da Seme” (L.N.B.S.). Three certified seed provenances “Gran Bosco di Salbertrand”, “Pezzel e Fochino”, and “Val di Fiemme” were studied. The collected seeds were subjected to chilling treatment (4°C for 21 days), then were sown on benches in greenhouse. Two levels of organic material (manure) were used to achieve a total organic C content of 6.26% for substrate 1 and 9.82% for substrate 2. After 12 weeks, the seedlings were transferred in pots and placed in a shaded (50% light reduction) outdoors for one year. The seedling growth performance was significantly influenced by provenances and substrates (P<0.05). The interactions between substrate and provenance were evident 15...
The commercial micropropagation of olive trees is currently limited by the production cost. An ex... more The commercial micropropagation of olive trees is currently limited by the production cost. An ex vitro method for olive microshoot rooting could reduce both the production cost per plant and the propagation time. In this study a successful ex vitro rooting protocol tested on seven olive cultivars is reported. The explants of cv. Maurino were collected from fifth, sixth, and seventh proliferative subcultures carried out on MSM medium, while for the other cultivars the explants were collected from only seventh proliferative subculture. Continuous light during the rooting phase was a prerequisite for the success of the ex vitro protocol. The best source of microshoots for a high rooting percentage was the seventh proliferative subculture. Cvs. Coratina, Maremmano, Maurino, Picholine, and S. Francesco showed high rooting percentages with a range of 62–76%; whereas for cvs. Correggiolo and Frantoio the experimental conditions need to be optimised. Up to 90% of the rooted microplants sur...
ABSTRACT Zygotic embryos, stratified and collected at 8, 16 and 24 weeks and cotyledonary and epi... more ABSTRACT Zygotic embryos, stratified and collected at 8, 16 and 24 weeks and cotyledonary and epicotyl explants from 30 and 45 day old Cycas revoluta Thumb. seedlings were cultured in vitro to determine their morphogenic potential. Depending upon the duration of stratification and growth regulator type, zygotic embryos exhibited a different morphogenic response. The youngest embryos rarely survived, while larger ones formed a callus, depending on the growth regulator in the medium, and the oldest ones produced putative embryogenic masses. Cytokinin levels double the auxin concentrations resulted in shoot regeneration in almost mature embryos. In addition, in vitro culture of younger cotyledonary explants gave shoot regeneration, while older ones formed adventitious roots. The effectiveness of BA in inducing shoot regeneration from seedling explants was confirmed. NAA in combination with cytokinin in the induction medium inhibited bud induction. These results show that the morphogenic potential of tissues is linked to their developmental stage.
ABSTRACT The rate of microshoot proliferation during the micropropagation of olive (Olea europaea... more ABSTRACT The rate of microshoot proliferation during the micropropagation of olive (Olea europaea L.) plants is limited by the low rates of both bud sprouting and growth of secondary shoots following subculturing. The aim of this study was to determine (1) the effects of sucrose and mannitol on shoot growth, (2) whether either of these sugars modifies the pattern of shoot development of the explants, and (3) the influence of apical dominance on explant development. Working with single-node micro-cuttings of Olea europaea L. cv. Maurino with two opposite axillary buds, we added 17, 34, or 68 g L -1 of sucrose or mannitol to the medium as the primary carbon source. Shoot development was classified as either (a) an outgrowth of the first bud on an explant (shoot-type A), (b) an outgrowth of the second bud (shoot-type B), or (c) an outgrowth of an axillary bud on either an A-or B-type shoot (shoot-type C). Explant survival, fresh-mass pro-duction, and patterns of shoot development were influenced by the type and concentration of sugar used. Mannitol promoted the sprouting and growth of A-, B-, and C-type shoots more than sucrose. The developmental responses observed indicate that the growth of axillary meristems of in vitro olive explants is not regulated by apical domi-nance. The results demonstrate that the sugar alcohol plays an important role in the developmental regulation of olive explants. Mannitol may also protect against detrimental effects associated with in vitro growth conditions.
... detachment. The Petri dishes were closed with polythene film to prevent humidity loss during ... more ... detachment. The Petri dishes were closed with polythene film to prevent humidity loss during the experiment. Chlorophyll fluorescence measurements were carried out with a pulse-amplitude-modulation fluorometer (PAM 2000). The ...
The morphological fidelity of the olive plants propagated through axillary buds, microplants and ... more The morphological fidelity of the olive plants propagated through axillary buds, microplants and somatic embryogenesis, somatic plants was evaluated. Thirty-two morphological traits were used to characterize the tissue culture propagated olive plants. The microplants showed very high phenotypic similarity compared to plants produced by conventional cutting propagation method. The somatic plants exhibited variant morphological stable phenotypes, among somaclonal population two variant phenotypes were studied: BOS (bush-olive somaclone) and COS (columnar-olive somaclone). A wide range of plant traits were differently involved in somaclonal variation as plant height, canopy dimensions, leaf, inflorescence and fruit dimensions in respect to the putative control plants. The present study has established that the morphological stability of tissue culture-derived olive plants is strictly related with the in vitro propagation method used.
Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were ap... more Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were applied to assess the genetic stability of micropropagated olive (Olea europaea L. cv. Maurino) plants regenerated by axillary buds. Initial olive explants, isolated from one donor tree, were multiplied on Murashige and Skoog medium for 12 repeated subcultures. A total of 40 RAPD and 10 ISSR markers resulted in 301 distinct and reproducible band classes showing homogeneous RAPD and ISSR patterns. The amplification products revealed genetic stability among the micropropagated plants and between them and the donor plant. The results demonstrate the genetic stability of nine year old mature micropropagated olive plants cultured in field, and corroborated the fact that axillary multiplication is the safest mode for multiplication of true to type plants.
Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were ap... more Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were applied to assess the genetic stability of micropropagated olive (Olea europaea L. cv. Maurino) plants regenerated by axillary buds. Initial olive explants, isolated from one donor tree, were multiplied on Murashige and Skoog medium for 12 repeated subcultures. A total of 40 RAPD and 10 ISSR markers resulted in 301 distinct and reproducible band classes showing homogeneous RAPD and ISSR patterns. The amplification products revealed genetic stability among the micropropagated plants and between them and the donor plant. The results demonstrate the genetic stability of nine year old mature micropropagated olive plants cultured in field, and corroborated the fact that axillary multiplication is the safest mode for multiplication of true to type plants.
Picea abies (L. ) Karst. is commonly cultivated in Italy for sale as Christmas trees. Experiments... more Picea abies (L. ) Karst. is commonly cultivated in Italy for sale as Christmas trees. Experiments were carried out to investigate the emergence and growth of three seed provenances of Picea to different levels of organic material. Mature seeds were collected from forests enrolled in the ”Libro Nazionale Boschi da Seme” (L.N.B.S.). Three certified seed provenances “Gran Bosco di Salbertrand”, “Pezzel e Fochino”, and “Val di Fiemme” were studied. The collected seeds were subjected to chilling treatment (4°C for 21 days), then were sown on benches in greenhouse. Two levels of organic material (manure) were used to achieve a total organic C content of 6.26% for substrate 1 and 9.82% for substrate 2. After 12 weeks, the seedlings were transferred in pots and placed in a shaded (50% light reduction) outdoors for one year. The seedling growth performance was significantly influenced by provenances and substrates (P<0.05). The interactions between substrate and provenance were evident 15...
The commercial micropropagation of olive trees is currently limited by the production cost. An ex... more The commercial micropropagation of olive trees is currently limited by the production cost. An ex vitro method for olive microshoot rooting could reduce both the production cost per plant and the propagation time. In this study a successful ex vitro rooting protocol tested on seven olive cultivars is reported. The explants of cv. Maurino were collected from fifth, sixth, and seventh proliferative subcultures carried out on MSM medium, while for the other cultivars the explants were collected from only seventh proliferative subculture. Continuous light during the rooting phase was a prerequisite for the success of the ex vitro protocol. The best source of microshoots for a high rooting percentage was the seventh proliferative subculture. Cvs. Coratina, Maremmano, Maurino, Picholine, and S. Francesco showed high rooting percentages with a range of 62–76%; whereas for cvs. Correggiolo and Frantoio the experimental conditions need to be optimised. Up to 90% of the rooted microplants sur...
ABSTRACT Zygotic embryos, stratified and collected at 8, 16 and 24 weeks and cotyledonary and epi... more ABSTRACT Zygotic embryos, stratified and collected at 8, 16 and 24 weeks and cotyledonary and epicotyl explants from 30 and 45 day old Cycas revoluta Thumb. seedlings were cultured in vitro to determine their morphogenic potential. Depending upon the duration of stratification and growth regulator type, zygotic embryos exhibited a different morphogenic response. The youngest embryos rarely survived, while larger ones formed a callus, depending on the growth regulator in the medium, and the oldest ones produced putative embryogenic masses. Cytokinin levels double the auxin concentrations resulted in shoot regeneration in almost mature embryos. In addition, in vitro culture of younger cotyledonary explants gave shoot regeneration, while older ones formed adventitious roots. The effectiveness of BA in inducing shoot regeneration from seedling explants was confirmed. NAA in combination with cytokinin in the induction medium inhibited bud induction. These results show that the morphogenic potential of tissues is linked to their developmental stage.
ABSTRACT The rate of microshoot proliferation during the micropropagation of olive (Olea europaea... more ABSTRACT The rate of microshoot proliferation during the micropropagation of olive (Olea europaea L.) plants is limited by the low rates of both bud sprouting and growth of secondary shoots following subculturing. The aim of this study was to determine (1) the effects of sucrose and mannitol on shoot growth, (2) whether either of these sugars modifies the pattern of shoot development of the explants, and (3) the influence of apical dominance on explant development. Working with single-node micro-cuttings of Olea europaea L. cv. Maurino with two opposite axillary buds, we added 17, 34, or 68 g L -1 of sucrose or mannitol to the medium as the primary carbon source. Shoot development was classified as either (a) an outgrowth of the first bud on an explant (shoot-type A), (b) an outgrowth of the second bud (shoot-type B), or (c) an outgrowth of an axillary bud on either an A-or B-type shoot (shoot-type C). Explant survival, fresh-mass pro-duction, and patterns of shoot development were influenced by the type and concentration of sugar used. Mannitol promoted the sprouting and growth of A-, B-, and C-type shoots more than sucrose. The developmental responses observed indicate that the growth of axillary meristems of in vitro olive explants is not regulated by apical domi-nance. The results demonstrate that the sugar alcohol plays an important role in the developmental regulation of olive explants. Mannitol may also protect against detrimental effects associated with in vitro growth conditions.
... detachment. The Petri dishes were closed with polythene film to prevent humidity loss during ... more ... detachment. The Petri dishes were closed with polythene film to prevent humidity loss during the experiment. Chlorophyll fluorescence measurements were carried out with a pulse-amplitude-modulation fluorometer (PAM 2000). The ...
The morphological fidelity of the olive plants propagated through axillary buds, microplants and ... more The morphological fidelity of the olive plants propagated through axillary buds, microplants and somatic embryogenesis, somatic plants was evaluated. Thirty-two morphological traits were used to characterize the tissue culture propagated olive plants. The microplants showed very high phenotypic similarity compared to plants produced by conventional cutting propagation method. The somatic plants exhibited variant morphological stable phenotypes, among somaclonal population two variant phenotypes were studied: BOS (bush-olive somaclone) and COS (columnar-olive somaclone). A wide range of plant traits were differently involved in somaclonal variation as plant height, canopy dimensions, leaf, inflorescence and fruit dimensions in respect to the putative control plants. The present study has established that the morphological stability of tissue culture-derived olive plants is strictly related with the in vitro propagation method used.
Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were ap... more Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were applied to assess the genetic stability of micropropagated olive (Olea europaea L. cv. Maurino) plants regenerated by axillary buds. Initial olive explants, isolated from one donor tree, were multiplied on Murashige and Skoog medium for 12 repeated subcultures. A total of 40 RAPD and 10 ISSR markers resulted in 301 distinct and reproducible band classes showing homogeneous RAPD and ISSR patterns. The amplification products revealed genetic stability among the micropropagated plants and between them and the donor plant. The results demonstrate the genetic stability of nine year old mature micropropagated olive plants cultured in field, and corroborated the fact that axillary multiplication is the safest mode for multiplication of true to type plants.
Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were ap... more Randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were applied to assess the genetic stability of micropropagated olive (Olea europaea L. cv. Maurino) plants regenerated by axillary buds. Initial olive explants, isolated from one donor tree, were multiplied on Murashige and Skoog medium for 12 repeated subcultures. A total of 40 RAPD and 10 ISSR markers resulted in 301 distinct and reproducible band classes showing homogeneous RAPD and ISSR patterns. The amplification products revealed genetic stability among the micropropagated plants and between them and the donor plant. The results demonstrate the genetic stability of nine year old mature micropropagated olive plants cultured in field, and corroborated the fact that axillary multiplication is the safest mode for multiplication of true to type plants.
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