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C. Benelli S. Grassi M. Lambardi E. Rugini 《The Journal of Horticultural Science and Biotechnology》2013,88(1):112-119
SummaryThis anatomical investigation on olive secondary somatic embryos describes several aspects of embryo development, including proembryoid origin and growth, aspects of tissue differentiation, localization of somatic embryogensis, and starch occurrence. The failure of a number of secondary somatic embryos to develop into perfect structures is to be ascribed to defects in the last growth stages (fused embryos, fused cotyledons) and/or to tissue degeneration processes affecting both imperfect and apparently perfect somatic embryos. 相似文献
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A highly efficient method of shoot regeneration was developed from calluses of four culti- vars of strawberries (Fragaria x ananassa Duch.), ‘Addie’, ‘Dana’, ‘Gea’ and ‘Santana’, grown in vitro. Optimum shoot regeneration (84-96% of the explants), with four to eight shoots was obtained from calluses developed from stipules near the internal zone between petiole and stipule, on Murashige and Skoog (1962) or Gamborg et al. (1968) media, supplemented with 3% (w/v) glucose, 10 [iM BAP and 2.5 IBA and 0.8% agar. The calluses continued to produce shoots for at least six subsequent subcultures. This has been reported, up to now, only in juvenile explants. Microscopic observation showed no preformed buds or meristematic groups of cells in the connecting zone of petiole and stipule prior to culture. However, there were several layers of cells in this area containing higher amounts of starch, which were not observed in the cells of the bottom or in the external side of the stipule. Regeneration from stipules occurred five to six days earlier in whole leaves (stipule + petiole + lamina) than in leaves without laminae, but the final percentage was the same in the cases of all explants. The percentage of regenerating calli from the other explant sources (leaf lamina, petiole and root) was low and dependent on cultivar. Cv. Gea, which showed the highest regeneration capacity, regenerated 32% from leaf laminae, 16% from petiole and root calluses, followed by cv. Addie with 12% from leaf laminae only; the others failed to regenerate from calluses derived from these tissues. The regenerated shoots were successfully rooted and hardened for further observations on eventual somaclonal variation. 相似文献
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This paper reports a procedure for isolating triploid and tetraploid olive plants, which have not been produced before either artificially or in nature. These polyploids were isolated from two mixoploid somatic mutants obtained earlier by treating Trantoio' and ‘Leccino’ plantlets with gamma radiation. The mixoploid mutants exhibit increased thickness of leaf, stem and root tissues, short internodes, a modified leaf lamina shape and a strong resistance to Spilocaea oleagina (Cast.) Hugh. In addition, they produce a mixture of normal drupes and some abnormally large ones, almost twice normal size. The variation in the nuclear DNA content of the mixoploid mutants is closely correlated with variation in their pollen size, crop capacity and the production of large fruit. Triploid genotypes with 69 chromosomes were isolated by germinating the seeds of these large fruits, collected from both the mixoploid mutants. Tetraploid plantlets, with 92 chromosomes, were obtained from cv. ‘Frantoio’ by selecting in vitro, during several proliferation phases, the shoots with obvate leaf shape which occurred among the shoots with normal lanceolate or intermediate leaf shape. 相似文献
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The effects of collection time, cutting age, indole-3-butyric acid (IBA) and putrescine application on the rooting of cuttings of Italian hazelnut cultivars ‘Tonda Gentile Romana’, ‘Tonda di Giffoni’ and ‘Nocchione’ were investigated. Samples collected during late June, late July and early September from newly formed and 1-year old part of twigs to be utilized to produce leafy cuttings, after being treated with 1000 and 2000 ppm IBA, respectively. In addition, the September cuttings were also treated, respectively, with 1000 and 2000 ppm IBA and 1600 ppm putrescine. Rooting ability was evaluated 2 months after planting for each treatment and collection time. Satisfactory rooting of hazelnut leafy cuttings was observed when collection time occurred in June and September, whereas leafy cuttings collected in July showed a limited capacity of rooting in all cultivars tested. On average, the rooting of the newly formed leafy cuttings was more than the 1-year old cuttings. Rooting was also promoted by IBA treatments, mainly in ‘Nocchione’ and ‘Tonda di Giffoni’. In contrast, young cuttings collected from ‘Tonda Gentile Romana’ in early September rooted poorly when treated with IBA alone, but showed the best rooting (∼80%) after the application of a combination of 1000 ppm IBA and 1600 ppm putrescine. The current findings confirm that putrescine can be a useful substance for increasing rooting percentage and root quality in cuttings of some hazelnut cultivars as obtained from ‘Tonda Gentile Romana’ cultivar. 相似文献
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Multiple shoots of high quality were produced in vitro from nodal expiants of Tectona grandis. An average of about 4 shoots/uninodal expiant was obtained within 4 weeks of culture on Murashige and Skoog’s (mMS) medium modified by 50% reduction in NH4NO3 concentration, supplemented with benzylaminopurine (1.5 mg L?1); indole-3-butyric acid (0.01 mg L?1) and gibberellic acid (0.1 mg L?1). The latter was applied both in the medium and by soaking the nodal segments for 10 s. in a gibberellic acid solution of 100 mg L?1. Hundred percent of shoots rooted cultured on modified MS medium containing IBA (0.5 mg L?1) and putrescine (160 mg L?1). Putrescine promoted both strong and highly ramified roots and fast growing shoots during the rooting phase, conditioning the plantlets for a good survival and quality. Plantlets were transferred to jiffy pots for a short acclimatization stage in greenhouse where they survived at 100%. This highly reproducible procedure can be adopted for large scale teak propagation. 相似文献
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E. Rugini 《Scientia Horticulturae》1984,24(2):123-134
Short- and long-term objectives for research on tissue culture of the olive are described. Sterile shoots were obtained from single-node woody explants or buds of 3 olive cultivars (‘Frantoio’, ‘Dolce Agogia’ and ‘Moraiolo’) with different root-ability, collected from shoots having different degrees of juvenility (suckers, vigorous nonfruit-bearing and fruit-bearing shoots, which are easy, medium and difficult to root, respectively).Because many of the media tested did not give a satisfactory growth rate and good quality shoots, a new medium was formulated by comparing data from analysis of the main mineral elements found in the apical shoots (4–5 mm long) and in mature embryos in olive and almond. Olive tissues were characterized by a high content of Ca, Mg, S, Cu and Zn compared to almond, which is easy to propagate on MS medium. In this newly derived medium, characterized by a high content of these elements, multiplication rate (number of nodes formed per explant) was about 9× in 40 days. The shoots grew more rapidly and were more tender than when grown in other media. Washing of the explants in water or GSH (reduced glutathione) solution, before sub-culturing, improved quality and growth rate of the shoots.Explants, with 2 or 3 nodes, rooted easily in half-strength MS, in Bourgin and Nitsch, or in half Knop macro and Heller microelements, agar media, with 1 mg 1?1 NAA and 2% sucrose. Rooting was not affected by the different degrees of juvenility of the original explants used.Hardening-off was achieved by growing plants in a 1:1 mixture of perlite and peat-moss in a transparent plastic chamber with saturated circulating air for 1 month. GA3 sprayed on the leaves was found to be beneficial in stimulating growth resumption of plantlets. 相似文献
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