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Bananas and plantains are grown in tropical and subtropical regions of the world. These plants required high humid conditions; therefore water deficit affects their growth and productivity. Through biotechnology, new drought tolerant genotypes could be obtained. These genotypes can be selected from in vitro culture by adding osmo-stressor agents to the media. The aim of this work was to determine the response of in vitro banana plants cv. 'Grande naine' (Musa AAA) to water stress induced by polyethylene glycol. Morphological (height and number of shoots per explant), physiological (total chlorophyll and relative water chlorophyll contents) and biochemical (proline, malondialdehyde and hydrogen peroxide contents) traits of water stress were determined on stressed and unstressed plants. On stressed plants, a decrease in height and number of shoots per explant, and the increase in proline and malondialdehyde contents were observed. However, total chlorophyll, hydrogen peroxide and relative water contents were not affected. These findings showed that polyethylene glycol can be used as osmo-stress inducer for in vitro selection of drought tolerant banana plants. [ABSTRACT FROM AUTHOR]

Somatic embryogenesis (SE) has been developed in several species of plants with different objectives. Even though, the mass production of plants and the evaluation of field behaviour in big populations been achieved in few cases. Somatic embryogenesis has been developed in some cultivars of Musa spp. to facilitate protocols of genetic transformation. Though, this technique can be an alternative to increase the efficiency for mass production of in vitro plants to commercially scale for cultivation in productive areas. The aim of this paper was to determine the field behaviour of dwarf Cavendish plants obtained by somatic embryogenesis. The evaluations were carried out about the stability of the some morphological and quantitative characters of the plants related to the yield components were evaluated. The agricultural yield, under production conditions, of this plants compared to plants derived from suckers, conventionally cultured, was also determined. Results indicated that plants obtained by SE presented very few indexes of morphological variation in both productive cycles. The agricultural yield was superior with regard to the plants obtained by suckers in both cycles. Results of a population evaluated of more than 5 000 plants, obtained by SE in the cultivar 'Dwarf Cavendish', constituted a reliable evidence to recommend this method as a viable alternative for the in vitro mass propagation of plants in this cultivar. [ABSTRACT FROM AUTHOR]

The season of the year is one of the possible factors to consider for taking the initial explants to develop somatic embryogenesis. This work was carried out to determine the influence of the season of the year on the callus with embryogenic structures formation, in the banana cultivar 'Grande naine' (Musa AAA) to collect immature male inflorescences are. Male inflorescences were collected for three years, every month. Nodal fascicles closest to the floral meristem were extracted and placed in semisolid medium. The number of contaminated explants and the embryogenic response for each time was quantified, six months after culture. The percentage of microbial contamination and the percentage of fascicles that formed callus with high frequency somatic embryogenesis were calculated using these data. In addition, it the relationship of these variables with the values of average temperatures and precipitations during the three years were also studied. The percentages of contamination were highly variable depending on the season of the year in which the inflorescences were collected in the field (0 - 82.5%). The analysis did not show correlation between embryogenic response and percentage of contamination, in relation to rainfall and temperature values recorded during the three years of research. Embryogenic response ranged from 0-11.5%. Results showed that the season of the year to collect immature male inflorescences did not influence the formation of somatic embryos in this cultivar of banana. [ABSTRACT FROM AUTHOR]

The present work was carried out with the objective to obtain plantain transgenic plants of 'Navolean' (Musa AAB) cultivar and to evaluate them, under field conditions during the first crop cycle, for Black Sigatoka disease. Embryogenic cell suspensions obtained from scalp were used for the transformation by Agrobacterium tumefaciens. The bacterial strain EHA-105 was used with the binary plasmid pHGA-91, which contained a combination of genes that encode for the antifungal glucanase enzyme and the AP24 osmotin. Twenty putative transformed lines of the construct were obtained after two months of selection in the culture medium. The transgenic events were verified by means of PCR and Southern hybridisation. These confirmed the stable integration and expression of the transgenes in transgenic plants that were selected in field showing differences with non-transgenic plants used as control. [ABSTRACT FROM AUTHOR]

The study aimed to develop somatic embryo (Es) formation of cv. 'FHIA-21' (Musa AAAB) in a liquid culture medium, based on embryogenic cell suspensions. Four inoculation densities (0.5, 1.0, 1.5 and 2.0g of fresh mass (GMF) of embryogenic cell aggregates) in 250 ml Erlenmeyer capacity, which contained 30 ml of culture medium, were studied. Evaluations were made within 30 days of culture. The following variables were identified: number of Es, length (mm), and morphological and histological features. Results showed the regulatory effect of inoculation density on the formation and morphological development of Es. In this sense, the low density (0.5 and 1.0 GMF) brought about a lower amount of ES, which was larger and with more advanced ontogenetic development. However, the high density of inoculation (1.5 and 2.0 GMF) produced a larger number of uniform size Es and in the globular stage. [ABSTRACT FROM AUTHOR]

The adjustment of an efficient protocol of somatic embryogenesis in Stevia rebaudiana Bertoni to support programs of genetic breeding by genetic transformation is necessary. Few results are registered up to the moment in this species. The objective of this work was to obtain calli with embryogenic structures from clones of Stevia in vitro plants. Different variables were studied for the formation of calli: explants type, incubation conditions and genotype influences. Culture medium MS with different growth regulators (2,4-D; 6-BAP; TDZ) was used. These were used alone or in combination. Calli were multiplied in the best culture media. Afterwards they were subcultured to culture medium containing 2,4-D or TDZ with 40 and 60 g·l-1 of sucrose to induce proembryogenic mass formation. Calli formation was achieved after 45 days of culture in darkness and in culture media with 2.26 μM 2,4-D and 2.22 μM 6-BAP or 1.13 μM 2,4-D and 0.45 μM of TDZ. Foliar explants of in vitro plants of Stevia were used. Multiplication was achieved in the same culture media for calli formation. The largest amount of calli with development of proembryogenic mass was obtained when subcultures to culture medium with 0.45 μM 2,4-D adding 40 g·l-1 of sucrose was carried out after 45-50 days of culture. [ABSTRACT FROM AUTHOR]

The most important papaya variety in Cuba is Red Maradol. However, it is susceptible to the main viral diseases that attack this crop. For this reason, it is necessary to establish a method for plant regeneration via somatic embryogenesis as the base to develop a protocol for genetic transformation to obtain resistant plants. The objective of this work was to obtain somatic embryos of papaya Red Maradol starting from zygotic embryos. The effect of different factors in somatic embryogenesis and plant regeneration, starting from immature zygotic embryos, was evaluated. The somatic embryos were obtained in a culture medium MS with 5 mg.l-1 2,4-D. Also, the use of 2 mg.l-1 of this plant growth regulator had a positive effect in the secondary multiplication of somatic embryos. The addition of 5 mg.l-1 AIB favored the buds rooting (78.0%), but its longitude was inferior to 1.85 cm. The culture of buds in liquid elongation medium allowed them to reach an average longitude of 3.05 cm and 4.50 leaves, which permitted its appropriate survival in the acclimatization phase. [ABSTRACT FROM AUTHOR]

Comparison of two methods for the establishment of embryogenic cell suspensions obtained from the culture of male flower directly in liquid culture medium and embryogenic callus of banana cv. 'Grande naine' (Musa AAA) was studied in this work. Establishment of homogeneous embriogenic cell suspensions from the culture of both explants in liquid medium was achieved though floral bud range eight showed the best results. Differences in the growing of cell suspension, somatic embryos formation and germination was not observed when the suspensions were compared. Nevertheless the methodology proposed in this work was faster than the 'callus' methodology and percentage of establishment was higher. [ABSTRACT FROM AUTHOR]

The need of producing high quality planting material has required the searching of new alternatives to increase the efficiency of in vitro propagation methods and their automation, such as Temporary Immersion Systems. This work has been carried out to increase the multiplication coefficient in mass propagation of hybrid 'FHIA-21' (AAAB) in Temporary Immersion Systems. Different culture medium volumes per explant and densities of planting materials per unit were studied at the same immersion frequency. The highest multiplication coefficient rate, (14.99 and 16.02 respectively), was obtained when 40 ml culture medium volume were used at a density of 70 explants/flask. The use of Temporary Immersion System allowed increasing the multiplication coefficient in hybrid 'FHIA-21' (AAAB) and the highest quality multiplication coefficient for rooting stage and further acclimatization in field conditions. [ABSTRACT FROM AUTHOR]

The present work had the objective of determining the minimum lethal doses of the selective agent phosphineotricine, to establish the adequate conditions for the selection of genetically transformed cellular embryogenic aggregates of banana cultivar Grande Naine. Schenk and Hildebrandt culture medium, modified by Bieberach, was used , adding different concentrations of the selective agent at (0, 3, 6, 9 and 12 mg ·l-1). The evaluation of the survival of the explants was carried out visually to the 30 days of culture using the scale elaborated in this work, as well as the cellular vitality for staining with Diacetate of Fluoresceine (DAF). The concentrations of the selective agent used, were the cause of the plant cells death. This effect was increased when increasing the concentration and the time of exposition from the vegetable material to the culture medium with the selective agent (increase of the toxicity). The minimal lethal doses selected was 6 mg·l-1 because the total necrosis in the banana cells and death of the tissue produced when was observed to the microscope the vitality of the cellular aggregates. [ABSTRACT FROM AUTHOR]

This investigation had as objective to obtain plants of plantain hybrid cultivar 'FHIA-21' (Musa AAAB) from embryogenic cell lines. For this study cell lines of callus were established with embryogenic structures formed of immature male flowers. The results showed differences among the lines during the phase of multiplication of the embryogenic cell suspension. The same ones were showed in the cellular growth. The vitality of the embryogenic cluster cells oscillated between 99.7 and 100% without statistic differences among the studied lines. The influence of the cell line was observed in the germination of the somatic embryos, the cell line number two presented the biggest number of germinated embryos. When concluding the experiments a total of 8 230 plants of the studied cell lines were obtained. These cell lines adapted to ex vitro conditions at greenhouse with high percentages of survival and some phenotypic changes were observed in less than 1.0% of the total of plants. The necessity of keeping in mind the factor cell line for the obtaining of plants of cultivar hybrid 'FHIA 21' by somatic embryogenesis was proven. [ABSTRACT FROM AUTHOR]

The somatic embryogenesis propagation technique and tool for the genetic improvement in sugar cane (Saccharum spp. hybrid) has presented multiple inconveniences that the regeneration protocols described in the literature have not been able to solve. The present research was carried out with the objective of developing a new methodology for the establishment of cell suspensions of sugar cane, var. C 87-51, through somatic embryogenesis based on segments of the sheath of the leaves of in vitro plants, placed directly in a liquid culture medium. The results demonstrated that it is possible to form callus with embryogenic structures based on segment two of the sheath of the leaves which reduces the time of culture in vitro and guarantees the physiologic and phytosanitary quality of the plants that are regenerated. Homogeneous lines of cellular suspensions formed by embryogenic aggregates were established based on callus with embryogenic structures. [ABSTRACT FROM AUTHOR]

This work was carried out at the Plant Biotechnology Laboratory from the Instituto de Investigaciones en Viandas Tropicales (INIVIT) in order to determine the culture medium for the multiplication of hybrid 'FHIA-21' (AAAB) in Temporary Immersion Systems. Different combinations of growth regulators and growth inhibitors (6-BAP, IAA and PBZ) were studied. Results permitted to determinate the effect of 6-benzil-amino-purine (6-BAP), Indol Acetic Acid (AIA) and Paclobutrazol (PBZ) for multiplication of hybrid 'FHIA-21' (AAAB) in the Temporary Immersion System, which involved supplemented MS salts with 2.0 mg.l-1 6-BAP; 0.65 mg.l-1 IAA and 10.0 mg.l-1 ascorbic acid; as well as, 1.0 mg.l-1 paclobutrazol. A decrease of unnecessary growing of shoots and leaves from sprouts in the multiplication phase and a greater sprout number per inoculated explant without multibuds and hyperhydricity were achieved. The Temporary Immersion System allowed to increase the number of axillary sprouts by micropropagation of hybrid 'FHIA-21' (AAAB) and a higher quality of in vitro plants. [ABSTRACT FROM AUTHOR]

The establishment of conditions of culture is essential to regulate of efficient way the regeneration of plantain plants cv. 'FHIA-21' by somatic embryogenesis. It is for that reason that this investigation had like objective to determine the effect of the density of inoculation on maturation of somatic embryos. For the study were added 0.2, 0.4 and 0.6 grams of somatic embryos on 60 ml of culture means maturation semisolid. The evaluations were realized to the 30 days of culture with the analysis of the morphologic characteristics of the embryos, the determination of the fresh mass (g) and presence of embryos with exhibition of apical shoot. Later, the number of germinated embryos was determined and a morphologic characterization of its germination was realized. The results showed the influence of the density of inoculation in the increase of the fresh mass and in the presence of embryos with exhibition of apical shoot. Nevertheless, significant differences with respect to the total of germinated embryos did not appear, the values oscillated between 8.4 and 11.2 by bottle of culture. In spite of it, one better germination was evident when the 0.4 embryos were worked to gMF, during the phase of maturation. From the embryos with complete and partial germination plants were developed to the 25 and 35 days of culture, respectively, during the phase of growth. These plants were characterized to have a height between 3.5 and 4.0cm, more than three open leaves and a system to radical developed. Aspects that favoured a high survival during the phase of acclimatization in green house. [ABSTRACT FROM AUTHOR]

In Cuba, the Xanthosoma genus is highly demanded in the preference of the population in relation to other edible aroids. The temporary immersion system (TIS) may constitute a micropropagation alternative to obtain high quality seed in this crop. The effect of two Semi-automated Culture Systems (SIT) and Constant Immersion Systems (CIS) with aeration through continuous bubbling in culture medium during the multiplication stage of axillaries shoot buds was evaluated. Results allowed demonstrating superiority in the efficiency of SIT regarding CIS in the sprout multiplication of clone 'Viequera'. Axillaries sprout buds cultivated in TIS showed the best results in the multiplication compared with CIS and the static culture system with passive renewal of the internal atmosphere was used as control. The culture conditions created in the temporary immersion system for in vitro multiplication of axillaries sprout buds achieved the highest multiplication coefficient (9.56). This in vitro culture system will allow increasing the multiplication coefficients in the micropropagation for seed production in this genus. [ABSTRACT FROM AUTHOR]

The acclimatization stage of in vitro cultured papaya (Carica papaya L.) remains one of the main problems. This study evaluated the influence of the type of cover and length of in vitro plants on their survival in the acclimatization phase. Plants of papaya, variety red Maradol, obtained by somatic embryogenesis were used. An 80% survival rate was reached using a nylon and mesh cover. Results demonstrated that in vitro plants should be transferred to greenhouse conditions larger than 3 cm and with taproot present. This is a decisive influence on the development of plants in ex vitro conditions. [ABSTRACT FROM AUTHOR]

Somatic embryogenesis in papaya has been subjected to much research. However, the effect of ex vitro and in vitro environments on this process has been little studied. The objectives of this work were to determine the influence of the seasons for fruit harvest on the formation of papaya somatic embryo stage, based on zygotic embryos of immature fruits and the effect of the kind of culture flask on the formation and germination of somatic embryo stages. Results demonstrated that the season for the collection of immature fruits did not influence the formation of somatic embryos. Besides the use of glass culture flasks allowed to obtain 63.7% of embryos that developed zygotic embryos. The best results were achieved using this kind of culture flask, with a 90.7% germination of somatic embryos. [ABSTRACT FROM AUTHOR]

The present work was carried out to evaluate genetic stability in plants obtained by somatic embryogenesis of cv. hybrid 'FHIA 21' (Musa AAAB) in the field. A number of 6 252 plants were planted and 2 000 plants obtained by organogenesis and same quantity coming from asexual seeds were used as control for this study. The plantation density was 3 333 plants per hectare, at a distance of 3×2×1.20m each one. Four repetitions were carried out in a Latin Square experimental design. Evaluations were made during the first plantation cycle through out morphological and agronomic characters of more contribution to detection of genetic variability. Results showed high genetic stability in plants obtained by somatic embryogenesis of cv. hybrid 'FHIA 21' (Musa AAAB), given by the low percentage of somaclonal variation (0.015%). Besides, the evaluation of the agronomic characters (bunch weigh, number of hands/bunch and number of fruits/hands) did not present statistical differences among the plants coming from the in vitro culture (somatic embryogenesis and organogenesis), but some differences were observed when compared to plants from asexual seeds. Results of this work validate somatic embryogenesis for the massive propagation of cv. hybrid of banana 'FHIA-21.' [ABSTRACT FROM AUTHOR]

The AFLP technique is based on the selective amplification of restriction fragment by polymerase chain reaction (PCR) and consists of four basic steps; digestion with restriction enzymes of deoxyribonucleic acid (DNA), adapter ligation with fragments of DNA and amplification of the fragments obtained in the earlier steps using combinations of selective primers and detection of polymorphism using radioisotopes, fluorescent dyes or silver staining. It is widely used in the evaluation of genetic diversity, analysis of genetic distance, DNA fingerprint, germoplasm collections analysis, genetic maps construction and markers diagnostic monitoring. In order to characterize molecularly two species of crops with agricultural interests (sugar cane and banana) were generated AFLP markers. In this study was demonstrated the ability to identify variations in the genome of crops studied. [ABSTRACT FROM AUTHOR]

Pinus taeda L. is a forest species of great international importance and in Argentina. Biotechnological techniques can provide an alternative to propagate this species, as well as for obtaining mother plants. The aim of this study was to achieve adequate elongation of in vitro shoots before transfer to the rooting stage. The shoots were obtained from acclimatized mother plants. It was disinfected for in vitro establishment. Two types of basal culture media: WV5 and DCR were studied. The best results were achieved with the combination of the WV5 salts supplement with 0.5% activated carbon, 0.01 mg l-1 ANA to obtain vigorous and longer than 40.0 mm in length shoots. [ABSTRACT FROM AUTHOR]

The somatic embryogenesis response is close linked with the development phase of the explant donor plant. Therefore, the objective of this work was to determine the effect of male flower position in the plant on the embryogenic responses in plantain cv. 'FHIA-21' (Musa AAAB). In this study male flower were collected at 0, 10, 20 and 30 cm from the last female flower. After 20 weeks on culture, the number of callus with somatic structures was evaluated. Thereafter, the effect of the callus morphology in the establishment of embryogenic cell suspensions was assessed. The results showed that the development phase of immature male flower (measured by the distance to the last female flower) was an important factor on the embryogenic callus induction. The best response on embryogenic callus formation (8.77%) was obtained with explants collected just after the last female flower (0 cm). Although, it was possible to assess that 85.0% of the callus composed by pro-embryogenic masses and somatic embryos in the early stage of its ontogeny development, resulted in embryogenic cell suspensions with the major volume of settled cell aggregated. As a result, it was possible to conclude that the age of the male flower play an important role on the somatic embryogenic process in plantain cv. 'FHIA-21'. [ABSTRACT FROM AUTHOR]

Rational use of multivariate statistics, modeling and biological knowledge can help the researcher to design a tested crucial experiment and to reach consistent conclusions. This work is based on this statement and on a previous report of in vitro conservation of D. alata. It aims to apply some multivariate statistical techniques to determine the main factors which contribute to differentiating and grouping the treatments. The most suitable factors for the preservation of genetic resources of this species were also defined. The D. alata conservation process was evaluated by principal component analysis at 9 months. Percentage of survival, phenolization, explants with leaves, rooting, sprouting and leaf senescence, stem length, root number and number of novo nodes per explants were the analyzed variables. Results showed that the survival rate variables, percentage of explants with leaves, stem length, number of novo nodes and number of roots express much of the observed variation in the processes of growth and development. On the other hand, deterioration and aging of in vitro nodal segments buds is better explained by the percentage of phenolization variables and leaf senescence. The best treatments for in vitro conservation of D. alata based on variables with higher contribution in the multivariate statistical analysis, corresponded to the culture medium D - 571 with the 1.5% mannitol, 0.1 or 1 mg·l-1 BA and 2 g·l-1 of activated charcoal. [ABSTRACT FROM AUTHOR]

The disease caused by Papaya ringspot virus is the most important in papaya worldwide. The use of biotechnological techniques, as auxiliary tools, has facilitated genetic improvement in papaya. Nevertheless, this species has a lot of constraints, mainly during rooting and acclimatization phases. For that reason we developed the present work. The in vitro and ex vitro rooting was evaluated. Culture media with different concentrations of indol-3-butiric acid hormone were used in the in vitro rooting. The influence of Trichoderma harzianum bioproduct in the acclimatization of plants was also studied. The in vitro rooting of transgenic plants was achieved by applying 2 mg·l-1 of indol-3-butiric acid in the culture medium. The ex vitro rooting with high percentages of plants survival was also obtained. The applications of T. harzianum bioproduct on the substrate, previous to the plantation, demonstrated its stimulating effect. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to report, for first time, the presence of Ochrobactrum anthropi as contaminant of in vitro cell and tissue culture of sugarcane. Bacteria contaminant of in vitro plants were isolated directly from visibly contaminated plant culture on Tryptone soy agar medium and some drops of sugarcane cell suspension contaminated were inoculated on tubes with 3ml of Tryptone Soy Broth (TSB). Isolated bacteria were examined microscopically (shape, motility) and some biochemical test (Gram's stain (Hucker's modification), oxidase, catalase, O/F (oxidation/fermentation), were performed. Additional tests, according to Bergey's Manual of Determinative Bacteriology, were performed. Identification was complemented by fatty acid analysis. Different bacteria can be contaminating plant cell and tissue culture. However, references about the presence of Ochrobactrum anthropi as contaminant of in vitro culture of plant cell and tissue have not been reached. to control microbial contaminants, it is necessary to identify them. [ABSTRACT FROM AUTHOR]