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- Author or Editor: Gerson R. de L. Fortes x
The aim of this work was to study different apple of somatic material as callus and adventitious shoots are concerned, for further utilization in the research of somaclonal variation. The somatic materials were: leaf discs, cotyledons and hypocotyls of Gala apple seedlings, cultivated in a MS medium added by B5 vitamins in addition to (in mg/l): BAP (1,0), NAA (0,5) mio-inositol (100,0) sucrose (30,0 g/l) and solidified in agar (6,0 g/l). The several times of explant exposition to the dark affected the final callus weight. Callus weight derived from leaf discs were higher than those for cotyledons and hypocotyls. Explants exposed directly under light or up to two weeks in the dark showed less percentage of regenerative callus as compared to those of three weeks in the dark. The leaf explants presented the highest percentage of regenerative callus. The least response was obtained for those derived from hypocotyls. The highest number of adventitious shoots was obtained keeping the explants three weeks in the dark as compared to directed light exposition.
The present work aimed to evaluate the plant growth of the apple rootstock Marubakaido during the acclimatization process, after receiving different treatments of temperatures. Apple shoots were rooted in vitro and transplanted to greenhouse, where they remained for 2 weeks. After this period, the plants were treated under temperature of 4 ± 1 °C and 10 ± 1 °C, 16-h photoperiod at 5μmol·m-2·s-1 radiation for 0; 360, 720, 1080, and 1440 h. The plants were transferred to the greenhouse where their growth internode length and bud number were evaluated during 2 months. It was verified that there was an increase up to 697% in the height of the plants when they were treated for 1440 h, independently of the temperature. The internode length was also larger when the plants were treated for greater periods. The temperature of 10 ± 1 °C led to a decrease in the bud number, while at 4 ± 1 °C, significant differences were not observed. These results suggest that the use of higher temperatures (10 ± 1 °C), can also recover the plant growth during the acclimatization process.
This work was carried out in the Tissue Culture Laboratory of Embrapa Temperate Climate aiming to maximize the protocol for in vitro culture of potato cv. Baronesa. The treatments consisted of multiplication of microcuttings with one, two, or three buds with/without leaves and originated from different regions of the shoot: apical, middle, or basal. Each treatment was repeated five times with each replication composed of five explants that were inoculated in 250-ml flasks with 40 ml of the medium containing MS salts and vitamins added to: sucrose (30 g·L-1), myo-inositol (100 mg·L-1), agar (6 g·L-1). The pH was adjusted to 5.6 before autoclaving. After inoculation, the flasks remained in a growth room at 25 ± 2 °C, 16-h photoperiod, and 19 μmol·m-2·s-1 light intensity provided by cool-white fluorescents lamps. Observations were done every 5 days. Final evaluation was performed after 30 days. It was observed that basal microcuttings provided longer shoots and that microcuttings with leaves bore the best ones. This kind of explant also favored a higher number of shoots, axilary buds, and better multiplication rate. The presence of leaves in the microcutting is important when basal explants are used once it can improve the number of axillary buds and the rate of multiplication. The higher the number of buds in the microcutting the lower the rate of multiplication. The in vitro multiplication of potato could be improved by using one-leaf bud basal microcutting.
The purpose of this study was to adapt an ELISA test for diagnosing of “Apple Chlorotic Leaf Spot Virus” (CLSV) in apple trees. This work was carried out at Centro de Pesquisa Agropecuária de Clima Temperado–CPACT/EMBRAPA, Pelotas–RS, Brazil, during the 1996 spring season. The application of ADGEN Diagnostic Systems protocol does not give some positive results from diseased apple trees. The procedure modified by FLEGG & CLARK (1979) gives an unsatisfactory result for color reaction in the positive samples. It means it is necessary to adapt this methodology. When the antigen was obtained from leaves grown from the base to the intermediate position in the stem and grounded with extracting buffer—0.02 M, pH 7.4 (1 g tissue: 3 ml extracting buffer) and polyclonal antisera and antibody alkaline phosphatase conjugate was diluted in coating buffer—0.05 M, pH 9.6 (1 μg antisera or antibody: 500 μl coating buffer) the reaction become more intensive and the test was able to diagnosticate the presence of the pathogen in infected leaves of apple trees.
Three different leaf segments (apical, basal, and middle) were treated in combination with aluminum at 0, 5, 10, 15 and 20 mg·L-1. Three kinds of leaf segments were inoculated in flasks in 12 replicates, with the adaxial surface touching the medium composed by basic macro- and micronutrient and MS vitamins added to 2,4-D (1.0 mg·L-1); BAP (5.0 mg·L-1); sucrose (30.0 g·L-1); myo-inositol (100.0 mg·L-1) and agar (6.0 g·L-1). The pH was adjusted to 4.0 before autoclaving. After inoculation, the explants were incubated in a dark growth room for 21 days and then, placed during 80 days, at 25 ± 2 °C, 16-h photoperiod provided by white fluorescent lamps under 19 μE·m-2·s-1 radiation. At the end of this period, the explants were evaluated. It was observed that basal leaf explants provided greener callus and that the heavier ones came from the middle leaf explants. Absence of Al or high Al concentrations favored the number of adventitious buds, whereas intermediate concentrations inhibited them. The absence of Al favored basal explants to form adventitious shoots, while lower concentrations favored apical and basal segments. High Al concentration appear to stimulate adventitious shoots in the basal and middle explants. Although it was evident that callus intensities were lower in higher Al concentration, Al is not so harmful to callogenesis and organogenesis.
Garlic (Allium sativum L.) belongs to the Alliaceae family and originated from Asia and Mediterranean countries. Their bulblets are rich in starch and aromatic substances. The rate of garlic propagation in field conditions takes several years for the production of a certain number of seed bulbs for the release of a new variety. The use of tissue culture techniques is a useful tool for overcoming this problem. The aim of this work was to increase the mean number of shoots derived from the meristem isolation and to verify the percentage of callus formation and to analyze vigor of the material. The initial meristems were inoculated in a salt and vitamin B5 media except for the iron element, which was provided by MS medium added to in mg·L-1: myo-inositol (100.0), nicotinic acid (1.0), piridoxine (1.0), thiamine (10.0), sucrose (20.0 g·L-1), agar (6.0 g·L-1). BAP and TDZ were added at: 0.0; 1.0; 1.5; 2.0; and 2.5 μM This material remained in a growth room for a 16-h photoperiod, radiation of 20 μMol·m-2·s-1 and 25 °C for 40 days. Although `Sao Marcos' produced more vigorous shoots, no significant difference was found for the mean number of shoots. `Sao Valentim' cultivar shows more callus at the shoot base, making this cultivar more prone to somaclonal variation On the other hand, BAP estimulates the appearance of callus, but it has been shown that this is cultivar-dependent.
Aiming to improve plant growth of the apple rootstock cultivar Marubakaido (Malus prunifolia) in greenhouse, 1-year-old plants were sprayed once, twice, and three times in a 7-day interval with gibberellic acid (GA3) in the following concentrations: 0, 50, 100, 200, 400, 800 and 1600 mg•L-1. The plant growth was evaluated every 2 weeks during 2 months. The internode length, bud number, and the dry weight of the aerial part were also evaluated at the end of the experiment. It was verified that GA3 sprayed at 800 mg•L-1 by three times consecutively was the best treatment presenting the largest rate of plants growth (912% against 114% of nontreated plants) in relation to their initial height, besides providing larger internode length and dry matter weight of the aerial parts. However, using this regulator did not affect the plant bud number. Plants sprayed once did not present significant response to GA3 for any of the studied variables. These results suggest that the use of GA3 in 1-year-old apple plants reactivates growth, although, the increase in the number of applications associated with higher doses is necessary to improve the efficiency of this product.
Asparagus is a vegetable that presents an increase in yield when propagated by meristem culture. On the order hand, the rooting phase in asparagus is greatly affected by the previous phase, i.e,. multiplication. This species presents a better rooting performance when callus is formed at the shoot base. So, the aim of this work was to evaluate treatments during the multiplication phase, which also leads to callus formation at the shoot base. The initial explants came from shoots being cultivated in vitro. It was tested kinetin at: (0.0, 0.5, 1.0, 1.5, and 2.0) μM; ancymidol at (0.0 and 0.5) μM and NAA at (0.0 and 0.5) μM for both genotypes, which were cultured in a MS medium added to sucrose (30 g·L–1), agar (6.0 g·L–1) and myo-inositol (100.0 m g·L–1). Shoots bearing two buds were inoculated in 10-ml test tubes and placed in a growth room for 30 days when they were evaluated. The addition of kinetin significantly improved the number of buds and at 1.3 μM this growth substance presented the best results as number of shoots is concerned. NAA application promoted a negative effect on spear bearing. The addition of ancymidol in this phase did not improve the bud multiplication. It was shown that clone M14 performed better than the hybrid cv. Deco as multiplication is concerned.
The potato cultivar Cristal has recently been released by the CPACT/EMBRAPA Breeding Program. Such cultivar was selected for having high dry matter and low sugar content, which makes it desirable for the chip industry. However, this is a recalcitrant cultivar as far as in vitro multiplication is concerned. The aim of this work was to improve the rate of multiplication for this cultivar when it was submitted to different MS salt and sucrose concentrations in the culture media. Two-bud microcuttings were inoculated in test tubes (20 × 150) mm with 10 ml MS media at 3/4-, 1/2-, and full-strength and MS vitamins added to: myo-inositol (100 mg·L–1), agar (7.0 g·L–1) and sucrose as follows: 10, 20 and 30 g·L-1. Each treatment was repeated eight times and each replicate had eight explants. After inoculation the whole material was kept in a growth room at 25 ± 2°C, 16-hr photoperiod and 2000 lux. The evaluation was done 35 days later. It was found and increase in the number of buds as the sucrose concentration in the media decreased. As far as MS salts are concerned no difference in bud number was observed. The rate of multiplication was slightly higher for MS media at full strength and sucrose at low concentration (10 g·L–1). This treatment could be recommended for this cultivar.
The potato cultivar Cristal recently released by the CPACT/EMBRAPA Breeding Program has high dry matter and low reduce sugars. These are desirable characteristics as industry processing is concerned. Nevertheless, this is a recalcitrant cultivar. The meristem culture is difficult to establish along with a very low multiplication rate. The aim of this work was to improve the multiplication rate for this cultivar. Two-bud microcuttings derived from apical, mid, and basal regions were inoculated in test tubes with 10 ml MS culture media and vitamins as follows; myo-inositol (100 mg·L–1); sucrose (10 g·L–1). No growth regulator was added. All treatments were placed in a growth room in a 16-hour photoperiod; 25 ± 2°C and 2000 lux. One month later, although it was observed that the final growth was more pronounced for basal microcuttings, no difference could be detected for number of shoots and multiplication rate. It was concluded that it makes no difference whatsoever kind of microcutting is used to start the micropropagation process.