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Resistance gene Sw-5 of tomato confers resistance to TCSV in Solanum melongena
41-47.Views:137Eggplants transformed with Sw-5 gene, regenerated by organogenesis and somatic embryogenesis, were resistant to the Tomato chlorotic spot virus, while wild plants did present systemic infection. TO plants were selfed and the segregation analysis of T1 and T2 generation indicated the existence of one or more insertion sites. Southern blot analysis confirmed one or two independent insertions in T2 plants. Different lesions associated with the insertion number were observed in TI and T2 plants. T2 plants with two copies displayed faster hypersensitive reactions and characteristic necrotic lesions that contrasted with slower responses and necrotic ring lesions in plants with one copy. These results suggest that the Sw-5 confers resistance to tospovirus in transgenic eggplants and that the resistant phenotype depends on the number of transgene copies.
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Comparative investigations on protoplast culture of some Brazilian and Hungarian sweet pepper cultivars and hybrids
39-45.Views:177Cotyledon protoplasts were isolated from 16-18-day-old in vitro grown seedlings of 9 Brazilian and 3 Hungarian pepper varieties and hybrids. Large numbers (average 9.59 X 106 protoplasts g 14 fresh weight) of highly viable (average 87.0%) protoplasts were released using a pectocellulolytic enzyme mixture. Protoplasts were cultured in K8p mediuni using an alginate disc embedding method. The osmotic pressure of the medium surrounding the alginate-embedded protoplasts was reduced by replenishing the liquid medium at K8p:K8 ratios of 1:0. 2:1, 1:1 in the first. second, and third week, respectively. Initial plating efficiency (IPE) average was 38.5% and after 21 days protoplasts reached microcolonies (15-20 cells) stages. Microcolonies were transferred after 3-4 weeks to a MS-based medium supplemented with 1.0 mg I-1 zeatin, 3.0% (w/v) sucrose, 0.24% (w/v) phytagel and pH 5.8, whereupon they formed callus. Final plating efficiency (FPE) average was 0.29% at a plating density of 1.0 x 105 protoplasts Protoplast-derived calli were cultured on a range of MS-based media supplemented with either BAP, IAA, TDZ; and zeatin. No morphogenic response was observed in any genotype investigated.
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Rhizogenesis in in vitro shoot cultures of passion fruit (Passiflora edulis f. flavicarpa Deg.) is affected by ethylene precursor and by inhibitors
47-54.Views:167The effects of the ethylene precursor ACC and two inhibitors, AgNO3 and AVG, on root formation were tested in in vitro shoots of passion fruit (Passiflora Midis f.flavicalpa Deg.). The organogenic response was assessed on the basis of percentage of shoot-forming. roots, root number and length. The time course of ethylene production was also monitored. ACC inhibited root formation by delaying root emergence and increasine, callus formation at the basis of the shoots. In addition, ACC caused a marked increase in ethylene production, coupled to leaf chlorosis and senescence with lower rooting frequencies, number and length of roots. IAA supplementation increased ethylene production. Both ethylene inhibitors, AgNO3 and AVG, at appropriate concentrations reduced callus formation at the basis of shoots. AVG increased the number of roots per shoot, but drastically reduced length of differentiated roots. Regarding to leaf pigments, ACC promoted a marked reduction on carotenoids and total chlorophyll, whereas AVG and AgNO3 delayed explant senescence and pigments degradation, not differing from IAA supplemented and non-supplemented control treatments. The results confirm previous reports on the beneficial effects of ethylene inhibitors on in vitro rooting and suggest its reliability to be used as an alternative approach to evaluate sensitivity of Passiflora species to ethylene.
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Adaption of temperate climate horticultural plants in tropical and subtropical developing countries (Review Article)
7-11.Views:187Adaption of temperate climate horticultural plants in tropical and subtropical developing countries (Review Article)
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Biotechnologies for ornamental plants: some insights to the Brazilian productive chain
51-59.Views:250The world industry of ornamental plants is under wide transformations regarding the changes in the cultivation, management, postharvest technologies and the use of new (bio)technologies to assist the improvement and development of new varieties. This industry worth more than US$ 20 billion, but Brazil shares only 1% of this value. To compete at this market with permanent technological innovation, the country needs to be tuned in with the progresses in the biotechnologies applied to the productive chain of ornamental plants. In this revision, we analyze the Brazilian and world ornamental market emphasizing the role of the biotechnologies in the modernization and increase of the competitiveness of the sector.
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Influence of antiobiotics on NAA- induced somatic embryogenesis in eggplant (Solanum melongena L. cv. Embil)
88-95.Views:156The influence of increasing concentrations of naphthaleneacetic acid and the antibiotics cefotaxime, timentin, kanamycin, and hygromycin on eggplant (Solantun melongena L. cv. Embil) somatic embryogenesis was investigated. Cotyledon explants were excised from 16 to 20 days old in vitro grown seedlings. NAA promoted somatic embryogenesis, although its concentrations had no influence on the mean number of embryos. Callusing decreaSed significantly with increasing NAA concentrations. Morphogenesis was stopped with 50 to 100 mg L-1 kanamycin and 7.5 to 15 mg L-1 hygromycin. Although early globular embryos were observed up to 15 mg L-1, further embryo development was inhibited at 10 mg L-1. Interestingly, cefotaxime (250 and 500 mg L-1) promoted a marked effect on enhancing fresh weight of calli, accompanied by decrease in embryo regeneration, whereas timentin concentrations (150 and 300 mg L-1) did not affect embryo differentiation as compared to the control treatment.
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Allelopathic effect of the Cladonia verticillaris lichen extracts and fumarprotocetraric acid on the early growth of germinating seeds and seedlings in Allium cepa L.
31-35.Views:152The allelopathic activity of the different extracts of the lichen Cladonia verticillaris and fumarprotocetraric acid on the early growth of A cepa (IPA 6) seedlings depends on their chemical composition and concentration, respectively. It was observed that the length of the radicle was significantly stimulated by fumarprotocetraric acid at high concentrations and by the total extract of C. verticillaris thalli, which contained a high level of fumarprotocetraric, acid confirmed by HPLC-technique. In addition, it was found, that the phosphate buffer extract, which contained high level of methyl (3-orcinol carboxilate measured by HPLC, reduced the length of the hypocotyls significantly. Under our experimental conditions there was no influence of the different types of extract and fumarprotocetraric acid on the ratio of seed germination, in relation to the control. From the study of HPLC it was found that fumarprotocetraric acid and methyl 13-orcinol carboxilate were present in all extracts at different concentrations, depending on the method of extraction.
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Physiological and biochemical evolution of peach leaf buds during dormancy course under two contrasted temperature patterns
15-19.Views:114Budbreak anomalies in temperate fruit trees grown under mild conditions have often been described. However, only few authors approached the physiological evolution of leaf buds all along the dormancy period according to the temperature pattern. The aim of this study was to characterize the evolution of peach leaf bud dormancy through some physiological and biochemical parameters under temperate winter conditions and under total cold deprivation after the endodormancy onset. Two treatments were applied in peach trees cv. Redhaven: (i) Regular Chilling Amounts — RCA and (ii) Total Chilling Deprivation — TCD. Buds were sampled periodically from different parts of the stem (terminal, medium and basal ones). We recorded the evolution of: carbohydrate concentrations (glucose, fructose, sucrose, sorbitol and starch), respiration rate, water contents and energy metabolism (ATP and ADP ratio). The dynamics of these parameters were compared and correlated with dormancy evolution ("one node cuttings" test) and budbreak patterns in plank:. The endodormancy intensity of terminal buds was significantly lower than those of median and basal buds in early October. Under RCA treatment, this gradient faded and the bud endodormancy release was completed at the same time in all positions along the stem. Thereafter, the "cuttings" test indicated that terminal buds grew slightly faster than median and basal buds, and, consistently, budbreak in planta started with the terminals buds, followed by the medians and then by the basal ones. The carbohydrate contents showed a transitory change only when the buds began to grow after the endodormancy was released under RCA. Respiration, water content and ATP/ADP changed dynamics only under RCA and only after the end of the endodormancy (their respective changes were very parallel). The dynamics of none of the tested parameters could be related with the endodormancy dynamics, but respiration, water content and ATP/ADP could be consistent markers of the actual bud growth before bud break (in this respect, ATP/ADP could not show differences between the terminal and axillary buds while respiration and water content could).
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Viniculture in the Semi-arid Tropical Region of Brazil
115-118.Views:103In the semi-arid tropics viticulture was successful according to technologies developed by Hungarian expertise
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Nutritional quality, fruit shape and relationships among exotic and local Capsicum pepper genotypes in Uganda
33-39.Views:328Twenty-one hot pepper genotypes comprising of local (15) and exotic (6) types (C. annuum, C. frutescens and C. chinense) were characterized for selected fruit traits after propagation in a glasshouse at the Makerere University Agricultural Research Institute Kabanyolo in Central Uganda using a completely randomized design with three replicates. Ripe fruits were harvested and analyzed; traits evaluated were all significantly different at P<0.05 with variations in quality attributes. The genotype OHA-B305-10 had the highest ascorbic acid content (128.86 mg/100 g) and is recommended for improvement of both local and exotic genotypes targeting the fresh market. Genotypes CAP0408-12 and UG2 WE0511-22, with highest total soluble solids (16.17 ºBrix) and dry matter content (28.59%), respectively should be used in improvements for industrial use or processing to products such as chilli powder or flakes. BRS-M205-04 with highest titratable acidity (1.04%) can be used in enhancing shelf life of genotypes with low titratable acids as well as for the fresh market. In spite of the intraspecific relationships among genotypes, significant differences were observed in their quantitative traits. These genotypes will, therefore, be useful in improving the quality of hot pepper fruit in Uganda.