Highest Survival Percentage Research Articles

Embriogénesis somática en el cultivar de plátano ‘FHIA – 25’ (AAB) a partir de ápices meristemáticos

<p>El cultivar de plátano ‘FHIA – 25’ (AAB), posee excelente rendimiento y alta resistencia a “Sigatoka negra”, pero con la limitante del bajo contenido de azúcar en su fruto, lo cual hace que sea necesario disponer de un método de regeneración de plantas a nivel celular como la embriogénesis somática, que se complemente a técnicas biotecnológicas de transformación genética para mejorar la calidad del fruto. El presente trabajo se realizó con el objetivo de establecer una metodología de regeneración vía embriogénesis somática a partir del explante inicial ápices de brotes axilares establecidos directamente en medio de cultivo líquido. Se obtuvieron suspensiones celulares embriogénicas homogéneas a partir del explante antes mencionado. Se lograron las mayores tasas de multiplicación a la densidad celular de 3,0%. La incubación de los embriones somáticos durante 30 días en el medio de cultivo de maduración permitió incrementar la germinación de los mismos. Durante la fase de aclimatización las plantas provenientes de los embriones somáticos, así como las plantas regeneradas por organogénesis, mostraron un alto porcentaje de supervivencia (98 y 97 %, respectivamente), sin la presencia de variación somaclonal.</p>

An ultra-rapid cryo-technique for complex organisms

The soil nematode Caenorhabditis elegans is an excellent research model in cell biology, human disease and developmental studies. In this study, a novel cryopreservation technique based on a rapid cooling procedure, previously established for juveniles, was applied to adult-worms. Here we demonstrated that adults of C. elegans, a complex metazoan organism, survive to a rapid cooling and storage in liquid nitrogen (−196 °C) with a very high survival percentage (85%). The procedure relies on a Low CryoProtectant Technique (LCPT) and Ultra Rapid Cooling (URC). The high cooling rate is achieved through the reduction of sample volumes and the effectiveness of a nylon carrier. Our technique complies with the requirements for vitrification to occur. The main distinctive characters of this cryopreservation technique compared to other methods, e.g. Slow Freezing and Vitrification, are presented. Our results show that this cryopreservation method is valid for both unicellular and multicellular organisms; it is suitable for short or long time storage in liquid-nitrogen. This technique promises to be a unique and simpler method for cryostorage of cells, organisms and tissues.

Micropropagation of a difficult-to-root weeping mulberry (Morus alba var. Shidareguwa): A popular variety for ornamental purposes

‘Shidareguwa’ mulberry (Morus alba var. Shidareguwa) has a graceful weeping canopy that is commonly used in landscaping. However, it has a low rooting ability when conventionally propagated, and a feasible micropropagation system has not yet been reported. This study focused on establishing an in vitro method for plantlet production of ‘Shidareguwa’ mulberry. Explant types, media, and plant growth regulators (PGRs) were evaluated for their effects on shoot initial culture and multiplication, along with in vitro and ex vitro rooting and survival rate after acclimation and transfer into the field. Shoot tip explants had the highest survival percentage in initial culture. The largest shoot growths were cultured on Murashige and Skoog (MS) medium with 2% sucrose and 4.44μM 6-benzylaminopurine (BAP) for 20 days. The best shoot multiplication was achieved using MS medium with 3% sucrose and 4.44μM BAP for 30 days. The highest rooting induction (90%) in vitro was achieved using MS medium with 3% sucrose without auxins for 30 days. The well-rooted plantlets obtained in vitro had a 94% survival rate after acclimation. All young shoots from field-grown trees failed to root, but explants from in vitro regenerated shoots showed 100% root induction ex vitro when cultured in same media. These shoots dipped in 2000ppm IBA exhibited the greatest rooting performance. Ex vitro plants exhibited greater rooting ability, efficiency, and survival after the first acclimation than in vitro plants. We present a novel and feasible method of plantlet production through in vitro propagation of shoot tips.

Potential of Chitosan for the Control of Tomato Bacterial Wilt Caused by Ralstonia solanacearum (Smith) Yabuuchi et al

Bacterial wilt is an important constraint to tomato production. The search for an effective and safe method of managing bacterial wilt is imperative. Chitosan, adeactylated chitin was reported to possess direct antimicrobial property against certain pathogens and is a plant resistance booster. This study was conducted to: evaluate the effectiveness of varying chitosan concentrations and sources against bacterial wilt in vitro and in vivo and compare different application methods in bacterial wilt control. Varying chitosan concentrations (100, 200, 300, 400 and 500 ppm) immersed/dissolved in water, 1% acetic acid, and streptomycin were evaluated against R. solanacearum in laboratory and pot experiments. Three chitosan sources were also evaluated against the pathogen. Different methods of application were compared. Regardless of source, chitosan in water has no direct antimicrobial activity against R.solanacearum but when dissolved 1% acetic acid, it was able to inhibit the bacteria. Inhibition of chitosan/acetic acid was best at 300 ppm and significantly higher than 1% acetic acid alone indicating that its antimicrobial property was enhanced by the acid. Two hundred ppm chitosan/acetic acid-treated plants delayed the onset of disease and produced the lowest percentage infection, lowest disease severity rating, and highest percentage survival in inoculated tomato. The action of 200 ppm chitosan/acetic acid treatment was due to a dual effect, i.e., antimicrobial and as an elicitor of resistance. All application methods were effective in controlling bacterial wilt but one time root dipping to 200 ppm chitosan/acetic acid before transplanting was enough to protect the plants against the disease.

Conservation and Cultivation of Ferula jaeschkeana Vatke: A Species with Deep Complex Morphophysiological Dormancy

Ferula jaeschkeana Vatke, an important medicinal plant of the Himalayan region, being threatened needs immediate conservation strategies. Keeping this in view studies on the germination of seeds and sprouting of vegetative propagules has been undertaken for the first time. At the time of dispersal, F. jaeschkeana seeds are dormant and have under-developed embryos. The aims of the present work were to determine the requirements for germination and overcoming dormancy and to characterize the type of seed dormancy. The seeds of F. jaeschkeana have deep complex morpho-physiological dormancy. Present study revealed that final germination percentage, mean daily germination, seed vigour index, germination index, germination rate and germination value were highest (53.3 %, 0.88, 3.67, 0.13, 0.88 and 1.02, respectively) when 200 ppm kinetin and dry stratification (60 days) were applied together. The decline in MGT up to 36.18 days and highest percentage survival (87.9 ± 7.08) were also observed in the same treatment. This treatment is thus recommended for promoting the germination process of F. jaeschkeana seeds. Maximum seed germination (62.0 ± 11.54 %) at 1 in. depth was found in seeds presoaked in kinetin (100 ppm) for 24 h in media of sand:soil (2:1). In case of root tuber cuttings, 500 ppm gibberellic acid showed significantly high sprouting (89.70 ± 0.78 and 69.14 ± 0.82 %, respectively) and rooting percentage (78.78 ± 1.13 and 55.56 ± 0.95 %, respectively) in case of both perennial and biennial plants. Likewise minimum time taken for sprouting was also observed in the same treatment in case of both perennial (10.0 ± 1 days) and biennial plants (11.33 ± 2.3 days).

Temperature induction response reveals intrinsic thermotolerant genotypes in soybean

The responses of soybean genotypes to high temperature for intrinsic tolerance was studied using Temperature Induction Response (TIR) technique in order identify the genotypes tolerant to high temperature stress. Seven soybean genotypes subjected to lethal and sub lethal temperatures showed significant variation for acquired thermotolerance. Thermotolerant genotypes ADT 1 and CoSoy1 identified by the TIR technique, demonstrated higher survival percentage, and lower growth reduction. Further the tolerant genotypes identified based on TIR also showed higher antioxidant enzymes activity implying the critical role of antioxidant in cellular thermotolerance. This clearly demonstrated that TIR can be effectively used for screening high temperature tolerance genotypes in soybean. This study also established the fact that the alternations in antioxidants during induction are vital for imparting tolerance to high temperature stress.

25 lat doświadczeń w leczeniu oszczędzającym u kobiet chorych na raka piersi we wczesnych stopniach zaawansowania

Aim of the study . Evaluation of long term results, the identification of the causes of the treatment failure and prog­nostic factors in women with early invasive breast cancer after breast conserving treatment. Material and methods . 1425 women with an early invasive breast cancer after breast conserving treatment under­went postoperative radiotherapy in the Department of Radiotherapy of The Maria Skłodowska-Curie Memorial Cancer Center in Warsaw. Duration of the symptoms before diagnosis ranged from 0 (the tumor was found incidentally by mammography or ultrasound scan) to 84 months. In 1204 patients the size of the tumor did not exceed 2 cm. Most frequent localization was in external quadrants. 3 to 24 weeks after surgery all patients underwent breast irradiation with Co-60 or photons X 4–6 MeV in the dose of 42.5–50 Gy and next, 1405 of them received additionally 10–20 Gy to the site of the removed tumor, mostly with electrons of 9–15 MeV. In 489 the treatment was combined with chemo­therapy and in 592 patients with hormone therapy. Results . The tolerance of the treatment was good. In 1357 (95%) women the cosmetic effect of the treatment was evaluated as very good and good. 15-years overall survival (OS) rate was 85% and disease free survival (DFS) rate was 79%. 15-years local recurrence rate risk was 6.9% and distant metastases occurred in 12.7%. Unfavourable prognos­tic factors were: size of the tumor being more than 2 cm (T2), metastatic axillary lymph nodes (N 1–2), ductal type carcinoma and beginning of the treatment before the year 2006. Conclusions . Breast conserving treatment is a safe and well tolerated method providing a high percentage of overall and disease free survival as well as good and very good cosmetic effects. Failure of the breast conserving treatment is relatively rare and is mostly due to the generalisation of the disease. The prognosis in this group of patients depended on: the size of the primary tumor, presence of metastatic axillary lymph nodes, a ductal type of the cancer and timing of the beginning of treatment.

Parenteral immunization of PLA/PLGA nanoparticle encapsulating outer membrane protein (Omp) from Aeromonas hydrophila: Evaluation of immunostimulatory action in Labeo rohita (rohu)

Advanced vaccine research approaches needs to explore on biodegradable nanoparticles (NPs) based vaccine carrier that can serve as antigen delivery systems as well as immuno-stimulatory action to induce both innate and adaptive immune response in fish. Immunogenicity of PLA and PLGA NPs encapsulating outer membrane protein (Omp) antigen of Aeromonas hydrophila were evaluated through intra-peritoneal injection in fish, Labeo rohita. Antigen loaded PLA-Omp (223.5 ± 13.19 nm) and PLGA-Omp (166.4 ± 21.23 nm) NPs were prepared using double emulsion method by efficiently encapsulating the antigen reaching the encapsulation efficiency 44 ± 4.58% and 59.33 ± 5.13% respectively. Our formulated PLA Omp and PLGA-Omp NPs were in nanometer range (<500 nm) and could be successfully endocyted in the body. Despite low antigen loading in PLA-Omp, it showed considerably slower antigen release in vitro than PLGA-Omp NPs. Other physical properties like zetapotential values and poly dispersity index (PDI) confirmed the stability as well as monodisperse nature of the formulated nanoparticles. The spherical and isolated nature of PLA-Omp and PLGA-Omp NPs were revealed by SEM analysis. Upon immunization of all antigenic formulations (PLA-Omp NP, PLGA-Omp NP, FIA-Omp, PLA NP, PLGA NP, PBS as control), significant higher bacterial agglutination titre and haemolytic activity were observed in case of PLA-Omp and PLGA-Omp immunized groups than rest groups at both 21 days and 42 days. The specific antibody response was significantly increased and persisted up to 42 days of post immunization by PLA-Omp, PLGA-Omp, FIA-Omp. PLA-Omp NPs showed better immune response (higher bacterial agglutination titre, haemolytic activity, specific antibody titre, higher percent survival upon A. hydrophila challenge) than PLGA-Omp in L. rohita confirming its better efficacy. Comparable antibody response of PLA-Omp and PLGA-Omp with FIA-Omp treated groups suggested that PLA and PLGA could be replacement for Freund's adjuvant (for stimulating antibody response) to overcome many side effects offering long lasting immunity. Our encouraging results suggest that PLA/PLGA nanoparticles based delivery system could be a novel antigen carrier for parenteral immunization in fish.

Effect of dietary supplementation of Bacillus subtilis on haematological and immunological parameters of Catla catla (Hamilton)

Effect of dietary supplementation of a Gram-positive, aerobic, probiotic bacterium Bacillus subtilis on the immunohaematological indices during pre- and post-challenge in Indian major carp, catla (Catla catla), was studied. The B. subtilis was administered orally at four different doses 1.0 × 106 (T1), 1.0 × 107 (T2), 1.0 × 108 (T3), and 1.0 × 109 (T4) cfu g−1 feed to C. catla for 90 days. The positive control (Cp) and negative control (Cn) were fed with feed without B. subtilis for the same period. On the 60th day, blood and serum were sampled to determine various haematological and serum parameters. Fish were challenged intraperitoneally with Aeromonas hydrophila after 60 days in all the treatment groups and Cp, while the Cn was challenged with phosphate-buffered saline (PBS, pH 7.2) only. Dietary supplementation of B. subtilis leads to the rise of various immunological and haematological parameters in catla during the pre- and post-challenge. During pre-challenge, the highest TEC (1.30 ± 0.02 × 106 cells mm−3), haemoglobin (7.43 ± 0.25 g %), total serum protein (3.89 ± 0.08 g dL−1), and serum lysozyme activity (8.39 ± 0.01 µg ml−1) were recorded in fishes fed feed containing B. subtilis at 1 × 109 cfu/g feed (T4). The highest survival percentage (86.33 %) was also observed in T4 group. The significantly increased survival percentage (P < 0.05) of B. subtilis-treated groups in comparison with control group (Cp) suggests that dietary supplementation of this probiotic bacterium can protect catla from A. hydrophila infection by enhancing innate immunity.

In vitro regeneration of Citrus hystrix DC

An efficient plantlet regeneration system for Citrus hystrix DC has been developed in this study. N6-benzyladenine (BA) was most commonly used plant growth regulator in micropropagation of Citrusspp. However, our study demonstrated that BA alone was insufficient to induce normal in vitro shoot regeneration of C. hystrix due to the occurrence of leaf senescence on the regenerated shoots. The inclusion of silver nitrate (AgNO3) at 10.0 µM into Murashige and Skoog (MS) medium containing 2.22 µM BA could effectively overcome the leaf senescence and improved shoot regeneration from different explants (cotyledonary node, cotyledon, hypocotyl and primary root) of C. hystrix. In the rooting experiment, the application of continuous indole-3-butyric acid (IBA) and naphthaleneacetic acid (NAA) treatment of 4.92, 9.84, 14.76, and 19.69 µM IBA or 1.34, 2.69, and 5.37 µM NAA in combination with 20.0 µM AgNO3 resulted in poor rooting of C. hystrix shoots. Rooting was significantly improved upon exposure of shoots to IBA pulse treatment of 9,840 µM for 16 h prior to their transfer on MS medium supplemented with 20.0 µM AgNO3. Assessment of various potting mixtures for acclimatization showed medium containing loamy soil: Peatgro: sand (1:1:1; v/v/v) produced high percentage (83.3 %) of plantlet survival.

Effects of dietary microbial levan on growth performance, RNA/DNA ratio and some physio-biochemical responses ofLabeo rohita(Hamilton) juveniles

Six isonitrogenous and isocaloric semi-purified diets were prepared with different levels of microbial levan: control (Basal), T1 (Basal + 2.5 g kg−1 diet), T2 (Basal + 5 g kg−1 diet), T3 (Basal + 7.5 g kg−1 diet), T4 (Basal + 10 g kg−1 diet) and T5 (Basal + 12.5 g kg−1 diet), fed to six groups of fish in triplicate tanks. The results of the 60 days feeding trail showed that supplementation of dietary levan significantly affected the weight gain percentage and specific growth rate of the treatment groups fed at 10 g kg−1 or more levan. Lowest feed conversion ratio (FCR) value and highest survival percentage among levan fed groups were observed with 12.5 g kg−1 incorporation (T5) and was comparable with (T4) group. Significant increase in muscle RNA level and RNA/DNA ratio was observed with the increasing dietary levan. Fish fed 12.5 g kg−1 levan had significantly higher protease, amylase and lipase activities compare with the control group. Lowest Aspartate aminotransferase (AST) activity in the liver and muscle was observed in the T5 group fed with highest level of dietary levan. Overall results conclude that dietary microbial levan incorporation at 12.5 g kg−1 could be used as potent dietary prebiotic for the culture of L. rohita juveniles.

Effects of Supplementation Diet Containing Microcystis aeruginosa on Haematological and Biochemical Changes in Labeo rohita Infected with Aeromonas hydrophila

An experiment of 100 days duration was conducted to test the effect of Microcystis aeruginosa in Labeo rohita against Aeromonas hydrophila. The rohu fingerlings (22 ± 2 g) were fed with the experimental diets incorporated with different concentrations of M. aeruginosa @ 0 g kg-1, 0.5 g kg-1, 1 g kg-1 and 5 g kg-1. Replicate groups of fish were fed for three month daily @4% body weight. At an interval of 30 days blood and serum samples were assayed for different haematological [total erythrocyte count (TEC), total leucocyte count (TLC), haemoglobin] and biochemical [blood glucose, serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP)] parameters. Significantly (p ≤ 0.05) increased haemoglobin content and TLC was observed in Microcystis treated group. It was observed that the serum AST activity was significantly (p ≤ 0.05) decreased to all the treated groups of fish as compared to control on entire assay period. Serum ALT activity was significantly (p ≤ 0.05) different to all the treated groups of fish on day 60, on day 90 and on day 10 (except group B) bacterial post challenge as compared to control. After 90 days, fish were challenged with A. hydrophila and mortality (%) was recorded up to day 10 post challenge. Highest percentage of survival (72%) was noticed in the group fed 1.0 g Microcystis kg-1 dry diet. The present study suggests that the administration of bluegreen algae, Microcystis aeruginosa supplementation diets for 100 days protects the hematological and biochemical parameters in L. rohita from A. hydrophila.

Effect of different IBA levels on air layering of karonda (Carissa carandasL.)

The present investigation was conducted at Commercial Fruit Nursery, College of Horticulture, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during three years (201013). The study was undertaken with objectives to study the effect of different IBA levels on rooting and survival of karonda air layering and to find out the suitable IBA level for rooting and survival of karonda air layers. The experiment was laid out in randomized block design. The treatments consisted of six different levels of IBA (1000, 2000, 3000, 4000, 5000 and 6000 ppm) and one control, replicated thrice. The results of three years pooled data revealed that different levels of IBA had significant effect on root and shoot characters of karonda air layers. IBA 5000 ppm was effective with respect to minimum days for rooting (10.73 days), increased number of roots per layer (102.55), height of rooted layers (44.53 cm) and number of leaves (145.77). In addition, root to shoot ratio (1.17) and highest survival percentage (90.82%) were recorded in 5000 ppm IBA treatment. However, least values for these characters were associated with control treatment. IBA 6000 ppm was also found effective with respect to days required for rooting, rooting percentage and survival percentage next to IBA 5000 ppm treatment. Thus, it is worthwhile to use 5000 ppm IBA for commercial multiplication of karonda through air layering.

Antiviral Treatment in Patients with HCV-Associated Lymphoproliferative Disorders

Clinical course of HCV infection may be connected with extra-hepatic manifestations associated with lymphoproliferative disorders as mixed cryoglobulinemia (MC) and non-Hodkin B cell lymphoma (B-NHL). The incidence of HCV infection in MC patients exceeds 80%, and among patients with B cell non-Hodgkin's lymphoma 10-17%, whereas this frequency is correlated with the prevalence of HCV in different geographic regions. 2015 European Association for the Study of the Liver (EASL) recommendations on Treatment of Hepatitis C prioritizes therapy of patients with extra-hepatic manifestations of HCV infection regardless of liver fibrosis. Antiviral treatment resulted in HCV RNA serum disappearance and tumor regression in the majority of patients with indolent B-NHL. It was revealed the high percentage of 5-year overall survival (OS), and 5-year progression-free survival (PFS) for the treated patients. Antiviral therapy improved the prognosis of lymphoproliferative disease, independent of its histological form. Due to the higher than in the general population, incidence of HCV infections in patients with haematological malignancies, it is desirable to test towards the infection all patients with B-NHL. Antiviral therapy should be considered as a therapeutic option for patients with indolent B-NHL who do not require intensive cytoreduction, because effective anti-HCV treatment induces lasting B-NHL clinical remission. It is also recommended to test towards the HCV infection and carry out an examination evaluating the anti HCV treatment in patients with acute and chronic lymphocytic leukemia (ALL and CLL).

Comparison of teosinte (Zea mexicana L.) and inter-subspecific hybrids (Zea mays L.×Zea mexicana) for high forage yield under two sowing regimes

This study was undertaken to evaluate the response of teosinte (Zea mexicana L.) and intersubspecific hybrids to heat stress, in particular productivity. Unlike maize (Zea mays L.), teosinte demonstrated thermophilic properties, namely lower heat injury, sustained chlorophyll content under heat stress (36−45°C) and high percentage survival of seedlings (at 55°C). Teosinte also had the ability to produce large plant biomass (27% and 55% higher yield than maize under non-stressed and stress conditions, respectively) and therefore could be exploited as a forage crop. However, teosinte forage had low animal intake (1.48 kg day–1) because of high pubescence density (10.38 view–1) and low sweetness (9.90°Brix). There was a high percentage of heterosis in variable intersubspecific crosses and traits, and a high magnitude of over-dominance for many traits, for example 5.93–7.06 for total biomass plant–1. Hybrids showed additional advantages, including high oil (20% and 4%) and protein (14% and 25%) contents compared with teosinte under non-stressed and stress conditions, respectively. Moreover, inter-subspecific hybrids were also resistant to heat stress, with the capacity for sustaining growth for a longer period (20% and 33% higher than maize under non-stressed and stress conditions, respectively). Genetic distance between parents—calculated from stable agronomic traits—could be used to select parents for high heterosis under both heat stress and non-stressed conditions.

Studies on growth and survival of stone grafts as influenced by age of seedling rootstock in mango (Mangifera indica L.) cv. Amrapali

Stionic relationship is an important factor for successful graft production. Stone grafting was performed by cleft method in the month of July-August on seedling rootstocks (Mango seedlings) of on four age groups i.e. 5 days, 10 days, 15 days and 20 days using Amrapali as scion stock at Kanpur district of Uttar Pradesh. The objective was to analyze age effect of mango seedling rootstock after stone grafting of cultivar Amarpali. Statistically data was analyzed with randomized block design replicating single interval five times. The height (24.4 cm) and sprouting percentage (83%) of scion, girth of rootstock and scion (6.3 mm) was significantly higher on grafts made on 10 days old rootstocks and minimum-sprouting percentage was recorded with 20 days old rootstocks. In vegetative parameters length (17.12 cm) and width (4.80 cm) of leaf was recorded maximum on 10 days old and minimum on 5 days old rootstock. The higher survival percentage was exhibited by 5 days and 10 days old rootstock, which shows suitability for this technique. It was revealed that stone/epicotyl grafting performed better in terms of growth and survival when rootstocks up to 10 days old were used for grafting.

Desenvolvimento de porta-enxertos de pessegueiro obtidos de miniestacas, em duas épocas, e sistema de cultivo sem solo

A propagação vegetativa comercial de mudas de pessegueiro por estaquia no Brasil tem sido limitada por alguns fatores, como a falta de técnicas apropriadas de manejo do ambiente de propagação, além da dificuldade no manejo da nutrição e da sobrevivência das estacas pós-enraizamento. Objetivou-se com o presente estudo avaliar o crescimento e sobrevivência de porta-enxertos de pessegueiro clonados através da miniestaquia, em sistema de cultivo sem solo, obtidos em duas épocas. Conduziu-se o trabalho em casa de vegetação e estufa agrícola localizadas no Campo Didático e Experimental do Departamento de Fitotecnia, Faculdade de Agronomia Eliseu Maciel, da Universidade Federal de Pelotas (UFPel/RS), no período de março - dezembro/2010 e novembro/2010 - maio/ 2011. O material vegetal utilizado para o enraizamento de miniestacas de pessegueiro foi obtido de ramos herbáceos de porta-enxertos de pessegueiro das cultivares Okinawa e Flordaguard. Miniestacas do porta-enxerto 'Flordaguard' obtidas no outono apresentaram maior porcentagem de sobrevivência quando transplantadas em sistema de cultivo sem solo. Miniestacas de porta-enxertos da cultivar Okinawa, obtidos no outono e na primavera, apresentam precocemente diâmetro adequado para a realização da enxertia. Os teores foliares de macronutrientes e micronutrientes seguiram uma ordem decrescente do pessegueiro, sendo N&gt;K&gt;Ca&gt;Mg&gt;P&gt;S e Fe&gt;Mn&gt;B&gt;Zn&gt;Cu.

In vitro development and acclimatization of dendezeiro (Elaeis guineensis)

Fruits and almond from the dendezeiro, oil palmbelonging to the Elaeis genus,are widely used for the production of cookingoils or for the pharmaceutical and cosmetic industries.In the last decade, this oil palm also emerged as a promising source for commercialbiofuel production. This study evaluated the effect of different culture media, MS (MURASHIGUE AND SKOOG) and Y3 (EEUWENS)and carbohydrates duringin vitro germination of zygotic embryos, the effect of growth regulators GA3, NAA and BA Ponin vitro seedling development, and the survival rate of acclimatized seedlingsof Manicoré hybrid (Elaeis oleifera x E. guineensis). Zygotic embryos were inoculated on MS and modified Y3 media, supplemented with different sucrose concentrations (30, 45, and 60 gL-1) or sorbitol (36 gL-1), and the germination rate was evaluated after 30 days. Subsequently, seedlings were transferred to modified Y3 culture medium supplemented with differentGA3 concentrations (3.5 and 7 mgL-1) or without it, combined or not with 1 mgL-1 of NAA, 5 mgL-1 of BAP.The highest germinationpercentage of germinated embryos (92%) was observed in MS medium supplemented with 36 gL-1 sorbitol. Culture media supplemented with growth regulatorsGA3, NAA and BAP promoted greater shoot lengththan control media. Rooted seedlings showed high survival percentage (85%) during acclimatization.

In vitro propagation and reintroduction of the endangered Renanthera imschootiana Rolfe.

Renanthera imschootiana Rolfe is an endangered tropical epiphytic orchid that is threatened with extinction due to over-collection and the loss of suitable habitats. In vitro propagation is a useful way to mass produce plants for re-establishment in the wild and for commercial propagation. Seeds collected 150 days after pollination (DAP) were the optimum stage for in vitro culture. Seed germination reached 93.1% on quarter-strength MS (i.e., MS containing a quarter of macro- and micronutrients) medium containing 0.5 mg l−1 α-naphthaleneacetic acid (NAA), 20% coconut water (CW), 1.0 g l−1 peptone, 10 g l−1 sucrose and 1.0 g l−1 activated charcoal (AC). Quarter-strength MS medium supplemented with 1.0 mg l−1 BA, 0.5 mg l−1 NAA, 1.0 g l−1 peptone, 10 g l−1 sucrose and 20% CW was suitable for the sub-culture of protocorm-like bodies (PLBs) in which the PLB proliferation ratio was 2.88. Quarter-strength MS medium containing 1.0 mg l−1 NAA, 1.0 g l−1 peptone, 100 g l−1 banana homogenate (BH), and 1.0 g l−1 AC was suitable for plantlet formation and 95.67% of plantlets developed from PLBs within 60 days of culture. Hyponex N016 medium supplemented with 0.5 mg l−1 NAA, 1.0 g l−1 peptone, 20 g l−1 sucrose, 150 g l−1 BH, and 1.0 g l−1 AC was suitable for the in vitro growth of plantlets about 2-cm in height. Plantlets 3-cm in height or taller were transplanted to Chilean sphagnum moss, and 95% of plantlets survived after 60 days in a greenhouse. Three hundred transplanted of seedlings 360-days old were reintroduced into three natural habitats. Highest percentage survival (79.67%) was observed in Yuanjiang Nature Reserve two years after reintroduction, followed by Huolu Mountain forest park (71.33%). This protocol is an efficient means for the large-scale propagation and in vitro and in vivo germplasm conservation of R. imschootiana.

Doubling the Chromosome Number of Black Poplar Trees (Populus nigra L.) by Colchicine In vitro

The possibility of inducing chromosomal polyploidy was studied for Black poplar (Populus nigra L.) which micropropagated from stem cutting by exposure to different colchicine concentrations 125, 250, 500 and 1000 mg / l and different exposure periods (0.0, 2, 4, 6, 8 days) in MS medium supplemented with 1mg/l BA and 0.3 mg/l IBA. After 4 weeks of exposure results showed the significant superiority of 125 mg / l colchicine treatment for stem cutting survival percentage transplant survival percentage after aclimitization and diploid plants percentage characteristics, also the results of polyploidy showed that the highest percentage of tetraploid plant (18%) was recorded for both treatments 125 and 250 mg/l colchicine, when 50.66% of plants treated with 500 mg/l colchicine has a mixed polyploidy and it was significantly different from the rest treatments. but the interaction effect of colchicine concentrations and exposure periods showed that the highest survival percentage was recorded for the treatments of non exposure and exposure to 125 mg/l colchicines for 2 days. After 16 weeks of aclimitization and field growing the results showed the significant superiority for both treatments of exposure with 125 and 250 mg/l colchicine for stem length, stem diameter, leaves number, vegetative system dry weight, stomata length, stomata width and total chlorophyll contents characteristics, this in comparison with 500 mg/l colchicine treatments, and this is in combined with finally the interaction effects of colchicine for the treatment of 250 mg/l colchicine for 2 days.