Jonny Everson Scherwinski Pereira

Germinação in vitro de embriões zigóticos de murmuru (Astrocaryum ulei)

Com o presente trabalho objetivou-se avaliar a influencia de concentracoes de sacarose e a idade fisiologica da semente na germinacao in vitro de embrioes zigoticos de murmuru. Frutos em dois estagios de desenvolvimento coletados de plantas do campo tiveram os embrioes excisados, desinfestados e inoculados em meio de cultura de MS com 75% das concentracoes de sais, suplementado com 2,5 g.L-1 de acido giberelico e diferentes concentracoes de sacarose: 15, 30 e 45 g.L-1. Em sala de crescimento, o material foi mantido por 30 dias no escuro, sendo transferido em seguida para condicoes luminosas de 30 me.m-2.s-1, temperatura de 25±2oC e fotoperiodo de 16 horas para completo desenvolvimento. O delineamento estatistico utilizado foi inteiramente casualizado em arranjo fatorial 2 x 3, com seis repeticoes e cinco embrioes por parcela. Apos 30 dias foi avaliada a porcentagem de germinacao e altura das plântulas. Verificou-se que embrioes provenientes de frutos imaturos apresentaram maior porcentagem de germinacao, sendo a concentracao de 30 g.L-1 de sacarosea que proporcionou os melhores resultados dentre as demais testadas. Embrioes provenientes de frutos maduros apresentaram altura de plântulas significativamente maior aos imaturos e tambem para essa variavel, a concentracao de 30 g.L-1 de sacarose foi a que proporcionou os melhores resultados.

Protocolo para produção de material propagativo de batata em meio líquido

Abstract – Semi-solid media are more commonly used in studies of micropropagation, but the physicalstate of the culture media seems to influence the growth and multiplication rate of the cultivation. Theobjective of this work was to establish a protocol for in vitro multiplication of potato in liquid culturemedia. Potato explants, cultivar Eliza, with an axillary bud, were cultivated in six different culturemedia, with (semi-solid) or without (liquid) the addition of agar. After 21 days, the culture medium thatprovided the best results for growth and multiplication rate had the composition modified with theobjective of improving the efficiency of in vitro multiplication of five cultivars in liquid medium. Theneed of agitation was also evaluated in liquid culture medium. There was high efficiency of the in vitropotato multiplication when it was cultivated in liquid medium. The MS salt medium in the full concen-tration, added by gibberellic acid (0.25 mg L -1 ), panthotenic acid (5.0 mg L ), thiamine (1.0 mg L

Identificação e controle com antibióticos de bactérias endofíticas contaminantes em explantes de batata micropropagados

This work aimed to isolate, characterize and identify contaminant endophytic bacteria found in potato tissues during the micropropagation and to select antibiotics for in vitro control of these microorganisms by determining the inhibitory minimal bactericidal concentration. Potato shoots pre- senting bacterial contamination during the in vitro multiplication were superficially sterilized and the internodes transferred to Petri dishes with nutrient agar medium for up to five days at 28°C. After subcultures the grown bacteria were purified and identified through taxonomic tests. A total of eight bacterial endophytic strains were isolated and identified as belonging to Acetobacteriaceae (1) and Enterobacteriaceae (2) families and Corynebacterium (3), Pseudomonas (1) and Xanthomonas (1) genera. The best results for bacterial growth inhibition were obtained with ampicilin, chlorampheni- col, streptomycin and tetracycline antibiotics in concentrations ranging from 32 to 256 mg L -1 .

Efeito de agentes geleificantes alternativos no meio de cultura no cultivo in vitro de abacaxizeiro e bananeira

Com este trabalho, objetivou-se avaliar a acao do agar e sua substituicao parcial e total pelo amido de mandioca na composicao de meios de cultura de bananeira e abacaxizeiro. Gemas axilares de abacaxizeiro, cvs. Rio Branco e Quinari foram estabelecidas e avaliadas por quatro subcultivos quanto a multiplicacao em meio de MS, suplementado com 2 mg.L-1 de BAP e 0,25 mg.L-1 de ANA, e os seguintes tratamentos: M1: agar (5 g.L-1), M2: agar (2,5 g.L-1) + fecula de mandioca (60 g.L-1), M3: fecula de mandioca (60 g.L-1), e M4: agar (2,5 g.L-1) + fecula de mandioca (30 g.L-1). Num segundo experimento, por tres subcultivos sucessivos brotacoes de bananeira da cv. Grand Naine foram avaliadas quanto a multiplicacao em meio de cultura composto por: MM1: agar (6 g.L-1) ; MM2: agar (3 g.L-1) + fecula de mandioca (30 g.L-1); MM3: fecula de mandioca (60 g.L-1) e; MM4: meio de consistencia liquida estacionario.Estes meios foram suplementados com 0, 2, 4 e 6 mg.L-1 de BAP. Para o abacaxizeiro, verificou-se quea substituicao total do agar pela fecula proporcionou resultados similares aos obtidos com o tratamento com agar. Na combinacao agar + fecula os resultados foram inferiores aos obtidos com os solidificantes usados isoladamente. Para a bananeira, o uso isolado ou combinado da fecula com agar nao proporcionou melhora nas taxas de multiplicacao. Os melhores resultados foram obtidos em meio com agar e 2 mg.L-1 de BAP. O cultivo em meio liquido apresentou o menor indice de multiplicacao.

AVALIAÇÃO DE METODOLOGIA ALTERNATIVA PARA O TESTE DE TETRAZÓLIO PARA SEMENTES DE SOJA

An alternative method of the tetrazolium test established that the preconditioning period of soybean seeds could be successfully shortened from the traditionally 16 hours at 25oC to 6 hours at 41oC. Since this alternative method has been tested so far with a limited number of soybean cultivars, it is imperative that it should be tested for additional cultivars. The applicability of this alternative procedure of seed preconditioning was tested in ten soybean cultivars: BR-13, EMBRAPA 4, EMBRAPA 48, FT-Abyara, FT-5, IAS 5, OCEPAR-13, OCEPAR-14, OCEPAR-16, and OCEPAR-17. Two imbibition periods (4 h and 6 h) at 41oC were tested and compared to the traditionally recommended period for preconditioning. The following tests were carried out: seed moisture content and tetrazolium through determinations of vigor, viability and level of mechanical damage, weathering and sting bug damage. From the results, the following conclusions can be drawn: a) seed preconditioninig for 6h at 41oC resulted in adequate staining patterns of the seeds, allowing accurate estimates of vigor and viability; b) seed preconditioning for 4 h at 41°C did not develop adequate staining of the seeds, to correctly evaluate vigor and viability of the seeds; however, this procedure was efficient to identify sting bug damage on seeds.

Efeito da interação entre carvão ativado e N6-benzilaminopurina na propagação in vitro de bananeira, cv. Grand Naine (AAA)

O carvao ativado possui a propriedade de adsorver os compostos fenolicos liberados pela oxidacao dos tecidos lesionados durante o cultivo in vitro. O objetivo deste trabalho foi avaliar os efeitos da interacao entre o carvao ativado e diferentes concentracoes de N6-benzilaminopurina (BAP) na multiplicacao in vitro da bananeira, cv. Grande Naine (AAA). O meio de cultura utilizado foi o MS, solidificado com 5 g.L-1 de agar. O cultivo foi mantido em sala de crescimento a 25±2oC, fotoperiodo de 16 horas e intensidade luminosa de 30 mmol.m-2s-1. Foram avaliadas a presenca e a ausencia de carvao ativado (0 e 3 g.L-1) e quatro concentracoes de BAP (0; 2; 4 e 6 mg.L-1) no meio de cultura. O delineamento foi inteiramente casualizado, com cinco repeticoes, em um sistema fatorial 2x4. Os explantes foram avaliados a cada 30 dias, por um periodo de quatro subcultivos. Apos cada subcultivo, o comprimento de brotacoes, a taxa de multiplicacao, o vigor, o nivel de oxidacao das brotacoes emitidas e o numero de raizes formadas foram avaliados. Independentemente das concentracoes de BAP, o carvao ativado influenciou significativamente em todas as variaveis analisadas. De maneira geral, a adicao de carvao ativado afetou negativamente a taxa de multiplicacao, embora tenha melhorado o vigor e o numero de raizes e diminuido a oxidacao dos explantes. Na ausencia de carvao ativado, o BAP proporcionou as maiores taxas de multiplicacao das brotacoes.

Produção de mudas pré-básicas de batata por estaquia a partir de plantas micropropagadas

The use of cuttings from micropropagated potato plants can become an efficient technique to improve the multiplication rate of potato genotypes of high genetic quality and sanitary level. A protocol for the production of pre-basic potato material by microcuttings, obtained from plants with a short period of acclimatization, was established. The influence of cutting position (basal, medium and apical), the collection period (15 and 30 days), the immersion time (zero and one minute) in different IBA concentrations (0; 250; 500; 750 and 1000 mg L-1), and substrate types (sand and vermiculite) were analyzed in two experiments. Basal, medium and apical microcutting position presented rooting rates up to 90% when collected from 15 days acclimatization potato plants followed by treatment through fast immersion in IBA solution at 500 mg L-1 and in sand or vermiculite as substrate.

Crescimento de mudas micropropagadas de bananeira aclimatizadas nas condições da Amazônia Sul Ocidental sob a influência de diferentes substratos e recipientes

For laboratories that produce thousands of micropropagated plants regularly, the optimization of the acclimatization phase is of fundamental importance to avoid excessive losses and to promote the development of the plants. The aim of this work was to evaluate the growth of micropropagated banana plantlets during the acclimatization under the influence of different substrates and recipients on conditions of South West Amazon. Shoots of banana, cv. Grand Naine, were rooted in MS medium, being the rooting plants transferred to a nursery, in two types of plastic dibble tubes (115 cm3 and 180 cm3) and six different substrates formulated from different portions of soil, carbonized rice hulls and bovine manure. Evaluations of plant survival, height of the aerial part and pseudostem diameter were carried out each fifteen days, and at the end of 75 days, fresh and dry mass for the roots and aerial parts of the plants were also determined. It was verified that the plant survival was not influenced by the use of the 115 cm3 or 180 cm3 plastic dibble tubes. However, acclimatization accomplished in the 180 cm3 plastic dibble tubes provided larger growth in height and pseudostem diameter of the plants and, consequently, larger accumulation of fresh and dry mass of roots and aerial parts, when compared to the 115 cm3 plastic dibble tubes. Among the substrates, it was observed that bovine manure was fundamental as substrate component to obtain the best results.

Relação entre o tempo de enraizamento in vitro e o crescimento de plantas de bananeira na aclimatização

The objective of the present study was to assess the influence of the exposition time to rooting medium on the in vitro and ex vitro growth of banana plants. As explants, new axillaries buds obtained from the in vitro establishment and multiplication of stem apices of Caipira (AAA), Preciosa (AAAB) and Japira (AAAB) cultivars were used. The MS medium with reduction to 50% of the salt concentration adding 30 g.L-1 of sucrose, 1 mg.L-1 of IBA, and 6 g.L-1 of agar was used to induce rooting. The treatments were analyzed in a 3x4 factorial design, with three cultivars (Caipira, Preciosa and Japira) and four in vitro rooting periods (7, 14, 21 and 28 days), given a total of 12 treatments. At the end of each period, the height of the aerial portion, and number and length of roots were assessed, and the plants were submitted to 90 days of acclimatization. After that, the survival, number and length of roots, pseudostem diameter, and dry weight of the roots, aerial and total portions of the plants were assessed. Generally, the root induction step in the in vitro banana budding occurred up to 14 days of cultivation in rooting medium, and after that, the roots grew only in length. Among the cultivars, it was verified that, with the exception of the pseudostem diameter, the Caipira cultivar showed superior in vitro vegetative growth, and during the acclimatization, the height of the plant, number and length of the roots, and dry mass of the aerial, roots, and total parts, were also superior to the observed in Preciosa and Japira cultivars. After 21 days on rooting medium, the survival rate of the plants in greenhouse reach 100%, in despite of the tested cultivar.

Perda de água e modificações anatômicas em folhas de plantas de bananeiras micropropagadas durante a aclimatização

Studies concerning factors involved in the adaptation of micropropagated plants to ex vitro conditions are indispensable to define which procedures should be used during the acclimatization phase. The objective of this research was to evaluate the presence of stomata and epicuticular wax on water loss control in micropropagated banana plants. For 24 days axillary buds were rooted in MS medium supplemented with NAA (1mg L-1) and agar (6g L-1), and afterwards the plantlets were acclimatized for 120 days. The treatments consisted of the evaluation of in vitro leaves and at different acclimatization stages, as follows: T1 - leaves of plants at the end of the in vitro rooting phase T2 - persistent leaves of plants after 30 days of acclimatization; T3 - new leaves from plants after 30 days of acclimatization (transition leaves); T4 - transition leaves from plants after 60 days of acclimatization; T5 and T6 - new leaves from plants after 60 and 120 days of acclimatization, respectively. Data regarding stomatal density, relative water content and presence of epicuticular wax were also evaluated. It was verified that new leaves from plants rooted in vitro under mixotrophic condition presented hight stomatal density and hence a reduced control of water loss. The reduced transpiration of leaves formed during the acclimatization phase can be attributed to the small number of stomata per unit of leaf area associated to the largest capacity of these in restricting water loss, and the presence of epicuticular wax.