Kilson P. Lopes

Behavior of pomegranate (Punica granatum L.) seeds submitted the fermentation and drying

Sementes de roma (Punica granatum L.) foram submetidas a diferentes periodos de fermentacao (0; 24; 48; 72 e 96 horas), com e sem secagem. Avaliaram-se suas qualidades fisica e fisiologica, atraves das determinacoes do grau de umidade, peso de 100 sementes, porcentagem de emergencia e velocidade de emergencia de plântulas (IVE). O delineamento experimental adotado foi inteiramente casualizado, em esquema fatorial, onde os cinco periodos de fermentacao frente as duas condicoes (com e sem secagem) constituiram os tratamentos. Sementes submetidas ao maior periodo de fermentacao apresentaram sarcotestas mais degradadas, favorecendo, consequentemente, uma melhor absorcao de agua, resultando numa porcentagem de emergencia de 55% e IVE de 0,38, em 72 horas de fermentacao. A secagem das sementes apos fermentacao promoveu uma menor porcentagem de emergencia e IVE, apesar de se verificar um aumento de ambos, quando as sementes permaneceram em fermentacao por um maior periodo. O comportamento verificado nas sementes de roma frente aos tratamentos empregados parece estar associado a fenomenos de dormencia ou sensibilidade a secagem, caracteristica esta, de sementes recalcitrantes.

Criopreservação de eixos embrionários zigóticos de algodoeiro

The search for cultivars more adapted that assist the effective demand requires that the genetic resources of plant species are obtained easily. In order to evaluate a protocol for cryopreservation of embryonic axes of cotton, an experiment was carried out using seeds of the cultivars BRS 200 and BRS 201, which were extracted from embryonic axes and subjected to drying for 0, 30, 60 and 90 min and to the cryopreservation, directly plunged into liquid nitrogen (-196 °C), during 0, 5, 30 and 60 days. The regrowth of the embryonic axis was accomplished for each storage period, after its removal and thawing at room temperature conditions for 60 min, being cultivated in MS medium and kept in the incubator room at temperature of 25 °C, photoperiod of 16/8 h (light/dark) and light intensity of 30 /vmol m-2 s-1. After 30 days of cultivation, evaluations of the regeneration, seedling length and number of roots were accomplished. Embryonic axes of cotton, with moisture content around 9,7%, can be conserved in germoplasma banks in cryogenic conditions and to regenerate more than 80% of plantlets in vitro after 60 days of storage in liquid nitrogen (-196 °C).

Desempenho de sementes de sapoti (Achras sapota L.) submetidas a diferentes tratamentos pré-germinativos

O sapotizeiro (Achras sapota L.) e cultivado principalmente para a producao de frutos, encontrando-se entre os mais apreciados pela populacao das areas onde cresce. Sua propagacao pode dar-se atraves de enxertia ou diretamente por sementes, dando origem aos chamados pes-francos. Considerando o fato de que muitas das especies florestais e frutiferas apresentam o fenomeno de dormencia, e diante da necessidade de se intensificar estudos que melhor expliquem tal processo, o objetivo deste trabalho foi avaliar a eficiencia de diferentes tratamentos pre-germinativos em sementes de sapoti, visando a acelerar e uniformizar a germinacao de suas sementes. O ensaio foi conduzido em casa de vegetacao do Departamento de Fitotecnia, CCA/UFPB, Areia-PB, sendo utilizados os seguintes tratamentos: imersao em agua a 60°C por 1, 2 e 3 minutos; corte lateral (ao embriao) com e sem embebicao em agua por 24 horas; corte distal (ao embriao) com e sem embebicao em agua por 24 horas; corte lateral+distal (ao embriao) com e sem embebicao em agua por 24 horas e a testemunha (ausencia de tratamento). Efetuados os tratamentos, foi realizada a semeadura em bandejas contendo areia lavada e autoclavada, utilizando-se de quatro repeticoes de 25 sementes. As caracteristicas avaliadas foram: percentagem e indice de velocidade de emergencia, comprimento de raiz e de hipocotilo e peso de materia seca de planta. O delineamento experimental foi o Inteiramente Casualizado, e os contrastes entre as medias foram realizados atraves do teste de Duncan, ao nivel de 5% de probabilidade. As sementes de sapoti exibiram maior emergencia (81%) e indice de velocidade de emergencia (0,58) quando submetidas ao corte lateral, sem embebicao. O corte das sementes seguido de embebicao por 24 horas nao foi eficiente para acelerar a emergencia e o indice de velocidade de emergencia de plântulas de sapoti. A imersao em agua a 60°C, independentemente do tempo utilizado, nao deve ser recomendada como tratamento pre-germinativo para sementes de sapoti.

Crioconservação de sementes de algodão

The objective of this work was to evaluate the crioconservation of cotton seed. At first, the water limit content for the crioconservation (TALC) was determined. For this determination, the seeds were immerse in liquid nitrogen during five days and after this period they were unfrozen and submitted to germination and vigor test. The statistical design used was completely randomized with the factorial. A portion of seeds was used with water limit content previously determinated for the different cultivars, since this has proceeded the storage in liquid nitrogen and in nitrogen vapor. The experimental design used in this stage was completely randomized in subdivided plots over time. In each period of storage the seeds were submitted to germination and vigor tests. According to the obtained results, it was concluded that: (a) the water content limit for crioconservation (TALC), during 5 days, for the conservation of four cultivars, considering the germination of these cultivars, is between 6 and 8% and, as to the seed vigor, the TALC was 6%; (b) the seeds of the different cultivars can be crioconserved in germoplasma bank at two temperatures; (c) the crioconservation increases the percentage of germination and the vigor of the cotton seeds, due to this temperature promoting termination of dormancy by the action of cold.The objective of this work was to evaluate the crioconservation of cotton seed. At first, the water limit content for the crioconservation (TALC) was determined. For this determination, the seeds were immerse in liquid nitrogen during five days and after this period they were unfrozen and submitted to germination and vigor test. The statistical design used was completely randomized with the factorial. A portion of seeds was used with water limit content previously determinated for the different cultivars, since this has proceeded the storage in liquid nitrogen and in nitrogen vapor. The experimental design used in this stage was completely randomized in subdivided plots over time. In each period of storage the seeds were submitted to germination and vigor tests. According to the obtained results, it was concluded that: (a) the water content limit for crioconservation (TALC), during 5 days, for the conservation of four cultivars, considering the germination of these cultivars, is between 6 and 8% and, as to the seed vigor, the TALC was 6%; (b) the seeds of the different cultivars can be crioconserved in germoplasma bank at two temperatures; (c) the crioconservation increases the percentage of germination and the vigor of the cotton seeds, due to this temperature promoting termination of dormancy by the action of cold.

Semillas de Spondias tuberosa oriundas de frutos cosechados en cuatro estadios de maduración y almacenadas

The peculiar climatic conditions of the semi-arid area offer plants for the human exploration in natural a way among these, stands out the Spondias tuberosa Arruda Câmara, whose fruit is havested in an extractive and disorganized way, putting in risk its perpetuation. The objective of this study was to verify the storage period of the seeds, the environments and the stage of fruit maturation most adopted to a good propagation of the species. The experiment was conduted in a greenhouse at the Center of Agricultural Sciences, (CCA), Areia, UFPB, PB. The experimental design used was a completely randomized in a factorial scheme (5 x 2 x 4), with four repetitions. The studied variables were the germination percentage, vigour (index of germination speed), number of sprouts, height of plants, diameter and length of the tubers. The seeds maintained under natural environmental conditions, stored for a period of eight months presented higher germination uniformity, germinative potential of 90%, and vigour of 0,505. The most appropriate seeds to optimise germination were those originating from the mature fruits (87,5%) and highly ripened fruits (90%).

Efeito do beneficiamento na qualidade fisiológica e sanitária de sementes do algodoeiro herbáceo

Seeds of cotton cvs. CNPA Precoce 2 and CNPA 7H, produced under irrigated conditions in Touros Rio Grande do Norte State Brazil during the 1998/99 growing season were submitted to deseeding, mechanical or chemical delintering and then, packed in multi-layered paper bags and stored in a dry chamber or under room conditions during 360 days. Every 90 days, data on physiological and sanitary conditions of seeds were collected. The split plot design was employed, with four replications for each whole plot treatment arranged according to a completely randomized design. Collected data were analyzed by variance analysis and polynomial regression techniques. Chemically delinted seeds from both varieties, stored in dry chamber, preserved their physiological qualities until 270 days of storage. cv. CNPA Precoce 2 deseeded or mechanically delinted seeds kept better their physiological and sanitary conditions when stored in dry chamber. The same occurred for cv. CNPA 7H seeds when stored under room conditions. Seed mycoflora was constituted by Aspergillus.

Indução de superbrotamento e regeneração de plantas in vitro, nas cultivares de algodão colorido

The micropropagation in vitro has been presented as a technique that allows various methodologies which, for in turn, contribute to a reduction in the time to obtain new cultivares. The objective of this work was to evaluate the behavior of the genotypes BRS-Verde, BRS-200-Marrom, 6M-Moco-white and BRs-187-8H- white, in the induction of the multiple shoots in different combinations of growth regulators. The seeds, to obtain the initial material, were placed in a solution of 1% sodium hypochlorite of active chlorine for 20 min. The shoot had been induced, in the explant of cotiledonary nodes in MS medium basic, supplemented with 6-benzylaminopurine (BAP), Cinetina (KIN) and Tiadiazuron (TDZ), isolated or associated in different concentrations. The material was kept for 40 days in growth chamber, under controlled ambient conditions. 10 mL of medium was used for treatment with a explant for culture tube, in an entirely randomized design, with factorial arrangement of 4 x 17 (four genotypes x seventeen medium). It was observed that the MS medium supplemented with BAP (2.0 mg L-1) isolated or associated with KIN (1.0 mg L-1), promoted greater capacity of regeneration and height of sprouts; MS medium supplemented with BAP (2.5 mg L-1) stimulated greater height of sprouts and the MS medium supplemented with TDZ (1.0, 0.50 and 0.25 mg L-1) affected the capacity of regeneration of sprouts, a larger formation of calluses was observed.

Crioconservation of cotton seed

The objective of this work was to evaluate the crioconservation of cotton seed. At first, the water limit content for the crioconservation (TALC) was determined. For this determination, the seeds were immerse in liquid nitrogen during five days and after this period they were unfrozen and submitted to germination and vigor test. The statistical design used was completely randomized with the factorial. A portion of seeds was used with water limit content previously determinated for the different cultivars, since this has proceeded the storage in liquid nitrogen and in nitrogen vapor. The experimental design used in this stage was completely randomized in subdivided plots over time. In each period of storage the seeds were submitted to germination and vigor tests. According to the obtained results, it was concluded that: (a) the water content limit for crioconservation (TALC), during 5 days, for the conservation of four cultivars, considering the germination of these cultivars, is between 6 and 8% and, as to the seed vigor, the TALC was 6%; (b) the seeds of the different cultivars can be crioconserved in germoplasma bank at two temperatures; (c) the crioconservation increases the percentage of germination and the vigor of the cotton seeds, due to this temperature promoting termination of dormancy by the action of cold.The objective of this work was to evaluate the crioconservation of cotton seed. At first, the water limit content for the crioconservation (TALC) was determined. For this determination, the seeds were immerse in liquid nitrogen during five days and after this period they were unfrozen and submitted to germination and vigor test. The statistical design used was completely randomized with the factorial. A portion of seeds was used with water limit content previously determinated for the different cultivars, since this has proceeded the storage in liquid nitrogen and in nitrogen vapor. The experimental design used in this stage was completely randomized in subdivided plots over time. In each period of storage the seeds were submitted to germination and vigor tests. According to the obtained results, it was concluded that: (a) the water content limit for crioconservation (TALC), during 5 days, for the conservation of four cultivars, considering the germination of these cultivars, is between 6 and 8% and, as to the seed vigor, the TALC was 6%; (b) the seeds of the different cultivars can be crioconserved in germoplasma bank at two temperatures; (c) the crioconservation increases the percentage of germination and the vigor of the cotton seeds, due to this temperature promoting termination of dormancy by the action of cold.

Cryoconservation of cotton seed.

The objective of this work was to evaluate the crioconservation of cotton seed. At first, the water limit content for the crioconservation (TALC) was determined. For this determination, the seeds were immerse in liquid nitrogen during five days and after this period they were unfrozen and submitted to germination and vigor test. The statistical design used was completely randomized with the factorial. A portion of seeds was used with water limit content previously determinated for the different cultivars, since this has proceeded the storage in liquid nitrogen and in nitrogen vapor. The experimental design used in this stage was completely randomized in subdivided plots over time. In each period of storage the seeds were submitted to germination and vigor tests. According to the obtained results, it was concluded that: (a) the water content limit for crioconservation (TALC), during 5 days, for the conservation of four cultivars, considering the germination of these cultivars, is between 6 and 8% and, as to the seed vigor, the TALC was 6%; (b) the seeds of the different cultivars can be crioconserved in germoplasma bank at two temperatures; (c) the crioconservation increases the percentage of germination and the vigor of the cotton seeds, due to this temperature promoting termination of dormancy by the action of cold.The objective of this work was to evaluate the crioconservation of cotton seed. At first, the water limit content for the crioconservation (TALC) was determined. For this determination, the seeds were immerse in liquid nitrogen during five days and after this period they were unfrozen and submitted to germination and vigor test. The statistical design used was completely randomized with the factorial. A portion of seeds was used with water limit content previously determinated for the different cultivars, since this has proceeded the storage in liquid nitrogen and in nitrogen vapor. The experimental design used in this stage was completely randomized in subdivided plots over time. In each period of storage the seeds were submitted to germination and vigor tests. According to the obtained results, it was concluded that: (a) the water content limit for crioconservation (TALC), during 5 days, for the conservation of four cultivars, considering the germination of these cultivars, is between 6 and 8% and, as to the seed vigor, the TALC was 6%; (b) the seeds of the different cultivars can be crioconserved in germoplasma bank at two temperatures; (c) the crioconservation increases the percentage of germination and the vigor of the cotton seeds, due to this temperature promoting termination of dormancy by the action of cold.