RESUMOA pitaia vermelha de polpa branca (Hilocereus undatus) é uma cactácea, pertencente ao grupo das frutíferas tropicais, considerada promissora para o cultivo. Objetivou-se induzir calos e determinar o potencial embriogênico e a estabilidade genética em pitaia. ); 2 a ) Curva de crescimento de calos, por vários períodos de tempo (0, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105 Callus induction, embryogenic potential and genetic stability in red pitaya ABSTRACTThe red pitaya with white pulp (Hilocereus undatus) is a cactus belonging to the group of tropical fruit, considered promising for cultivation. This study aims to induce callus and embryogenic potential and determine the genetic stability in pitaya. The study was divided into four steps: 1ª) Callus induction using doses of 2,4-D (2.0 and 4.0 mg L -1 ) and with doses of glutamine (100 and 200 mg L -1 ); 2ª) callus growth curve for various time periods (0, 7, 14, 21 , 28, 35, 42 , 49, 56, 63 , 70, 77, 84 , 91, 98, 105 and 112 days); 3ª) Cytochemical analysis to assess the potential of embryogenic callus (samples consisting of 100 mg of callus) and 4ª) Analysis of flow cytometry to assess the genetic stability of the callus (compared with a seedling in vitro -control). The conclusion is that the 4.0 mg L -1 2,4-D is the best concentration for callus induction in explants shoots of pitaya; the glutamine does not influence the callus formation. The callus has higher embryogenic potential at 49 days, therefore must be spiked in this period. By flow cytometric was detected endoreduplication in the material analyzed.

Due to the non-uninform maturation of tobacco fruits and seeds, the priming technique has been used by the tobacco industry as a way of increasing the uniformity and germinations peed of seeds. Several factors can affect priming, including the time and environment in which the treatment is performed. In order to evaluate the effect of sodium hypochlorite as priming agent at different concentrations and the priming period on the physiological quality of the tobacco seeds, it was used a seed lot of commercial cultivar CSC 439 from the Virginia varietal group, widely used by the producing companies. The seeds were subjected to priming in aerated solution at different priming periods (180, 60, 30, 15, and 5 min) and concentrations of sodium hypochlorite (1%, 0.50%, 0.25%, and 0.10 %). The physiological quality was evaluated by the water contents, germination tests, first count, germination index, initial and final stands, emergence index and electrical conductivity. The priming with sodium hypochlorite did not affect germination, but allowed a higher percentage and speed of emergence when using the 1% concentration for 180, 30 and 15 min.

Priming is a commercial technique used to increase the speed and uniformity of seed germination. However, the physiological quality of primed seeds is usually negatively affected during storage. Tobacco seeds of the cultivar BAT 2101 were used to investigate whether primed seeds could be cryopreserved. The most suitable substances, type of drying, and reheating during priming and cryopreservation of tobacco seeds were studied. Seed priming was performed with water, spermidine, and potassium nitrate, and drying was carried out with silica gel and a saturated saline solution. Seeds were cryopreserved in liquid nitrogen for 24 h and reheated in a water bath for two and five minutes and at ambient temperature. Tobacco seeds primed with spermidine and water can be cryopreserved without loss of physiological quality when quickly dried on silica gel and reheated in a water bath for two minutes.

ResumoImportância das amilases na qualidade isiológica de sementes de milho. A qualidade de sementes está associada à soma dos atributos genéticos, físicos, isiológicos e sanitários que afetam sua capacidade para realizar as funções vitais, estando relacionada à germinação, ao vigor e à longevidade. A expressão de genes associados à qualidade isiológica pode ser avaliada por meio de análises de germinação e vigor, e ainda pelas análises de transcritos e de proteínas em sementes. Objetivou-se com este trabalho fazer uma revisão sobre a relevância das enzimas do grupo das amilases relacionadas à qualidade isiológica de sementes de milho. Dentro do grupo das amilases, a α-amilase (1,4-α-D-glucan-glucanohydrolase, E.C 3.2.1.1) é uma enzima importante na hidrólise do amido, sendo responsável por 90% da atividade amilolítica em sementes de milho. Essa enzima, a exemplo da dextrose, causa a conversão de amido em açúcares que são utilizados no crescimento do embrião. Já a β-amilase (1,4-α-D-glucan maltohydrolase, E.C 3.2.1.2) catalisa a liberação de maltose e dextrinas a partir das extremidades não redutoras do amido. Pesquisas comprovam que as enzimas amilases estão ligadas diretamente à qualidade isiológica de sementes de milho. A α-amilase e a β-amilase estão envolvidas principalmente no processo de germinação e na heterose das sementes, podendo ser também utilizadas como marcadores moleculares relacionadas à tolerância de secagem das sementes.Palavras-chave: α-amilase; β-amilase; Germinação; Heterose; Marcador molecular AbstractSeed quality is the result of the sum of genetic, physical, physiological and sanitary attributes that affect seed ability to perform vital functions related to germination, vigor, and longevity. The expression of genes associated with physiological quality can be assessed by means of germination and vigor analyses, as well as by transcript and protein analyses. The objective in this work was to review the relevance of amylase group enzymes to the physiological quality of maize seeds. Within this group, α-amylase (1,4-α-D-glucan glucanohydrolase E.C 3.2.1.1) plays an important role in starch hydrolysis, and is responsible for 90% of the amylolytic activity in maize seeds. It is responsible for starch conversion into sugars (e.g., destrin), which is used for embryo growth. β-amylase (1,4-α-D-glucan maltohydrolase E.C 3.2.1.2) catalyzes the release of maltose and dextrins from the non-reducing ends of starch. Research has shown that amylase enzymes are directly linked to physiological quality of maize seeds. Alpha-and beta-amylases are mainly involved in the germination process and seed heterosis, and can also be used as molecular markers associated with seed tolerance for drying.

ABSTRACT. Evaluation of the physiological potential of maize seeds during the certification process is performed by a germination test. However, some tests show a delay in the growth of aerial seedling organs that does not reflect seed lot behavior in the field. This study aims to investigate the effects of genotype, water, light and temperature on differential primary leaf growth compared to coleoptile length in maize seedlings. Seeds from two simple hybrids and their reciprocal crosses that showed slow primary leaf growth were evaluated according to physiological quality, morphology, histochemistry, and enzymatic expression. There were differences among maize genotypes regarding initial primary leaf growth when compared to the coleoptile, especially when germination was tested without light. Water availability and optimal temperature range did not affect the differential growth of the primary leaf in the hybrids. Pericarp thickness, lignin content and differences in enzyme expression in different genotypes were also not related to changes in the relationship of primary leaf growth with coleoptile length during the maize seed germination test.Keywords: Zea mays L.; germination test; lignin; enzymes.Crescimento diferencial da plúmula e do comprimento do coleóptilo de plântulas de milho RESUMO. A avaliação do potencial fisiológico de lotes de sementes de milho no processo de certificação é realizada pelo teste de germinação. No entanto, em alguns testes, são observados atrasos no crescimento das estruturas da parte aérea das plântulas, o que leva a considerá-las plântulas anormais, mas não reflete o comportamento do lote no campo. Objetivou-se, neste trabalho, investigar o efeito do genótipo, água, luz e temperatura sobre o crescimento diferencial da plúmula em relação ao comprimento do coleóptilo de plântulas de milho. Sementes de dois híbridos simples e dos seus recíprocos com característica de crescimento lento da plúmula, foram avaliadas em sua qualidade fisiológica, morfológica, histoquímica e expressão enzimática. Existem diferenças entre genótipos de milho no que se refere ao crescimento inicial da plúmula em relação ao coleóptilo, principalmente na ausência de luz no teste de germinação. Disponibilidade hídrica e temperatura não afetam a resposta dos híbridos em relação ao crescimento diferencial da plúmula. Espessura do pericarpo, presença de lignina ou diferenças na expressão das enzimas dos genótipos não estão relacionadas às variações de comprimento plúmula/coleóptilo, durante o teste de germinação.Palavras-chave: Zea mays L.; teste de germinação; lignina; enzimas.

The packaging, used to maintain the seeds during storage, is extremely important in their conservation. Seeds from the cultivar BAT 2101 were used in order to evaluate the effect of packaging on the conservation of the quality of bare and pelleted tobacco seeds stored in the long-term. After characterization of the lot profile, the seeds were stored for 180, 360, 540, and 720 days under ambient conditions at 25 °C ± 2 and 62.8% relative humidity in cotton bags, aluminum cans, laminated envelopes, plastic envelopes and paper envelopes. The seed quality throughout the storage in the different packages was determined by the water content and germination tests, first germination count, germination speed index, initial and final emergence and emergence speed index. The aluminum can packaging keeps the quality of bare and pelleted tobacco seeds for a period of 720 days. Up to 360 days of storage, there was a decrease in the dormancy of bare and pelleted seeds with an increase in deterioration after this period, except for those kept in the aluminum can packing.

O objetivo deste estudo foi de avaliar a atividade antifúngica de uma solução à base de glucoprotamina(GLU) e de óleo essencial (OE) de Cymbopogon citratus. Candida tropicalis, Claviceps lusitaniae,Meyerozyma (Pichia) guilliermondii e Candida parapsilosis foram isoladas das superfícies de umhospital público de Pelotas, RS. A atividade antifúngica da GLU foi analisada nas concentrações de0,25% a 0,0005%, e para o OE, obtido por Clevenger, foi utilizado nas concentrações de 17.500 μg/mLa 0,034 μg/mL. A análise cromatográfica foi efetuada por meio de CG/MS. A atividade anti-Candidafoi analisada pela técnica de Microdiluição em Caldo para determinar a Concentração InibitóriaMínima (CIM) e a Concentração Fungicida Mínima (CFM). A inibição pela GLU ocorreu emtodas as concentrações testadas, enquanto o OE apresentou resultado de CIM que oscilou de 2846 a5450 μg/mL, e CFM de 2853 a 5330 μg/mL. Alfa–citral (37,10%), beta–citral (32,77% e beta-mirceno(18,75%) foram considerados como os compostos majoritários do OE. Os dados obtidos nestetrabalho destacam a atividade antifúngica da solução à base de GLU e do OE de C. citratus naeliminação dos isolados de Candida spp ambientais.

The objective of this work was to evaluate the effects of different storage conditions on the physiological and sanitary quality and oil content of castor bean (Ricinus communis) seeds. Seeds of castor bean plants of the Guarani, and IAC-80 cultivars were stored in two environments (cold room, and room conditions), using three package types (multifoliate Kraft paper bag, and polyethylene bag, and polyethylene bag with vacuum at 1 atm). In addition, another storage condition was evaluated: cryopreservation (-196 °C) in foil paper bags. Seed quality was evaluated before storage and at 4, 8, and 12 months after storage by testing their 7-day and 14-day germination, emergence, health, water content, and oil content. The experiment was conducted in a completely randomized design, with 7×4 factorial arrangement consisting of seven storage conditions and four evaluation times. Cryopreservation is the ideal condition for maintaining the seed physiological quality of the Ricinus communis cultivars used throughout storage. The oil content of the R. communis seeds decreases, and the incidence of Aspergillus spp. and Fusarium spp. fungi increases throughout storage, regardless of the storage conditions.