ABSTRACT This study aimed to characterize the occurrence, duration, and intensity of the flushes of vegetative growth in two peach cultivars of Prunus persica L. Batsch, grown as a pioneer endeavor at a high-altitude tropical climate site in the State of Minas Gerais, Brazil. The observational experiment was carried out in 2017/18 and 2018/19 on the ‘Tropic Beauty’ and ‘BRS Kampai’ cultivars by an evaluation of the number and duration of flushes of vegetative growth during the year over two cycles. The number of fruit-bearing shoots, total number of leaves and shoot length were also assessed. At harvest, fruit load and diameter were determined and grouped into diameter ranges. The number of hours recorded at different temperature ranges, < 10.0 °C; 10.1-15.0 °C; 15.1-20.0 °C; 20.1-25.0 °C; > 25.1 °C, were summed separately and divided into daily and nightly periods. The peach tree has an unusual vegetative growth pattern when cultivated in a tropical area, which occurs in two flushes, with the first flush occurring from budbreak to fruit harvest between June and Sept, forming short shoots (less than 10 cm), with early shoot growth cessation, with a limited leaf number that can potentially diminish the supply of carbohydrates to the fruit, leading to smaller growth. The second flush occurs after harvest, between Oct and Dec, when there is an increase in daily temperature and precipitation, and no competition with fruits. Notabily, these second flush shoots grow with greater vigor and regularization of the growth cycle, forming fruit-bearing shoots with abundant leaf and flower buds for the next production cycle.

ABSTRACT. Excoriation damage is among the major causes of postharvest potato losses. Curing is known to increase the resistance of tubers to excoriation injury, with the temperature influencing the traumatic phellogen and periderm regeneration, as well as tuber processing quality. This study aimed to evaluate the effects of excoriation procedure and curing temperature on the industrial quality, histological characteristics, carbohydrate metabolism, and oxidative enzyme activity of potato tuber. Tubers with or without excoriation were cured at 8, 14, and 20°C for 15 days. Excoriation did not influence the levels of reducing sugars (RS), as well as polyphenoloxidase (PPO) and peroxidase (POD) activities. The concentrations of total soluble sugars (TSS) and non-reducing sugars (NRS) were higher in injured tubers, while reduction in curing temperature increased the concentrations of TSS, NRS, and RS. However, the sugar content was adequate as per the criteria of the pre-fried potato industry and potatoes classified in category 2 (USDA/fast-food industry color grading). The reduction in curing temperature also increased the activity of POD, despite the activity of PPO remaining unchanged. Formation of a closure layer from the outer parenchyma cells of the tuber that prevents desiccation and death of superficial cells, was observed. This protection was completed with the formation of the damage periderm. Periderm regeneration is faster at higher temperatures, 15 and 20°C, leading to a lower fresh mass loss and no enzymatic or non-enzymatic browning. The excoriation carried out at 14/20oC for 15 days was sufficient for curing, and for maintaining suitable post-fry quality of potatoes.

RESUMO O estádio de maturação das sementes influencia a sua qualidade fisiológica logo após a colheita. O objetivo do trabalho foi avaliar as alterações anatômicas, histoquímicas e fisiológicas em sementes de grão-de-bico ‘BRS Aleppo’ obtidas de vagens em diferentes estádios de maturação. Foram colhidas vagens em cinco estádios de maturação: verde, verde-amarelo, amarelo, amarelo-dourado e marrom. Para caracterização anatômica e histoquímica os cortes foram corados com Azul de Toluidina, Lugol, Xylidine Ponceau (XP), Vermelho de Rutênio. Para avaliação das alterações fisiológicas, as sementes foram secas até 12% de umidade. Foram realizados os seguintes testes: grau de umidade, germinação, porcentagem e índice de velocidade de emergência e condutividade elétrica. Utilizou-se o delineamento inteiramente casualizado com quatro repetições. Verificou-se que com o desenvolvimento das sementes de grão-de-bico as camadas mais internas do tegumento sofrem colapso. O acúmulo de amido e proteína já está em andamento nas sementes de vagens verdes. A pectina se destaca dentre os compostos constituintes de parede celular dos esclereídes do tegumento. Em geral, sementes obtidas de vagens com coloração externa amarela, amarelo-dourado e marrom apresentam maior germinação e vigor.

ABSTRACT The maturation stage of seeds affects their physiological quality soon after harvest. The aim of this study was to evaluate the anatomical, histochemical, and physiological changes in chickpea ‘BRS Aleppo’ seeds obtained from pods in different maturity stages. Pods were collected in five maturity stages: green, yellow-green, yellow, golden-yellow, and brown. For anatomical and histochemical characterization, sections were stained with toluidine blue, Lugol’s solution, Xylidine-Ponceau (XP), and ruthenium red. For evaluation of physiological changes, seeds were dried to 12% (wet basis) water content. The following tests were performed: seed water content, germination, percentage and speed of seedling emergence, and electrical conductivity. A completely randomized experimental design was used, with four replications. As the chickpea seeds develop, the innermost layers of the seed coat collapse. Accumulation of starch and protein were already observed in the seeds of green pods and pectin was prominent compound of the seed coat sclerids. In general, chickpea seeds from yellow, golden-yellow and brown pods have greater germination and vigor.

Abstract Coffee tree is a shrub with dimorphic branches. The orthotropic stem grows vertically with two near-horizontal plagiotropic branches, per node, in opposite phyllotaxy. The consecutive nodes of the orthotropic stem are organized in parastichies. We report here mutant plants of Coffea arabica with triple plagiotropic branch, resulted from the whorled phyllotaxy of the orthotropic stem. In mutant plants three plagiotropic branches in the same node are separated by angles of approximately 120o, while in normal plants two plagiotropic branches in the same node are separated by angles of approximately 180o. In mutant plants the angles of the parastichies increase approximately 50o clockwise between consecutive nodes, while in normal plants the angles increase approximately 87o. The plant architecture is changed. The triple plagiotropic branch is a putative mutant with potential to be explored in coffee breeding programs. The hypotheses for the origin of the mutation and the research perspectives are discussed.

RESUMO. Objetivou-se acompanhar as alterações estruturais, a deposição de reservas e determinar a composição química de sementes de pimenta malagueta e biquinho durante a sua ontogênese. Frutos foram coletados aos 25, 40, 55, 70, 85 e 100 dias após a antese (DAA). Após a coleta, as sementes foram extraídas e fixadas em FAA 50 e, armazenadas em álcool 70%. Posteriormente, foram incluídas em Historesina Metacrilato e seccionadas em micrótomo. Os cortes foram submetidos à coloração com Azul de Toluidina, para análise anatômica e a análise histoquímica realizada com XylidinePonceau, Periodic acid Schiff (PAS) e Lugol. Para reação com Floroglucina Ácida e Sudam III, foram realizados cortes em criomicrótomo. Verificou-se que houve lignificação progressiva das células do tegumento. As proteínas e os lipídeos constituem os principais compostos de reserva das sementes de pimenta malagueta e biquinho, estocados no embrião e endosperma. O amido constitui uma fonte transitória de reserva para o desenvolvimento do embrião. As reservas lipídicas são observadas nas células do embrião e do endosperma dos 25 aos 100 DAA. Aos 100 DAA, as sementes de pimenta malagueta e biquinho apresentam concentração de proteínas de 0,33 e 0,62 g g-1 M.S. e lipídeos de 0,30 e 0,25 g g-1 M.S. respectivamente.

ABSTRACT. This study aimed to evaluate the structural changes and reserve deposition of malagueta and biquinho pepper seeds and to determine their chemical composition during ontogeny. The fruits were collected 25, 40, 55, 70, 85, and 100 days after anthesis (DAA). After collection, the seeds were extracted and fixed in FAA 50 and then stored in 70% ethanol. Subsequently, the seeds were embedded in methacrylate (Historesin) and sectioned with a microtome. The sections were stained with Toluidine blue O for anatomical analysis and Xylidine Ponceau, Periodic acid Schiff (PAS) and Lugol’s iodine solution for histochemical analysis. Sections were made using a cryomicrotome for acid phloroglucinol staining and Sudan III tests. Progressive lignification of the seed coat cells was observed. Proteins and lipids were the main reserve compounds of malagueta and biquinho pepper seeds stored in the embryo and endosperm. Starch served as a transient reserve during embryo development. The lipid reserves were observed in embryo and endosperm cells from 25 until 100 DAA. At 100 DAA, the protein contents of the malagueta and biquinho pepper seeds were 0.33 and 0.62 g g-1 DM and the lipid contents were 0.30 and 0.25 g g-1 DM, respectively.

RESUMO A colheita das sementes de cenoura no momento adequado tem reflexos diretos sobre a sua qualidade fisiológica. O objetivo do trabalho foi avaliar as alterações fisiológicas, anatômicas e histoquímicas em sementes de cenoura colhidas em diferentes estádios de desenvolvimento e estabelecer a época mais adequada para a colheita. Foram colhidas umbelas secundárias aos 14, 21, 28, 35, 42, 49, 56 e 63 dias após antese (DAA). Para a caracterização anatômica e histoquímica os cortes foram corados com Azul de toluidina, Xylidine Ponceau, Lugol, Sudan black B e submetidos à luz polarizada. As sementes foram submetidas aos seguintes testes: grau de umidade, matéria seca, germinação, primeira contagem, porcentagem e índice de velocidade de emergência de plântulas. Sementes de cenoura ‘Brasília’, aos 14 DAA, encontram-se em divisão e expansão celular e apesar da reduzida matéria seca, lipídios foram identificados no endosperma. Aos 21 DAA, além de lipídios, proteínas e amido foram identificados. A maturidade fisiológica das sementes ocorreu aos 35 DAA, com o endosperma ocupando praticamente todo volume das sementes, o embrião ocupando uma pequena região cilíndrica e o tegumento apresentando uma única camada de células. Nesta fase, as sementes apresentaram 56% de grau de umidade e a coloração do pericarpo era verde-amarelo. A máxima germinação e vigor das sementes ocorreu aos 30 DAA, um pouco antes da maturidade fisiológica (35 DAA). Portanto, a época ideal para a colheita das sementes de cenoura ‘Brasília’ é a partir de 30 DAA, quando as sementes apresentam máxima qualidade fisiológica.

ABSTRACT The adequate time for carrot seed harvest influences its physiological quality. The objective of this study was to evaluate physiological, anatomical and histochemical changes in carrot seeds harvested at different stages of development and to establish the most appropriate harvest time. Secondary umbels were harvested at 14, 21, 28, 35, 42, 49, 56 and 63 days after anthesis (DAA). For seed anatomical and histochemical characterization, sections were stained with Toluidine blue stain, Xylidine Ponceau, Lugol’s iodine, Sudan Black B and submitted to polarized light. Seed moisture content, seed dry matter, germination, first count, emergence percentage and emergence speed index of seedlings were evaluated. Cultivar Brasília carrot seeds at 14 DAA are in cell division and expansion. In addition, as lipids were identified in the endosperm, despite the seed low dry matter. At 21 DAA, reserve substances such as protein and starch were also identified. Along the seed development process, deposition of lignin occurs in the endocarp cells, and this collapsed lignified layer represents the resistance layer of the seeds. Physiological maturity, represented by the maximum dry matter accumulation, occurs at 35 DAA, with the endosperm occupying almost all volume of seeds, the embryo occupying a small cylindrical region and the integument showing a single layer of cells. At this time, the seeds presented 56% moisture content and the color of the pericarp is green-yellow. Maximum seed germination and vigor occurred at 30 DAA, just before physiological maturity was reached (35 DAA). Thus, the ideal time to harvest the seeds of cultivar Brasília is from 30 DAA, where the seeds have maximum physiological quality.

Pfaffia glomerata é uma espécie nativa da América do Sul e de ocorrência natural em alguns Estados do Brasil. Porém, as populações naturais de fáfia têm sido ameaçadas em decorrência do intenso extrativismo, em virtude de suas propriedades terapêuticas de interesse. No presente estudo, objetivou-se estimar a diversidade genética de quatro populações naturais oriundas da bacia do Rio Paraná. Os indivíduos foram multiplicados in vitro e caracterizados de acordo com o padrão eletroforético de marcadores RAPD, utilizando-se 268 marcas polimórficas obtidas a partir de 67 primers. As estimativas de distância genética foram obtidas pelo complemento aritmético do coeficiente de Nei e Li, e os genótipos agrupados de acordo com o método UPGMA. Três populações situadas próximas às margens do rio Paraná e na ilha do Mineiro apresentaram baixos índices de diversidade entre elas, e estas possuem o mesmo fluxo de dispersão dos propágulos. A população situada nas proximidades da margem do rio Ivaí (afluente do rio Paraná) apresentou maiores valores de diversidade dentro da população e entre as populações, indicando que sua preservação é prioritária e a origem da variabilidade pode estar relacionada ao fluxo de dispersão de propágulos.

Pfaffia glomerata is a native species from South America, occurring naturally in some states of Brazil. The ever growing interest by the species, mainly due to its important therapeutic properties, has threatened the natural populations, as exploitation has occurred in a rather predatory way. The present study aimed to compare the genetic diversity of four natural populations originated from of the area of the Paraná River basin (Paraná and Mato Grosso States). The individuals were propagated in vitro and characterized by means of RAPD markers. A total of 267 polymorphic marks were obtained from 67 primers. The genetic distance estimates were obtained based on the complement arithmetic of Nei and Li's similarity coefficient, and the genotypes were grouped according to the UPGMA method. Three populations from the margin of the Paraná River and at Mineiro Island presented low diversity levels among them, though possessing the same propagule dispersal flow. The population located in the proximities of the margin of the Ivaí river (tributary of the river Paraná) presented greater diversity values within and among the populations, suggesting that its preservation should be a priority and that the origin of the genetic variability may be related to the dispersion flow of the vegetative propagules.

Doenças causadas por bactérias constituem um novo desafio à cultura do Eucalyptus spp., podendo, inclusive, limitar o uso de clones suscetíveis. O presente trabalho objetivou avaliar a eficiência de antibióticos e rizobactérias na inibição do crescimento "in vitro" de isolados de bactérias fitopatogênicas ao Eucalyptus spp. na fase de viveiro e de campo. O antibiótico sulfato de amicacina e a rizobactéria S1 (Bacillus subtillis) destacaram-se quanto à inibição do crescimento do isolado fitopatogênico IP1-05 (Pseudomonas chichorii), enquanto a cefoxitina causou maior inibição dos isolados BSV16 e RVV11 (Rhizobium sp.). Os antibióticos de uso comercial na área agronômica, Mycoshield (oxitetraciclina) e Agrimicina (estreptomicina e tetraciclina) foram pouco efetivos. Este trabalho proporciona embasamento a alternativas para controle biológico de doenças bacterianas em mudas de Eucalyptus spp. na fase de viveiro.

Diseases caused by bacteria represent a new challenge for Eucalyptus spp. and may also limit the use of susceptible clones. Our study aimed at an evaluation of the efficiency of antibiotics and rhizobacteria in inhibiting "in vitro" growth of phytopathogenic bacteria isolates in Eucalyptus spp. during the nursery stage and in the field. The antibiotic amicacine sulfate and rhizobacterium S1 (Bacillus subtilis) stood out inhibiting the growth of the phytopathogenic isolate IP1-05 (Pseudomonas chichorii), whereas cefoxitin caused a greater inhibition of the isolates BSV16 and RVV11 (Rhizobium sp.). The commercial antibiotics for agricultural use Mycoshield (oxitetracycline) and Agrimycin (estreptomycin and tetracycline) were little effective. This study offers a base for alternatives of biological control of bacterial diseases in Eucalyptus spp. nursery seedlings.

Fases meióticas e estádios de micrósporos de pimentão (Capsicum annuum L. cv. Azeth) foram determinados e associados com características morfológicas adotadas para a seleção de botões florais a serem utilizados na indução de androgênese. Plantas foram mantidas em casa-de-vegetação para coleta dos botões florais, que foram separados em seis classes de acordo com a relação de tamanho entre cálice e corola e presença de pigmentos nas anteras. As anteras foram fixadas em metanol: ácido acético na proporção de 3:1 e armazenadas a -20º C. Preparações citogenéticas desse material foram montadas pela técnica de dissociação e secagem ao ar e coradas com solução de Giemsa. As observações dos botões foram realizadas sob lupa e as preparações citogenéticas em microscópio ótico. Imagens dos botões florais, das anteras e das fases meióticas foram digitalizadas em computador para documentação. Variações de fases meióticas dentro de cada classe de botão floral foram observadas. Embora o critério de presença de antocianina na extremidade das anteras tenha sido aplicado para outras variedades, o mesmo não se mostrou adequado para a determinação do estádio de micrósporo neste estudo. As fases meióticas foram citogeneticamente identificadas; contudo, não foi possível estabelecer sua associação com as classes dos botões florais. Entretanto, botões com o tamanho de cálice coincidindo com o da corola apresentaram maior número de micrósporos em estádio adequado para a cultura de anteras.

In the present study, morphological characters adopted for floral bud selection used for androgenesis induction were associated with pepper (Capsicum annuum L. cv. Azeth) meiotic phases and microspore stages. Floral buds were harvested from greenhouse-grown plants and separated into six classes according to size relationships between calyx and corolla, and anthocyanin pigmentation in anthers. After sorting by size, buds were fixed using a methanol: acetic acid (3:1) solution at -20ºC. Cytogenetic preparations were mounted using an adaptation of an air-drying technique and staining through a phosphate buffer Giemsa solution. Bud observations were accomplished under a stereo-microscope and the cytogenetic preparations in an optic microscope. Recordings of floral buds and meiotic phases were performed with an image digitizing computer system. Variations on the meiotic phases were observed within each class. Although the approach based on anthocyanin pigmentation on anthers has been applied to another pepper varieties, it was not a reliable trait for determination of the microspore stage. Meiotic phases were citogeneticaly identified, although bud stage could not be associated with it. On the other hand, buds having the same calyx and corolla sizes presented a larger number of microspores in a suitable stage for anther culture.