Rescue and vegetative propagation of Eremanthus erythropappus (DC. ) Ma ish in natural stand / Resgate e propagação vegetativa de Eremanthus erythropappus (DC. ) MacLeish em povoamentos naturais

Abstract The native stands of 'candeia' (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This study's objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of 'candeia' in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of 'candeia', with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

Resumo Os povoamentos nativos de candeia (Eremanthus erythropappus) vêm sendo explorados por planos de manejo devido ao potencial econômico do óleo essencial. O resgate de árvores adultas, bem como a aplicação de técnicas silviculturais que favoreçam o restabelecimento do povoamento podem contribuir para a conservação genética dessa espécie. O objetivo desse trabalho foi avaliar a eficiência de técnicas de propagação para o resgate de 26 matrizes de candeia em um povoamento natural manejado e discutir sobre a rizogênese. Em agosto de 2017, as árvores foram induzidas à rebrota por meio da decepa, seguida da exposição e escarificação das raízes. A emissão brotações e morfologia foram avaliadas de acordo com a origem (toco ou raiz). Após esse período, 19 matrizes tiveram as brotações recolhidas para o preparo de estacas apicais, que foram tratadas com ácido indolbutírico (AIB). A sobrevivência das estacas na saída da casa de vegetação (SCV), o enraizamento na saída da casa de sombra (SCS), a morfologia e a anatomia da raiz foram avaliados. Aos 189 dias, a escarificação das raízes resultou em 76,92% de emissão de brotos. O percentual de matrizes brotadas, número de brotos por matriz, comprimento, diâmetro e relação comprimento/diâmetro dos brotos aumentaram ao longo do período avaliado. Somente 12,2% das estacas sobreviveram na SCV e 7,9% enraizaram na SCS. A estaquia resultou na formação de um minijardim clonal de candeia com sete das dezenove matrizes submetidas à propagação. As análises anatômicas mostraram a diferenciação das células na região do parênquima floemático e a presença de cristais de inulina nas paredes dos elementos de vaso do xilema secundário. A indução de brotos radiculares pode ser usada como prática silvicultural visando o restabelecimento de fragmentos nativos manejados.

Vegetative rescue potential of Brazil nut through epicormic shoots on detached branches

Obtaining juvenile material may favor the clonal propagation of Brazil nut, Bertholletia excelsa. We aimed to assess the emission of epicormic shoots on detached branches of Brazil nut trees as a function of the mother tree and branch diameter, in order to provide juvenile material for use in clonal multiplication. The experimental design was completely randomized in a 6 (mother trees) x 3 (stem diameter: < 20 20-40 and 40-80 mm) factorial design, with four replicates. Every five days the number of shoots emitted was counted and the sprouting speed index and average sprouting time were calculated. The number of epicormic shoots and the sprouting speed index were dependent on the interaction between mother tree and branch diameter. Branches with larger diameter (20-40 and 40-80 mm) showed higher potential for obtaining propagules for use in Brazil nut clonal multiplication (cutting, grafting and in vitro cultivation). (AU)

Genomic Insights into the Rice Blast Fungus through Estimation of Gene Emergence Time in Phylogenetic Context

The rice blast fungus, Magnaporthe oryzae, is an important pathogen of rice plants. It is well known that genes encoded in the genome have different evolutionary histories that are related to their functions. Phylostratigraphy is a method that correlates the evolutionary origin of genes with evolutionary transitions. Here we applied phylostratigraphy to partition total gene content of M. oryzae into distinct classes (phylostrata), which we designated PS1 to PS7, based on estimation of their emergence time. Genes in individual phylostrata did not show significant biases in their global distribution among seven chromosomes, but at the local level, clustering of genes belonging to the same phylostratum was observed. Our phylostrata-wide analysis of genes revealed that genes in the same phylostratum tend to be similar in many physical and functional characteristics such as gene length and structure, GC contents, codon adaptation index, and level of transcription, which correlates with biological functions in evolutionary context. We also found that a significant proportion of genes in the genome are orphans, for which no orthologs can be detected in the database. Among them, we narrowed down to seven orphan genes having transcriptional and translational evidences, and showed that one of them is implicated in asexual reproduction and virulence, suggesting ongoing evolution in this fungus through lineage-specific genes. Our results provide genomic basis for linking functions of pathogenicity factors and gene emergence time.

Vegetative propagation of Plukenetia polyadenia by cuttings: effects of leaf area and indole-3-butyric acid concentration / Propagação vegetativa de Plukenetia polyadenia por estacas: efeitos de área foliar e concentração de ácido indol-3-butírico

Abstract The seeds of Plukenetia polyadenia have high levels of unsaturated fatty acids and are used as medicine and food for native people in the Peruvian and Brazilian Amazon. The objective of this study was to develop a method for vegetative propagation of Plukenetia polyadenia by rooting of cuttings. The experiment was laid out in a randomized complete block design with 12 treatments and 3 replications of 8 cuttings, in a 3 × 4 factorial arrangement. The factors were: 3 levels of leaf area (25, 50 and 75%) and 3 indole-3-butyric acid - IBA concentrations (9.84, 19.68 and 29.52mM) and a control without IBA. Data were submitted to analysis of variance and means were compared by Tukey test at 5% probability. Our results show that the use of cuttings with 50% of leaf area and treatment with 29.52mM of IBA induced high percentages of rooting (93%) and the best root formation. Vegetative propagation of Plukenetia polyadenia by cuttings will be used as a tool to conserve and propagate germplasm in breeding programs.

Resumo As sementes de Plukenetia polyadenia têm altos níveis de ácidos graxos insaturados e são utilizadas como medicamentos e alimentos para as pessoas nativas da Amazônia Peruana e Brasileira. O objetivo do trabalho foi desenvolver um método de propagação vegetativa de Plukenetia polyadenia por meio do enraizamento de estacas em câmeras de sub-irrigação. Foi utilizado um delineamento de blocos ao acaso com 12 tratamentos e 3 repetições de 8 estacas, e esquema fatorial 3 × 4. Os fatores foram: 3 níveis de área foliar (25, 50 e 75%) e 3 doses de ácido indol-3-butírico - AIB (9,84; 19,68 e 29,52mM) e um controle sem AIB. Os dados foram submetidos à análise de variância e as médias foram comparadas pelo teste de Tukey a 5% de probabilidade. A maior taxa de enraizamento de estacas (93%) foi obtida com 29,52mM de AIB como indutor hormonal e estacas com área foliar de 50%. A propagação vegetativa de Plukenetia polyadenia por estacas será usada como ferramenta para conservar e propagar germoplasma em programas de melhoramento.

Tipos de estacas e substratos na propagação vegetativa da menta (Mentha arvensis L. ) / Types of cuttings and substrates in the vegetative propagation of mint (Mentha arvensis L. )

O trabalho teve como objetivo avaliar a propagação vegetativa da menta utilizando diferentes tipos de estacas e substratos. O experimento foi conduzido no Horto de Plantas Medicinais da Unimontes, campus Janaúba - MG. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 2 x 4 (dois tipos de estacas e quatro diferentes substratos) com quatro repetições, sendo cada parcela representada por seis estacas. Foram analisadas as variáveis comprimento de parte aérea e de raízes, massa seca de parte aérea e de raízes e número total de brotações formadas por planta. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Scott-Knott a 5% de probabilidade. A interação entre os fatores estacas e substratos não foi significativa para as variáveis estudadas, passando-se a estudar o efeito isolado de cada fator. A propagação de Mentha arvensis L. pode ser realizada tanto por estacas apicais como medianas, utilizando o substrato solo + areia + esterco bovino (2:1:1) para a produção de mudas de qualidade.

The purpose of the study was to evaluate the vegetative propagation using different types of mint cuttings and substrates. The experiment was conducted in the Garden of Medicinal Plants of Unimontes, in Janaúba - MG. The experimental design was completely randomized (CRD) in 2 x 4 factorial schemes (two types of poles and four different substrates) with four replications and each plot was represented by six cuttings. The variables analyzed were the length of the shoots and roots, the dry matter of the shoots and roots and the total number of shoots per plant. The data were subject to ANOVA and the means were compared by Scott-Knott's test at 5% of probability. The interaction among stem cuttings and substrates was not significant for the variables studied, thus, the isolated effect of each factor was studied. The propagation of Mentha arvensis L. can be performed either by apical cuttings as medians, using the substrate soil + sand + manure bovine (2:1:1) for the production of quality seedlings.

Tipos de estacas e diferentes substratos na propagação vegetativa da erva cidreira (quimiotipos I, II e III) / Types of cuttings and different substrates in the vegetative propagation of the Lippia alba (chemotypes I, II and III)

A erva-cidreira [Lippia alba (Mill.) N. E. Brown] é comumente utilizada no Brasil como planta medicinal por suas propriedades analgésica, antiespasmódica, calmante e sedativa. O objetivo do trabalho foi avaliar o efeito do tipo de estaca e de diferentes substratos sobre a propagação vegetativa da erva-cidreira quimiotipos I, II e III. O material botânico utilizado foi estacas de erva-cidreira quimiotipos I, II, e III, com aproximadamente 12 cm de comprimento. No primeiro experimento, foram utilizadas estacas (apicais e basais) dos três quimiotipos, em um esquema fatorial 2 x 3. No segundo experimento, as estacas dos três quimiotipos foram propagadas em três substratos: substrato comercial + esterco bovino curtido (na proporção de 1:1); substrato comercial + palha de arroz carbonizada (na proporção de 1:1); e substrato comercial, em um esquema fatorial de 3 x 3 com 4 repetições, onde se determinou a massa fresca e seca da raiz, caule e folhas. Estacas apicais e basais podem ser utilizadas na propagação vegetativa da erva-cidreira quimiotipos I, II e III. As misturas substrato comercial + palha de arroz carbonizada e substrato comercial + esterco bovino curtido são recomendadas para a propagação vegetativa da erva-cidreira quimiotipos I, II e III.

The Lippia alba is commonly used in Brazil as a medicinal plant for its analgesic properties, antispasmodic, calming and sedative. The objective of this study was to evaluate the effect of cutting type and different substrates on the propagation of the Lippia alba chemotypes I, II and III. The botanical material used was stakes Lippia alba chemotypes I, II and III, with approximately 12 cm in length. In the first experiment, we used cuttings (apical and basal) of the three chemotypes in a 2 x 3 factorial arrangement. In the second experiment, cuttings of three chemotypes were propagated in three substrates: commercial substrate + cattle manure (1:1), commercial substrate + carbonized rice hulls (1:1) and commercial substrate, in a factorial 3 x 3 with 4 replicates, was determined fresh and dry weight of root, stem and leaves. Apical and basal cuttings can be used in the propagation of the Lippia alba chemotypes I, II and III. The commercial substrate mixtures + carbonized rice hulls and commercial substrate + cattle manure are recommended for the propagation of lemongrass chemotypes I, II and III.

Regulation of eurotium repens reproduction and secondary metabolite production

Eurotium repens [Anamorph Aspergillus repens] was isolated 1 from spoiled fruit. It reproduced sexually at different sucrose concentrations up to 50% [w/v]; water activity, 0.79. It reproduced asexually at high sucrose concentration 60% [w/v] water activity, 0.75. The concentrations of all detected amino acids were higher in the teleomorph than the anamorph except that of glycine, while alpha aminoadipic acid and alanine were detected in teleomorph only. The extracellular secondary metabolites produced by the teleomorph and anamorph stages were variable and different except epoxysuccinic acid and 2-pyruvylamino benzamide which were produced by the two stages. Glycine, arginine and calcium chloride unlike glutamic acid, aspartic acid and alanine, plays an important role in the induction of teleomorph stage formation at high sucrose concentration 60% [w/v]

Propagação de sapotizeiro (Manilkara zapota L. ) por estaquia / Propagation of sapoti tree (Manilkara zapota L. ) for cutting

Dois acessos de sapotizeiro, planta nativa do sul do México e da América Central, pertencentes à Coleção de Frutíferas Nativas e Exóticas da UNESP/FCAV, Campus de Jaboticabal, foram estudados quanto à propagação por estaquia. O primeiro ensaio consistiu de imersão rápida da base de estacas semi-herbáceas enfolhadas dos acessos selecionados FCAV-III e FCAV-VII em solução hidroalcoólica (50%) de ácido indolbutírico (AIB) nas concentrações 0, 1.000, 3.000, 5.000 e 7.000 mgL-1 e o preparo de estacas com e sem lavagem do látex exsudado, em recipiente contendo água pura por período de 14 horas. Esse ensaio foi conduzido em esquema fatorial 5 x 2 x 2 (doses de AIB x acessos x preparo das estacas). O segundo ensaio constou da imersão das estacas herbáceas enfolhadas do acesso FCAV-III nas doses de AIB acima mencionadas. Ambos os ensaios foram distribuídos no delineamento foi inteiramente casualizado com quatro repetições e 10 estacas cada. Todas as estacas foram coletadas na primavera e preparadas com cerca de 12 cm de comprimento, plantadas em vermiculita de textura média e conduzidas em condições de câmara de nebulização por aspersão intermitente sob telado com 50 % de luminosidade. Os dois acessos testados não enraizaram e os tratamentos utilizados não foram capazes de induzir apreciável emissão de raízes.

Two sapoti tree accesses (Manilkara zapota), native plants of south of Mexico and of América Central, belonging to the Collection of Fruitful Native and Exotic of UNESP/FCAV, Jaboticabal Campus, was studied with relationship to the cutting propagation. The first test consisted of fast immersion of cutting base semi-herbaceous foliage of selected accesses FCAV-III and FCAV-VII. The ttreatments were alcoholic solution (50%) of indolbutíric acid (IBA) in concentrations of 0, 1,000, 3,000, 5,000 and 7,000 mgL-1. and the cuttings preparing with and without latex exudate washing for a period of 14 hours in recipient with pure water. This trial was set in 5 x 2 x 2 factorial scheme (IBA concentrations x accesses x cutting preparation) The second test consisted the herbaceous foliage immersion of FCAV-III access in IBA concentrations above. Both experiments were distributed in randomized design with four replications and 10 cuttings each. All cuttings were collected in spring and prepared with about 12 cm of length, planted in medium texture vermiculite and carried under conditions intermittent mist spray flashing in chamber with 50% light. The two accesses tested not rooted and treatments were not able to induce the roots emission

Associação de isolados de Trichoderma spp. e ácido indol-3-butírico (AIB) na promoção de enraizamento de estacas e crescimento de maracujazeiro / Association of isolates of Trichoderma spp. And indole-3-butyric acid (IBA) in promoting root and growth of passion

Este trabalho teve como objetivo estudar o efeito de isolados de Trichoderma no enraizamento e no desenvolvimento de estacas de caule de Passiflora edulis Sins f. flavicarpa Deg. juntamente com o ácido indol-3-butírico (AIB). Os experimentos foram realizados em casa-de-vegetação, adotando-se o delineamento experimental em blocos casualizados, em esquema fatorial (6x2), com cinco tratamentos: (isolados de Trichoderma) com e sem aplicação do AIB e quatro repetições. A parcela experimental constituiu-se de um vaso com quatro plantas. A análise dos dados obtidos revelou diferença significativa entre os tratamentos quanto à massa de matéria seca e fresca das plantas de maracujazeiro. Os cinco isolados de Trichoderma apresentaram efeito positivo no incremento de matéria seca e fresca. Houve interação significativa entre os fatores com e sem hormônio. Não foi detectado efeito significativo do uso de Trichoderma, quanto ao enraizamento de estacas. No entanto, os isolados proporcionaram resultados positivos no incremento de matéria fresca e seca nas estacas de maracujazeiro.

This work aimed to study the effect of isolates of Trichoderma on rooting and development of cuttings of Passiflora edulis Sins f. flavicarpa Deg. together with indol butyric-3- acid (IBA). The experiments were performed under greenhouse conditions, adopting the experimental design of randomized blocks in factorial scheme (6x2) and using the following treatments: five isolates of Trichoderma, with and without application of the hormone IBA, with four replications. The experimental plot consisted of a pot with four plants. The analysis of data revealed significant differences among treatments for dry matter weight of Passiflora plant. The five isolates of Trichoderma showed positive effect on increasing both dry and fresh weight. There was an Significant interaction between factors with and without hormone. No significant effect of Trichoderma was found. However, the isolates showed positive effects on fresh and dry mass of Passiflora cuttings

Induction of somatic embryogenesis as an example of stress-related plant reactions / Inducción de embriogénesis somática como un ejemplo de las reacciones de la planta en relación al estres

In this review, we address the role of stress as one of the principal causes for a cell or tissue to change its pre-existing somatic program, reprogramming itself to express the embryogenic pathway. The focus of this paper is the effect of different stress conditions on the induction phase of plant somatic embryogenesis, as well as the development of embryogenic competence as a result of the applied stresses. We also present a variety of data that link plant somatic embryogenesis, DNA methylation and oxidative stress response.

Produção de mudas de Aloysia gratissima (Gillies & Hook. ) Tronc. por meio da propagação sexuada e assexuada / Aloysia gratissima (Gillies & Hook. ) Tronc. seedling production through sexual and asexual propagation

A alfazema-do-Brasil é planta de importância medicinal, como produtora de terpenos. A principal descrição etnofarmaco-botânica aponta como sendo eficaz para infecções brônquicas, pulmonares e da bexiga. O objetivo do trabalho foi estudar a propagação de A. gratissima visando a obtenção de mudas. Na propagação sexuada estudou-se a influência da temperatura na presença e ausência de luz e três épocas de coleta das sementes (março, junho e setembro). Na propagação via semente foram testados três diferentes substratos (areia, palha de arroz carbonizada, Plantmax®). Na propagação vegetativa foram testados dois tipos de estacas (herbáceas e semi-lenhosas) e de dois substratos (areia e Plantmax®). Os resultados indicaram que na propagação sexuada, a germinação das sementes foi maior nas temperaturas constantes de 20 e 25°C, e a melhor época de coleta de sementes foi em março. O substrato comercial mostrou-se superior para o crescimento das plântulas, atingindo 93,25 por cento de emergência das sementes e 100 por cento de sobrevivência. Para a propagação assexuada, as estacas herbáceas em substrato comercial e areia apresentaram 96 e 95 por cento de enraizamento, respectivamente.

Brazilian-lavender is a medicinally important plant since it produces terpenes. As regards ethnopharmacology, it is mainly efficient against bronchial, lung and bladder infections. The aim of this work was to study Aloysia gratissima propagation for seedling production. In sexual propagation, temperature influence in the presence and absence of light and three seed harvesting times (March, June, and September) were studied. Three different substrates (sand, carbonized rice husk, Plantmax®) were also evaluated for seed germination. In vegetative propagation, two cutting types (herbaceous and semihardwood) and two substrates (sand, Plantmax®) were tested. Seed germination was higher under constant temperatures of 20 and 25ºC, and March was the best seed harvest time for sexual propagation. The commercial substrate was the best for seedling growth, peaking 93.25 percent seedling emergency and 100 percent survival. For asexual propagation, herbaceous cuttings in the commercial substrate and sand presented 96 percent and 95 percent rooting, respectively.

Human Cloning based on the Shi'ite's view

Religious positions on human cloning are pluralistic in modes of argument and conclusions. Some religious thinkers argue that cloning a human is immoral and propose a ban on human cloning. Some other religious thinkers contend that human cloning could be morally justified under some circumstances. The Roman Catholic Church expressed a vigorous opposition to the procedure, and a Vatican editorial denounced the research as [intrinsically perverse] Catholic moral theologians invoked norms of individuality, dignity, and wholeness in condemning this research while many Conservative Protestant scholars held that this research contravened basic notions of personhood such as freedom, the sanctity of life, and the image of God, and some other Protestant scholars noted its potential medical benefits and advocated careful regulation rather than prohibition. Some Jewish and some Islamic thinkers [Shi'ite] encourage continuing laboratory research on the possibility of cloning human beings only in pursuit of a worthy objective. The Islamic scholars emphasize that every scientific discovery is ultimately a revelation of the divinely ordained creation. In this research cloning scientific bases and Shi'ite authorities beliefs [as a major religious group who agree with human cloning] will be discussed

Transcription of meiotic-like-pathway genes in Giardia intestinalis

The reproductive mechanism of Giardia intestinalis, considered one of the earliest divergent eukaryotes, has not been fully defined yet. Some evidence supports the hypothesis that Giardia is an exclusively asexual organism with a clonal population structure. However, the high genetic variability, the variation in ploidy during its life cycle, the low heterozygosity and the existence of genes involved in the meiotic-like recombination pathway in the parasite's genome cast doubt on exclusively asexual nature of Giardia. In this work, semiquantitative RT-PCR analysis was used to assess the transcription pattern of three meiosis-like-specific genes involved in homologues recombination: dmc1, hop1 and spo11. The mRNAs were amplified during the parasite's differentiation processes, encystation and excystation, and expression was found at each stage of its life cycle. A semiquantitative assessment also suggests that expression of some of the genes is regulated during encystation process.

Wild Manihot species: botanical aspects, geographic distribution and economic value

A total of 98 Manihot species have been recognized in the genus. All of them are native to the tropics of the New World, particularly Brazil and Mexico. The cultigen, Manihot esculenta Crantz (cassava), grows throughout the lowland tropics. Wild species vary in growth habit from acaulescent or short shrubs to tree-like. Because of their adaptations to different conditions, they are gene reservoirs for tackling many abiotic and biotic stresses such as improving root quality and resistance to diseases. They have been used successfully by the first author for improving protein content, seed-fertility, apomixis, resistance to mealy bug, and tolerance to drought. A table of the most important species from an economic viewpoint is presented.

Descrição histológica da via genital masculina e hermafrodita de escargots das espécies Achatina fulica E Achatina monochromatica / Histology description of the male and hermafrodite genital vias of the escargots Achatina fulica AND Achatina monochromatica

O objetivo deste trabalho foi descrever a histologia da via genital masculina e hermafrodita dos escargots das espécies Achatina fulica e Achatina monochromatica. Foram usados 10 exemplares adultos de cada espécie para análise histológica. Após o processo seletivo, pesagem e tomada das medidas da concha, os espécimes foram sacrificados por congelamento em freezer, a -2ºC por aproximadamente 10min. Para a exposição dos órgãos reprodutores foi efetuada uma incisão longitudinal iniciada na extremidade cranial e, acompanhando a torção do corpo, até a extremidade caudal. Cada animal foi dissecado, sobre uma placa de Petri, sob imersão em formol a 10% para melhor preservação dos tecidos. Foram coletados fragmentos representativos de cada segmento do sistema reprodutor e observou-se que a estrutura histológica dos mesmos não apresentou diferenças notórias, com exceção do ovotestis do Achatina fulica, no qual se constatou um número maior de células pigmentadas no epitélio germinativo do que, nesse mesmo epitélio, no Achatina monochromatica.

The aim of this work was to make histological description of the male and hermaphrodite genital system of escargots of the species Achatina fulica and Achatina monochromatica. Ten adult copies of each species were used for such analysis. After a selective process, weighting and measuring the shell, the specimens were sacrificed by freezing in freezer to -2ºC for approximately 10min. Reproductive organs were exposed by longitudinal incision made in the cranial extremity and by accompanying the sprain of the body, until the tail extremity. Each animal was dissected over a Petri plate, under immersion in 10% phormol for better preservation of the tissues. Representative fragments of each segment of the reproductive system were collected and it was observed that their histological structure did not present evident differences, except for the Achatina fulica ovotestis in which a larger number of pigmented cells was observed in the germinative epithelium than in the same epithelium in the Achatina monochromatica.

Morphology and cultural behavior of Botryococcus protuberans with notes on the genus.

The green alga Botryococcus protuberans was isolated from its natural environment and its morphology under different cultural conditions was examined. The alga was characterized by a high starch content and reddish oil drops as the assimilatory products. Photosynthetic pigments, Chl a, Chl b, carotenoids and xanthophylls are present. Modification of environmental conditions in modified Chu-10 medium resulted in optimum growth of the alga. Fatty acid composition revealed palmitic acid being the major component, while lauric acid, myristic acid and stearic acid were found in less quantity.

Efectos de la temperatura sobre el crecimiento individual y formación de zooides en Stylaria lacustris (Linnaeus, 1767) (Oligochaeta, Naididae) / Temperature effects on individual growth and zooids formation in Stylaria lacustris (Linnaeus, 1767) (Oligochaeta, Naididae)

Los cultivos realizados con S. lacustris demostraron que la temperatura juega un papel de importancia en la tasa de la reproducción, en cuanto al número de zooides producido por individuo así como también al tamaño alcanzado por los mismos. Por otro lado, regularía la tasa de crecimiento y la reproducción sexual, dando lugar a la madurez de los individuos cuando aumenta la temperatura. El tiempo de vida promedio de los individuos inmaduros se estimó en 15 días, siendo este valor independiente de la temperatura utilizada en los cultivos. Los individuos maduros vivieron en promedio 37 días. La supervivencia en S. lacustris fue decreciendo gradualmente, según una curva de tipo lll. La expectativa de vida presentó su pico a la edad de 16 días y se mantuvo aproximadamente constante hasta una edad de 28 días a partir de la cual fue decreciendo en forma persistente hasta la última edad alcanzada. Se estimó el crecimiento individual, según la ecuación de von Bertalanffy, para los organismos mantenidos a 23 ± 2 ºC y a 14 ± 1 ºC. En aquellos individuos cultivados a mayor temperatura se registró una mayor talla, aunque su tasa de crecimiento fue menor que la de los individuos mantenidos a 14 ºC.

The experiments carried out with S. lacustris showed that the temperature plays a role of importance in the rate of asexual reproduction, as for the number of zooids produced by individual, as well as to the size reached by them. On the other hand, it would regulate the rate of growth and the sexual reproduction, giving place to the maturity of the individuals when temperature increases. The life time of the immature individuals was estimated in 15 days, being this independent of the temperature used in the cultures. The mature individuals lived on the average 37 days. The survival in S. lacustris was falling gradually, following a curve of type lll. Life expectancy presented its major value at the age of 16 days and stayed approximately constant up to an age of 28 days, after then falled persistently until the last reached age. The individual growth according to von Bertalanffy equation, was estimated for the organisms maintained at 23 ± 2 ºC and at 14 ± 1 ºC. Those individuals cultivated at higher temperature attained a bigger size, although their rate of growth was smaller than those maintained at 14 ºC.

Asexual Recombination in a uvsH Mutant of Aspergillus nidulans

Mutations in the gene uvsH of Aspergillus nidulans result in increased spontaneous chromosome instability and increased intragenic and intergenic mitotic recombination in homozygous diploids. The aim of the present work was to obtain a uvs mutant of A. nidulans and to use it for the isolation of asexual recombinants (parameiotic segregants). The mutant uvsH, named B511, showed normal frequency of meiotic recombination in sexual crosses and high frequency of parameiotic segregants in the parasexual crossings with master strains (B511//A757 and B511//A288). Asexual haploid recombinants (parameiotic segregants), diploid and aneuploid segregants were recovered directly from the uvs//uvs+ heterokaryons (B511//A757 and B511// A288). Parameiotic segregants originated through mitotic crossing-over and independent assortment of chromosomes.

Study on the asexual sporulation of Aspergillus niger under blue light induction and analysis of its subtractive library / 生物工程学报

The effect of blue light (BL) on the morphological development of Aspergillus niger was studied by the scanning electron microscopy (SEM) observation. Comparing with the darkness, BL was able to stimulate development of sporangiophore and conidiosphore, promote grownth of mycelium. Suppression subtractive hybridization (SSH) was conducted with tester cDNA which was from 39 to approximately 40h-old mycelium cultured under darkness and driver cDNA which was from mycelium illuminated for 3 to approximately 4h under BL after dark growth. Some cDNA bands were obtained by suppression PCR (polymerase chain reaction) with the subtractive cDNA. Positive bacterial clones were randomly picked and identified by colony PCR method. Through sequence alignments from GenBank, most of differential cDNA fragments were highly identical with some redox enzymes existing in mitochondria, and the quantitative measurement of these differential mRNA by real time RT-PCR indicated that relative expression of the identified gene fragments under BL induction was higher than that under darkness. Furthermore, the result suggested that some respiratory chain redox enzymes of mitochondria were involved in the photoresponse and consequently influence the metabolism. Among differential cDNA fragments two unkown sequences were found and their complete gene and gene function remained to be investigated.