ABSTRACT

No abstract

Seed germination and seedling morphology of Smilax polyantha (Smilacaceae). Biota Neotrop. 11(2): http:// www.biotaneotropica.org.br/v11n2/en/abstract?article+bn00411022011 Abstract: Brazilians have been using the underground organs of Smilax species in alternative medicine since the 19 th century because of their anti-rheumatic qualities. However, even nowadays, these species are explored only by extractivism. Studies on seed germination and development of these organs could be useful to preserve these plants. After germination, seedling development of Smilax polyantha was analyzed to understand underground stem formation. Furthermore, to analyze the ontogenesis of the underground system, seedlings aged from one to twelve months were sectioned. One of the most striking features of this species is the presence of two stem branching systems. The plumule gives rise to the first stem branching system with negative geotropism. Its first underground axillary bud sprouted into the other caulinar axis with positive geotropism. The horizontal growth and the subsequent thickening of this underground organ depended on the development of axillary buds from basal nodes of the previous branches. The cotyledonary bud did not play a role in the underground formation, as previously described in the literature for this genus, but the buds of the basal cataphylls built the second stem branching system. In this study we discuss the terminology and suggest calling this second stem branching system a rhizophore. Keywords: anatomy, development, greenbrier, rhizome, rhizophores. MARTINS, A.R., PÜTZ, N., NOVEMBRE, A.D.L.C., PIEDADE, S.M.S. & APPEZZATO-DA-GLÓRIA, B. Germinação e morfologia de plântulas de Smilax polyantha (Smilacaceae). Biota Neotrop. 11(2): http://www. biotaneotropica.org.br/v11n2/pt/abstract?article+bn00411022011Resumo: As espécies de Smilax L. são utilizadas na medicina popular brasileira desde o século 19 devido às propriedades anti-reumáticas atribuídas aos órgãos subterrâneos de todas as espécies. No entanto, ainda hoje, essas espécies são exploradas apenas por extrativismo. Estudos sobre a germinação e o desenvolvimento dos órgãos subterrâneos podem ser úteis para preservar essas plantas. Após a germinação, o desenvolvimento de plântulas de Smilax polyantha foi analisado para compreender a formação do sistema subterrâneo. Para a análise da ontogênese do sistema subterrâneo foram seccionadas plantas em diferentes estágios de desenvolvimento entre um e doze meses. Uma das características mais marcantes desta espécie é a presença de dois sistemas de ramificação caulinar. A plúmula dá origem ao primeiro sistema caulinar de ramificações com geotropismo negativo. As gemas axilares subterrâneas desse primeiro eixo caulinar originam o segundo eixo caulinar com geotropismo positivo. O crescimento horizontal e o espessamento do órgão subterrâneo dependem do desenvolvimento de gemas axilares de nós basais dos ramos anteriores. A gema cotiledonar não participa da formação do caule subterrâneo, como descrito anteriormente na ...

With the aim of studying the organogenesis in vitro in Passiflora edulis Sims f. flavicarpa Deg., the passionfruit, leaf-derived explants were cultured on media containing NAA or BAP and incubated either in continuous darkness or in light. The histological events leading to de novo organ formation were evaluated. Darkness induces rhizogenesis in the presence of NAA, whereas direct shoot regeneration is stimulated by light and BAP. This latter condition is recommended for passionfruit micropropagation as several adventitious shoot buds were formed from meristemoids of parenchymal origin.

-(Phenolic compound production during ectomycorrhizal infection of Eucalyptus urophylla roots by two isolates of Pisolithus tinctorius in vitro). Physiological and structural diversity of ectomycorrhizal fungi can lead to differences in their behaviour during root infection and colonization. In incompatible interactions, the plant reacts against infection with structural and biochemical defenses, including production of antifungal compounds like phenolics. This study investigated the initial stages of ectomycorrhizal infection in interactions between P. tinctorius and E. urophylla to determine the plant reaction. E. urophylla seedlings were inoculated with a compatible (1604) or an incompatible (185) isolate of P. tinctorius. Extration of phenolic compounds was carried out at 0, 12, 24, 72, 96 and 120 hours after inoculation. At the same time, root samples were collected, processed and embedded in glycol methacrylate resin. Sections were studied under ligth microscopy. Ectomycorrhiza was formed on eucalyptus roots by 96 hours after inoculation with isolate 185 and by 24 hours in plants inoculated with isolate 1604. Structural reactions were not observed by light microscopy. On the other hand, a higher concentration of phenolic compounds in roots inoculated with the isolate 185 was observed 96 hours after inoculation. Although only plants inoculated with isolate 185 showed significant differences in phenolic concentration at the various infection stages, phenol accumulation could not be associated with delay in infection. RESUMO -(Produção de compostos fenólicos durante a infecção ectomicorrízica por dois isolados de Pisolithus tinctorius em Eucalyptus urophylla in vitro). Devido à grande variedade fisiológica e morfológica entre os fungos ectomicorrízicos, é possível observar variações no seu comportamento durante o estabelecimento da simbiose. Este trabalho teve como objetivos caracterizar as etapas da infecção micorrízica por dois isolados de P. tinctorius em E. urophylla, além de verificar a ocorrência de defesas estruturais e bioquímicas na planta. Plântulas de E. urophylla foram inoculadas com os isolados de P. tinctorius obtidos de eucalipto (1604) ou de Pinus (185). Após 0, 12, 24, 72, 96 e 120 horas da inoculação com cada um dos isolados, foi efetuada a dosagem de compostos fenólicos no tecido radicular. Nestes mesmos períodos foram feitos cortes anatômicos das raízes para verificar o desenvolvimento da infecção. Os cortes histológicos não evidenciaram reações estruturais de defesa das plantas nestes períodos testados. No entanto, foi observada colonização mais rápida pelo isolado 1604, o qual iniciou a adesão à raiz 24 horas após a inoculação. O isolado 185 só foi observado na raiz após 96 horas. A dosagem de compostos fenólicos mostrou variação significativa durante a infecção pelo isolado 185 e maior concentração nas raízes inoculadas com este isolado após 96 horas da inoculação. Porém, este acúmulo não impediu a continuidade de seu desenvolvimento na raiz. Neste trabalho não foi observada re...

This study aimed to study the effect of astringency reduction using ethanol and application of 1-MCP in ‘Giombo’ persimmons, storage in cold chamber at 5ºC and to assess its physiological and structural alterations. After the deastringency treatment using ethanol, and the application of 1-methylcyclopropene (1-MCP), the fruits were stored at 5ºC and 90% RH during 60 days and shelf life (SL) for 5 days at 22ºC. The dosage of 1.70 ml/kg-1 ethanol during 12 hours was efficient for the astringency removal in ‘Giombo’ persimmons. However, deastringency using ethanol reduces pulp firmness and 1-MCP preserves this characteristic both in detannized fruits and in controls. The increase of soluble pectins and solubilization did not foster the polymerization of the soluble tannins both in control and detannized fruits. ‘Giombo’ persimmons displayed a severe firmness reduction, increase of soluble pectins, and degradation of the parenchyma cells, gelling of the pulp, increase of the production of ethanol and acetaldehyde after 60 days of storing + 5 days SL, inclusively in control fruits, and those treated with 1-MCP. These results suggest, cultivar ‘Giombo’ is susceptible to damages at 5ºC and that further studies are required using different temperatures to improve the storage.

Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30ºC and 20-30ºC) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30ºC in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovateelliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics. Rev. Biol. Trop. 60 (1): 495-504. Epub 2012 March 01.

No abstract