Floristic composition and structure of two seasonal Deciduous Forest Patches in Alto-Uruguai, SC

Em dois fragmentos florestais da Floresta Estacional Decidual (FED) do Alto-Uruguai, SC, foram aplicados os m\ue9todos de parcelas (MP) e de pontos-quadrantes (MQ) visando a comparar os m\ue9todos amostrais e caracterizar a riqueza flor\uedstica e composi\ue7\ue3o estrutural. Foram inventariadas 91 esp\ue9cies, sendo que 52 foram encontradas no sub-bosque (sem valor madeireiro), com destaque para Sorocea bonplandii , Gymnanthes concolor e Trichilia claussenii . As outras 39 esp\ue9cies emergentes no dossel florestal s\ue3o de uso madeireiro, sendo as mais abundantes Apuleia leiocarpa , Nectandra megapotamica , Cabralea canjerana e Holocalyx balansae . As esp\ue9cies de maior densidade e \ue1rea basal foram praticamente as mesmas em ambos os fragmentos florestais, independente do m\ue9todo usado. O MP detectou uma maior diversidade de esp\ue9cies e uma maior densidade de plantas por \ue1rea comparativamente ao MQ, embora ambos os m\ue9todos detectassem esp\ue9cies diferentes. Todavia, o uso simult\ue2neo dos dois m\ue9todos possibilitou em uma maior cobertura da diversidade de esp\ue9cies nas duas \ue1reas, com redu\ue7\ue3o no tempo para o invent\ue1rio. Em ambos os m\ue9todos, detectaram-se erros amostrais acima do esperado e quanto menores os valores do erro amostral, maior foi a similaridade dos resultados das avalia\ue7\uf5es entre os m\ue9todos. Paradoxalmente a riqueza de esp\ue9cies presentes na FED contrasta com o pequeno n\ufamero de fragmentos que restaram neste ecossistema. Importante ressaltar que esses fragmentos s\ue3o as \ufaltimas fontes de sementes para a recoloniza\ue7\ue3o de \ue1reas abandonadas ou degradadas, como tamb\ue9m para conserva\ue7\ue3o e uso em programas de melhoramento gen\ue9tico de ess\ueancias florestais nativas e banco de sementes in situ.In two forest remnants located in Seasonal Deciduous Atlantic Forest of Alto-Uruguai region of Southern Brazil, the plots (MP) and point-centered-quarter (MQ) methods were used aiming to characterize the floristic richness and structural composition. 91 species were identified, 52 of them were classified as understory species (without timber value), being the most abundant Sorocea bonplandii , Gymnanthes concolor and Trichilia claussenii species. The others were classified as timber species, being the most abundant Apuleia leiocarpa , Nectandra megapotamica , Cabralea canjerana and Holocalyx balansae . The species of higher density and basal area were practically the same in both forest patches, independently from the inventory method used. The MP detected a higher number of species diversity as well as the higher value for plant density by area, comparatively to MQ, although both methods detected different species. The simultaneous use of MQ and MP resulted in a higher coverage of species diversity in both areas, with a reduction in time to perform the inventory. In both methods, sampling error above of the expected value was detected, but the smaller these values, the greater the similarity among the results provided by both methods. Unfortunately, the species richness occurring in the FED contrasts with the small number of remaining patches in this ecosystem. It is important to highlight that these patches are the last repositories for seed to be used in colonizing degraded areas as well as for conservation, improvement and in situ seed bank program with native plant species

Estrutura e composição florística de dois fragmentos da Floresta Estacional Decidual do Alto-Uruguai, SC.

Andiroba is one of the Amazon species with great potential of exploration for timber and non-timberforest products (NFTPs). This work was carried out with the objective of studying the population structure,spatial distribution and seed yield in a native forest of andiroba in the south of Roraima state. A permanentsample plot of 300 x 300 m (9 ha) was installed and all the trees with DBH equal or superior to 10 cm wereidentified, mapped and measured. In each tree, the light climate, crown form and lianas load were appraised.To identify the spatial distribution, the medium variance/average rate and the Morisita’s Index were used.The seed yield data were obtained by the seed weighing, being 145 trees monitored during 2006. Thepopulation presented a diametric distribution of the j inverted type, and a seed yield of 65,4 kg.ha-1 withaverage of 8,3 kg.tree-1 was observed. DBH ≥ 30 cm was considered as borderline for commercial seed yield,allowing stratifying the population in juveniles (DBH ≤ 30 cm) and adults (DBH > 30 cm). The spatialdistribution analysis showed that adult individuals presented random distribution and the juveniles tendencyof grouping.Em dois fragmentos florestais da Floresta Estacional Decidual (FED) do Alto-Uruguai, SC, foram aplicados os métodos de parcelas (MP) e de pontos-quadrantes (MQ) visando a comparar os métodos amostrais e caracterizar a riqueza florística e composição estrutural. Foram inventariadas 91 espécies, sendo que 52 foram encontradas no sub-bosque (sem valor madeireiro), com destaque para Sorocea bonplandii, Gymnanthes concolor e Trichilia claussenii. As outras 39 espécies emergentes no dossel florestal são de uso madeireiro, sendo as mais abundantes Apuleia leiocarpa, Nectandra megapotamica, Cabralea canjerana e Holocalyx balansae. As espécies de maior densidade e área basal foram praticamente as mesmas em ambos os fragmentos florestais, independente do método usado. O MP detectou uma maior diversidade de espécies e uma maior densidade de plantas por área comparativamente ao MQ, embora ambos os métodos detectassem espécies diferentes. Todavia, o uso simultâneo dos dois métodos possibilitou em uma maior cobertura da diversidade de espécies nas duas áreas, com redução no tempo para o inventário. Em ambos os métodos, detectaram-se erros amostrais acima do esperado e quanto menores os valores do erro amostral, maior foi a similaridade dos resultados das avaliações entre os métodos. Paradoxalmente a riqueza de espécies presentes na FED contrasta com o pequeno número de fragmentos que restaram neste ecossistema. Importante ressaltar que esses fragmentos são as últimas fontes de sementes para a recolonização de áreas abandonadas ou degradadas, como também para conservação e uso em programas de melhoramento genético de essências florestais nativas e banco de sementes in situ

Análise genética do caráter período de espigamento em trigo

The inheritance of heading time, in the field, was studied in crosses involving four Brazilian wheats (Triticum aestivum L.) (IAS 55, Nobre, B 20 and PF 70553) and two alien wheats (Yugoslávia 715/70 and NS 1406). The parents, their F1 and F2 cross generations, and the two first backcrosses (BC1F1 and BC2F1) were investigated to obtain a better understanding of how heading time is inherited and to assess the possibility of changing this trait through selection. Gene action appeared to be additive and of dominance. Evidence for epistasis, as an important contributor to heading time, was lacking. A minimum of three genetic factors of blocks of genes appear to control head time. While long cycle wheats carry recessive alleles at all three loci, the short cycles are governed by one two dominant genes. Heritability for heading time was estimated to be high, indicating that considerable progress could be made in shifting mean heading time by selecting and recombining early-heading F2 plants.A herança do período de espigamento a campo, foi estudada nos cruzamentos envolvendo quatro trigos (Triticum aestivum L.) brasileiros (IAS 55, Nobre, B 20 e PF 70553) e dois estrangeiros (Yugoslávia 715/70 e NS 1406). As gerações parentais F1, F2 e os dois primeiros retrocruzamentos (RC1F1 e RC2F1) foram analisados para melhor entender como a data de floração é herdada e a possibilidade de modificar a manifestação deste caráter através de seleção. A ação génica parece ser aditiva e de dominância. Evidências de epistasia contribuindo para o caráter não foi detectada. Um mínimo de três fatores genéticos, ou blocos de genes, parece controlar o período de espigamento. Enquanto o trigo de ciclo longo carrega alelos recessivos em todos os três locos, os de ciclo curto são governados por um ou dois genes dominantes. A herdabilidade estimada para espigamento é alta, indicando que considerável progresso pode ser feito através da seleção e recombinações de plantas F2

Mecanismos de indução à reprodução sexual em trigo

The paper presents the response to vernalization requirement of 98 varieties and lines of common wheat from Tenth and Eleventh International Winter Wheat Perforrnance Nursery (IWWPN) during grown season of 1979 and 1980. Sexual reproduction can be greatly accelerated in winter wheats by first subjecting the slightly applied seeds to alcohol, HgCl2, water and low temperatures (near freezing) in the dank for 20 days before sowing. When so treated, winter wheats sown in the field at higher growing temperatures in long day will behave as spring wheats.Este trabalho apresenta a resposta à vernalização requerida em 98 variedades e linhagens de trigo panificável proveniente da 10.a e 11.a International Winter Wheat Performance Nursey (IWWPN) durante a estação fria de 1979 e 1980. A reprodução sexual pode ser altamente acelerada em trigos de inverno com a aplicação de álcool, HgCl2 , água e baixa temperatura (perto do ponto de congelamento) em condições úmidas por 20 dias antes da semeadura. Quando tratados e semeados em áreas com altas temperaturas e dias longos, os trigos de inverno reagem como trigo de primavera

The interplay between hormone signaling and defense gene expression in grapevine genotypes carrying genetic resistance against Plasmopara viticola

The present study aimed to investigate plant defense related pathways during Plasmopara viticola infection in Vitis vinifera varieties. Plant material consisted of 'Chardonnay' (no Rpv), 'Regent' (Rpv3-1), 'Bronner' (Rpv3-3+Rpv10), 'Calardis Blanc' (Rpv3-1+Rpv3-2), and the breeding selection GF15 (Rpv1+Rpv3-1). Gene expression analysis was carried out for the varieties 'Regent', GF15, 'Bronner', and 'Chardonnay'. Hormonal quantification was performed for jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), indole-3-acetic acid (IAA), and trans-zeatin-ribose (tZR). The samples were collected from plants cultivated in vitro inoculated with Plasmopara viticola sporangia, and collected at 0, 1-, 3-, 5-, and 7-days post inoculation (DPI) for gene expression; and 0, 3, 5, and 7 DPI for hormonal quantification. The results showed an interaction between genotype and time post inoculation in gene expression and hormonal pathways linked with pathogen recognition. Both jasmonate and salicylic acids were involved in the resistance response. The role of stilbenes acting against the pathogen at different times was also confirmed. Changes in the expression of genes linked to cell defense were observed in all evaluated genotypes; however, genotypes with R-loci responded more quickly than the variety without R-loci, activating mechanisms of cell death, resulting in symptoms of hypersensitivity

Potencial genético da aveia, como produtora de grãos no sul do Brasil

Yield and other agronomic traits were studied in six experiments with oats (Avena sativa L.) established in the Southern Brazil, during the years 1982 to 1984. The grain yield and hectoliter wight in different genotypes showed high progress; however, plant stature and heading time did not change in the last three years. The results suggest that plant breeding programmes should release new genotypes to increase stability and yield potential. O rendimento de grãos e outros caracteres de importância agronômica foram estudados em seis experimentos de aveia estabelecidos na região sul do Brasil, entre os anos de 1982 a 1984. O rendimento de grãos e o peso do hectolitro nos diferentes genótipos demonstraram um alto progresso; entretanto, a estatura e o ciclo de desenvolvimento de planta não apresentaram alterações nos últimos três anos. Os resultados sugerem que os programas de melhoramento devem continuar criando e testando novos genótipos anualmente, com o objetivo de incrementar a estabilidade e o potencial de rendimento de grãos.

Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses

The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species