Seed dispersal, population structure and the mating system of plant species can have great consequences on the genetic structure of populations. Vriesea gigantea is a bromeliad from southeastern Brazil which is self-compatible and pollinator dependent for fruit set. Its populations are fertile in terms of the production of flowers, pollen, fruits and seeds. To assess the importance of seed supply for gene flow, colonization and distribution of adult individuals, the seed dispersal and population structure of V. gigantea were studied. Seeds are dispersed over short distances; most seeds land close to the mother plant. This pattern coincides with the reported aggregate distribution of bromeliad seedlings. Population structure results showed high seedling recruitment, because 51.3% developed into adults, although few juveniles reached this stage. This result is different from that for other bromeliad species from different habitat conditions. Seed dispersal and population structural patterns are consistent with previous molecular studies, revealing that V. gigantea populations are genetically structured, with low gene flow and a moderate outcrossing rate. Barbará T, Martinelli G, Palma-SilvaC, Fay MF, Mayo S, Lexer C. 2009. Genetic relationships and variation in reproductive strategies in four closely related bromeliads adapted to neotropical 'inselbergs': Alcantarea glaziouana, A. regina, A. geniculata and A. imperialis (Bromeliaceae). Annals of Botany 103: 65-77. Bennett BC. 1986. Patchiness, diversity, and abundance relationships of vascular epiphytes. Selbyana 9: 70-75. Bennett BC. 1991. Comparative biology of Neotropical epiphytic and saxicolous Tillandsia species: population structure. Journal of Tropical Biology 7: 361-371. Benzing DH. 1978. Germination and early establishment of Tillandsia circinnata Schlecht. (Bromeliaceae) on some of its hosts and other supports in southern Florida. Selbyana 2: 95-106. Benzing DH. 1981. Bark surfaces origin and maintenance of diversity among angiosperm epiphytes: a hypothesis. Selbyana 5: 248-255. Benzing DH. 1990. Vascular epiphytes: general biology and related biota. Cambridge: Cambridge University Press. Benzing DH. 2000. Bromeliaceae: profile of an adaptive radiation. Cambridge: Cambridge University Press.Bittencourt JVM, Sebbenn AM. 2007. Patterns of pollen and seed dispersal in a small, fragmented population of the wind-pollinated tree Araucaria angustifolia in southern Brazil. Heredity 99: 580-591. Borges LA, Sobrinho MS, Lopes AV. 2009. Phenology, pollination, and breeding system of the threatened tree Caesalpinia echinata Lam. (Fabaceae), and a review of studies on the reproductive biology in the genus. Flora 204: 111-130. Brown AHD. 1990. Genetic characterisation of plant mating system. In: Brown AHD, Clegg MT, Kahler AL, Weir BS, eds. Plant population genetics, breeding and genetic resources. Sunderland, MA: Sinauer Associates, 145-162. Bullock JM, Clarke RT. 2000. Long distance seed dispersal by wind: measuring and modeling the tail of the curve. Oecologia 124:...

Inbreeding depression is a reduction of fitness in the progeny of closely related individuals and its effects are assigned to selfing or biparental inbreeding. Vriesea gigantea is a self‐compatible bromeliad species distributed in the Brazilian Atlantic rainforest and habitat destruction and fragmentation and collection have decreased the natural populations. We aim to describe the occurrence of inbreeding depression (δ) in three natural populations of V. gigantea and to correlate this phenomenon with previous studies of fertility, genetic diversity, population genetic structure, gene flow, mating system and seed dispersal in this species. Fifty‐four adult plants were sampled and 108 flowers were used for pollination treatments (selfing, outcrossing and control). For adult plants, we analysed plant and inflorescence height, flower numbers and seed set. In the progenies, evaluated parameters included seed germination and seedling survival rate. The results indicated low to moderate levels of inbreeding depression in V. gigantea (δ = 0.02 to 0.39), in agreement with molecular data from a previous study. Vriesea gigantea populations tolerate some degree of inbreeding, which is consistent with previous results on fertility, mating system, genetic diversity and gene flow. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 312–319.

No abstract

The bacterial strains SEMIA 587 and 5019 (Bradyrhizobium elkanii), 5079 (Bradyrhizobium japonicum), and 5080 (Bradyrhizobium diazoefficiens) are recommended for soybean inoculants in Brazil. In several countries, the current regulations are insufficient to induce companies for improving the quality of their products, leading to low performance and subsequent abandonment of inoculant use. From 2010 to 2014, 1086 samples coming mainly from Argentina and the southern region of Brazil were analyzed for viable cells counting, strains identification, and purity analysis according to the SDA/MAPA no. 30/ 2010 Normative Instruction. Most products were imported and formulated in liquid carriers with 5.0 × 10 9 colony-forming units (CFU)/mL. The strains most frequently used were SEMIA 5079/5080. Only 2.21% of samples had contaminants. The guaranteed concentration of viable cells in inoculants mostly ranged from 4.1 × 10 9 to 5.0 × 10 9 CFU/mL or CFU/g. The most frequently found concentration was above 1.1 × 10 10 CFU/mL or CFU/g, which was higher than the product guarantee. The inoculants used for soybean crop in Brazil have excellent quality, leading the country to the leadership in taking advantage of the biological nitrogen fixation benefits for a productive and sustainable agriculture.

No abstract

No abstract

No abstract

O cornichão é uma leguminosa forrageira perene hiberno-primaveril de grande importância para o Rio Grande do Sul, destacando-se pela capacidade de se manter em solos relativamente ácidos e pouco férteis. Com este trabalho, objetivou-se a seleção de rizóbios para cornichão tolerantes à acidez e ao Al tóxico e eficientes na fixação biológica de N em solos de baixa fertilidade. Foram avaliados 52 isolados de rizóbios de Lotus spp. obtidos de solos de cinco localidades do Rio Grande do Sul. Os rizóbios foram avaliados quanto à diversidade genética, à tolerância a pH 4,2 e ao Al tóxico. Entre os rizóbios tolerantes a fatores de acidez, sete foram avaliados quanto à eficiência simbiótica com plantas, em casa de vegetação, em vasos com solo não estéril. Observou-se alta diversidade genética entre os rizóbios estudados, dos quais 16 foram tolerantes a pH 4,2 e a 50 µM de Al em meio de cultura, produzindo populações da ordem de 10(7) até 10(8) UFC mL-1. Os sete rizóbios testados em casa de vegetação superaram as estirpes atualmente recomendadas para a produção de inoculantes, o que demonstra a existência, em solos do Rio Grande do Sul, de rizóbios tolerantes à acidez do solo e eficientes como fixadores de N em plantas de cornichão.