RESUMO Os recursos hídricos urbanos são de grande importância para a manutenção do ecossistema, e sua qualidade precisa ser avaliada para identificar possíveis fontes de contaminação. O presente trabalho teve como objetivo utilizar o teste de Allium cepa L. e análise físico-química na avaliação da qualidade da água do Arroio Matadouro, Ijuí, Rio Grande do Sul. As coletas foram realizadas em quatro locais do arroio urbano e as amostras usadas para análises físico-químicas e teste de Allium cepa. Avaliaram-se os seguintes parâmetros: demanda bioquímica de oxigênio, demanda química de oxigênio, fósforo total, nitrogênio amoniacal, sólidos suspensos e surfactantes, índice de estado trófico, índice mitótico e aberrações cromossômicas. Com relação às análises físico-químicas, o ponto 2 foi o que apresentou mais alterações, enquanto no ponto 1 (nascente) os indicadores demonstraram melhor qualidade da água. O índice de estado trófico apresentou valor médio de 59,17, classificando o arroio em grau eutrófico. A análise do índice mitótico mostrou que todos os pontos tiveram estimulação da proliferação celular. As aberrações cromossômicas foram verificadas em todas as amostras, porém mais elevadas no ponto 4. O teste Allium cepa demonstrou possível potencial citotóxico e genotóxico e, associado aos parâmetros físico-químicos, revelou ser boa ferramenta de avaliação da qualidade da água. Este estudo mostrou que o arroio urbano está impactado pelas ações do entorno, principalmente aquelas relacionadas aos poluentes de origem doméstica.

ABSTRACT Urban water resources are of great importance for the maintenance of the ecosystem and their quality needs to be evaluated to identify possible sources of contamination. The present study aimed to use the Allium cepa L. test and physical-chemical analysis to assess the water quality of stream Matadouro, Ijuí, Rio Grande do Sul. The collections were carried out in four places of the urban stream and the samples used for physical-chemical analysis and Allium cepa test. The following parameters were evaluated: biochemical oxygen demand, chemical oxygen demand, total phosphorus, ammoniacal nitrogen, suspended solids and surfactants, trophic state index, mitotic index, and chromosomal aberrations. With regard to physical-chemical analysis, point 2 had the most changes, while point 1 (spring), the indicators showed better water quality. The trophic state index presented an average value of 59.17, classifying the stream in eutrophic degree. The mitotic index analysis showed that all points had stimulation of cell proliferation. Chromosomal aberrations were verified in all samples, however, higher in point 4. The Allium cepa test showed possible cytotoxic and genotoxic potential and, associated with the physical-chemical parameters, proved to be a good tool for assessing water quality. This study indicated that the urban stream is impacted by the surrounding actions, especially those related to domestic pollutants.

HIGHLIGHTS Low genetic similarity in Paspalum notatum accessions. High genetic distance among diploid accessions. The accessions have good potential to breeding program.

Abstract Paspalum notatum is a polymorphic species with two accepted varieties, according to the ploidy level. The ploidy level is closely related to the reproductive mode of this species. Usually, diploid cytotypes have sexual reproduction, and tetraploid cytotypes have an apomictic reproduction. Apomixis limits genetic recombination, hindering the development of new cultivars. The identification of sexual plants represents many possibilities in breeding programs. This study aimed to analyze the chromosome number in P. notatum accessions under agronomic evaluation. Ploidy level was determined in 25 accessions. Two ploidy levels were detected, resulting in 21 tetraploid and four diploid accessions. The four diploid accessions originate from Argentina and Uruguay, in a region close to the origin of Pensacola, which is a diploid sexual cultivar of P. notatum. These new diploid accessions may be useful in the development of breeding programs of Paspalum species.

Abstract Evolutionary analyses have been widely used for evaluation of genetic diversity of natural populations and correlate these data to the fitness of the species, especially in the case of threatened species. Calydorea crocoides occurs in a restricted area at altitudes from 800 to 1500 m in southern Brazil and is considered endangered. A study assessing genetic diversity, cytogenetic features and ecological niche was performed aiming to characterize C. crocoides by multidisciplinary approaches. Molecular data highlighted that most of the total variation (76%; p < 0.001) was found within populations and the parameters of genetic diversity were high at the species level (PPB = 98.97%; I = 0.4319; h = 0.2821). Gene flow (Nm) was estimated in 0.97 individuals per generation. Cytogenetically, C. crocoides presents a bimodal karyotype and low asymmetry. DAPI banding pattern was uniform, but the CMA-signal evidenced a pericentric inversion in the population ESC688. The species presents high pollen viability and two different morphologies of pollen grains. Our data showed high levels of polymorphism maintained in this species that could ensure conservationist practices in which the main goal is to preserve the evolutionary potential of the species through the maintenance of genetic diversity.

ABSTRACT The objective of this study was to assess the genetic diversity among accessions of Paspalum notatum based on morphological marker traits and identify those morphological traits that contribute most to the variability among accessions. Fifty-three accessions were evaluated for the following traits: length, width, color, and pubescence of sheath; length, width, insertion angle, color of midrib, and pubescence of leaves; number, length, and angle of racemes; length of flowering stems; and plant growth habit (erect or prostrate). Multivariate analysis of the quantitative morphological data based on the Mahalanobis distance and UPGMA method grouped the accessions into 19 heterogeneous clusters. The relative contribution of each trait to cluster formation was obtained using the Singh method. Qualitative morphological traits were used to construct a dendrogram based on Jaccard's similarity, generating 13 clusters. Based on the morphological traits investigated, there is high genetic variation among accessions of P. notatum, demonstrating that these accessions have a good potential for a breeding program. Length of racemes, width of sheath, length of flowering stems, and length of leaves were found to contribute most to the variability among accessions. A number of traits contributed to a lesser degree. The set of characters used are representative of the vast phenotypic plasticity observed in P. notatum, a diversity which is likely to be related to the species apomictic form of reproduction and the origin of the accessions.

Plants of the family Iridaceae are well represented in the grassland vegetation of southern Brazil, occurring in the Pampa and Atlantic Forest biomes. Nevertheless, little is known about the taxonomy and evolution of Iridaceae species in southern Brazil. The main goal of this review is to compile published information about South American Iridaceae, and to discuss the evolution and genetic diversity of the family presenting our own research data in the light of the published literature. The main focus is on the genera Calydorea, Cypella, Herbertia, and Sisyrinchium. Aspects of reproductive system and of pollinator attraction are also discussed.

A espécie medicinal Solidago micrglossa DC., a qual é nativa da América do Sul, é usada como infusão (chá) para desordens estomacais na medicina popular. O objetivo desse estudo foi avaliar o potencial efeito citotóxico dessas infusões no ciclo celular de Allium cepa. Folhas in natura de três populações dessa espécie foram utilizadas no preparo das infusões em duas concentrações: 1,75 mg/mL e 14 mg/mL. Células de raízes de cebola (Allium cepa) foram usadas como sistema teste nos ensaios in vivo. As lâminas foram feitas através da técnica de esmagamento. As células foram analisadas em todos os ciclos celulares de A. cepa, totalizando 6000 células para cada grupo de bulbos. O índice mitótico (IM) foi calculado e a análise estatística foi realizada através do teste Qui-quadrado (χ2 = 0,05). Os resultados mostraram que as infusões de S. microglossa na maior concentração (14 mg/mL) causou uma redução no IM comparado com os controles nas populações estudadas. Nas concentrações comumente usadas pelas pessoas houve um aumento significativo do IM em relação ao controle nas populações 1 e 3 e foi reduzido na população 2. Em conclusão, infusões de S. microglossa apresentam efeito antiproliferativo na maior concentração testada.

The medicinal specie Solidago microglossa DC., which is native from South America, is used as infusion (tea) for stomach disorders in popular medicine. This study aimed to evaluate the potential cytotoxic effect of these infusions on the cell cycle of Allium cepa. In natura leaves of three populations of this species were used in preparing infusions at two concentrations: 1.75 mg/mL and 14 mg/mL. Onion (Allium cepa) root-tip cells were used as test system in in vivo assays. Slides were done through smashing technique. Cells were analyzed in all cell cycles of A. cepa, totalizing 6000 cells for each group of bulbs. The mitotic index (MI) was calculated, and the statistical analysis was carried out through the Chi-square test (χ2 = 0.05). The results show that the infusions of S. microglossa at a highest concentration (14 mg/mL) caused a significant reduction in the MI compared with control in the studied populations. In concentrations commonly used by people there was a significant increase of MI in relation to controlled populations 1 and 3 and a decrease in population 2. In conclusion, infusions of S. microglossa presented antiproliferative effect at a highest concentration.

Achyrocline satureioides (marcela) é utilizada na medicina popular brasileira, na forma de chá, como tratamento de patologias digestivas e inflamatórias. O efeito anti-proliferativo de infusões de marcela sobre o ciclo celular da cebola foi avaliado, utilizando-se inflorescências de marcela recém coletadas (2005) e após armazenamento por 30 meses (2003). Preparou-se as infusões em duas concentrações: 5,0 mg/mL (concentração usual como chá) e 20 mg/mL. Utilizaram-se 3 grupos de 6 bulbos de cebola para cada população de marcela. Retirou-se um grupo de bulbos controle de cada população. Todos os bulbos enraizados em água destilada foram transferidos para os extratos de marcela e permaneceram por 24 horas, (os bulbos controle permaneceram em água). As radículas foram coletadas, fixadas em etanol-ácido acético (3:1) por 24 h e estocadas em álcool 70%. Foram analisadas 6000 células por grupo de bulbos, e os índices mitóticos calculados submetidos a análise estatística pelo teste chi2 a 5%. Conclui-se que as infusões de marcela possuem ação antiproliferativa sobre o ciclo celular da cebola e que essa ação inibitória da divisão celular aumenta conforme aumento da concentração, bem como após o armazenamento.

Achyrocline saturoides (marcela) is used in Brazilian folk medicine as a tea in the treatment of digestive and inflammatory diseases. The anti-proliferative effect of infusions of marcela on onion cell cycle was evaluated by using the inflorescences of recently collected marcela and after the storage for 30 months. Marcela inflorescences were collected for the infusion preparations in 2003 and in 2005 (used still fresh). We prepared the infusions at two concentrations 5.0 mg/mL (concentration used as tea) and 20 mg/mL. We used two groups of six onion bulbs for each population of marcela, and one group of bulbs of each population was withdrawn as a control group. All bulbs rooted in distilled water and after they were transferred to the extracts of marcela and they were kept there for 24 hours (control bulbs remained under water). The root tips were collected, after fixed in ethanol acetic acid (3:1) for 24 hours and, stored under alcohol 70%. A total of 6000 cells per group of bulbs was analyzed, and the mitotic indexes were calculated and undergone to statistical analysis by using chi2 at 5%. The conclusions were that the infusions of marcela have anti-proliferative action on the cell cycle of onion and that this inhibitory action on the cell division increases according to the increase of the infusion concentration, after storage as well.