Polyploidy in Paullinia (Paullinieae, Sapindaceae) and its Systematic Implications

Chromosome counts from 23 populations of 16 species of Paullinia (Paullinieae, Sapindaceae) from South America are given. These include first counts for ten species in six of the thirteen sections of this genus. Counts of 2n 5 24 for P. cristata, P. revoluta, P. thalictrifolia, P. trigonia, P. uloptera, P. rhomboidea; 2n5 48 for P. seminuda and P. sp.; and two cytotypes of 2n 5 48 and 2n 5 96 for P. carpopoda and P. rubiginosa; and ca. 2n 5 216 for P. cupana var. sorbilis. The chromosome number 2n524 appears to be conserved for this genus, however, in this contribution polyploid series are cited for the first time for some native species. These results were interpreted in a phylogenetic context.Fil: Urdampilleta, Juan Domingo. Universidade Estadual de Campinas; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Forni Martins, Eliana R.. Universidade Estadual de Campinas; BrasilFil: Ferrucci, Maria Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Solanaceae

First molecular cytogenetic studies in C. parvifolium Sendtn.Fil: Cruz, María Victoria Romero da. Universidade Estadual Do Campinas. Instituto de Biología. Departamento de Botanica; BrasilFil: Martins, Eliana R. Forni. Universidade Estadual Do Campinas. Instituto de Biología. Departamento de Botanica; BrasilFil: Urdampilleta, Juan Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Biologia floral e reprodução de Solanum paniculatum L. (Solanaceae) no estado de São Paulo, Brasil

Studies on floral biology and visitors were done over different years in two populations (Brotas and Campinas) of jurubeba, a common neotropical invader shrub. The flowers are dish-shaped and have a mellow odour. Pale-violet petals contrasting with yellow anthers make a visually attractive set. Pollen is the only reward for visitors. The species is alogamous. On average, 19% of the flowers in both populations had short styles; only long-styled flowers generated fruits, thus presenting a functional andromonoecism. Fruiting ratios in natural conditions differed between Brotas (43%) and Campinas (17%). The fruiting ratio due to manual polinization was 46% in Brotas and nihil in Campinas, this probably being due to a long dry period. Both microsporogenesis regularity and pollen high viability indicate that the process of sexual reproduction is normal. Poricide anthers and other flower features of S. paniculatum are associated with the buzz pollination syndrome, which requires bees with a specific behavior for pollen removal. The main pollinators are Oxaea flavescens, Bombus morio, and Xilocopa frontalis in the Campinas population, and Augochloropsis sp 1 e Augochloropsis sp 2 in the Brotas population.Estudos de biologia floral e dos animais visitantes, em anos diferentes, foram feitos em duas populações (Brotas e Campinas) de jurubeba, um arbusto invasor neotropical. As flores, do tipo aberto, têm odor muito suave. Pétalas de côr violeta-pálido, contrastando com as anteras amarelas, formam um conjunto visualmente atrativo. O pólen é a única recompensa para os visitantes. A espécie é alógama. Uma média de 19% das flores em ambas as populações apresentaram estilete curto e somente flores de estilete longo formaram frutos, indicando a existência de andromonoicia funcional. As taxas de frutificação em condições naturais diferiram entre Brotas (43%) e Campinas (17%). A frutificação por polinização manual foi de 46% em Brotas e nula em Campinas, provavelmente devido a um longo período de seca. A regularidade da microsporogênese e a alta taxa de viabilidade dos grãos de pólen mostraram a normalidade do processo de reprodução sexuada. Anteras poricidas e outras características florais de S. paniculatum estão associadas à síndrome da polinização vibrátil, que requer abelhas especializadas para a retirada de pólen. Os principais polinizadores foram Oxaea flavescens, Bombus morio, e Xylocopa frontalis na população de Campinas e Augochloropsis sp 1 e Augochloropsis sp 2 na de Brotas.11712

Chromosomal and morphological studies of diploid and polyploid cytotypes of Stevia rebaudiana (Bertoni) Bertoni (Eupatorieae, Asteraceae)

In this study, we examined the chromosome number and some morphological features of strains of Stevia rebaudiana. The chromosomes were analyzed during mitosis and diakinesis, and the tetrad normality and pollen viability were also assessed. In addition, stomata and pollen were measured and some plant features were studied morphometrically. All of the strains had 2n = 22, except for two, which had 2n = 33 and 2n = 44. Pairing at diakinesis was n = 11II for all of the diploid strains, whereas the triploid and tetraploid strains had n = 11III and n = 11IV, respectively. Triploid and tetraploid plants had a lower tetrad normality rate than the diploids. All of the strains had inviable pollen. Thus, the higher the ploidy number, the greater the size of the pollen and the stomata, and the lower their number per unit area. The triploid strain produced the shortest plants and the lowest number of inflorescences, whereas the tetraploid strain had the largest leaves. Analysis of variance revealed highly significant differences among the strains, with a positive correlation between the level of ploidy and all of the morphological features examined

Differences and resemblances in banding patterns and ribosomal DNA distribution in four species of Paullinieae tribe (Sapindaceae)

The tribe Paullinieae (Sapindaceae) is exclusively neotropically distributed, and is characterized by apomorphic characters and considered a monophyletic natural group. Recently explored cytogenetical aspects suggest that the disploid chromosomal reduction, the increase in the chromosomal size and the diversification of highly repetitive DNA sequences are associated with the karyotyp-ic evolution of this tribe. This work compares patterns of chromosome banding and the distribution of ribosomal DNA 18S-5.8S-26S in Cardiospermum grandiflorum Sw., Pullinia elegans Cambess., Urvillea chacoensis Hunz. and U. ulmacea Kunth. The studied species share the presence of a pattern of terminal C-Giemsa bands, differentiated for characteristics of heterochromatic regions. Terminal AT-rich bands occurred in C. grandiflorum (2n=2x=20) and U. chacoensis (2n=2x=22). Differing from the others, U. chacoensis presented prominent bands in the majority of chromosomes. The polyploid cytotype of U. ulmacea (2n=8x=88) possessed terminal bands CMA+ and DAPI+, forming heterochromatic blocks constituted by GC- and AT-rich repetitive DNA. On the other hand, P. elegans (2n=2x=24) presented a pattern of neutral bands after staining with CMA3/DAPI. The presence of GC-rich regions associated with 45S rDNA sites was a common characteristic in the studied species, nevertheless, variations in the NOR number might be useful for the differentiation of some species. Our results on karyological differences and resemblances of the studied species are discussed in relation to the systematics of the Paullinieae tribe. © 2008 The Japan Mendel Society.Fil: Urdampilleta, Juan Domingo. Universidade Estadual de Campinas; BrasilFil: Ferrucci, MarÍa Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Vanzela, André L. L.. Universidade Estadual de Londrina; BrasilFil: Forni Martins, Eliana R.. Universidade Estadual de Campinas; Brasi

Revisão taxonômica de Machaerium sect. Oblonga (Benth.) Taub. (Leguminosae, Papilionoideae, Dalbergieae)

RESUMO Na presente revisão taxonômica foram reconhecidas 12 espécies: M. floridum, M. goudoti, M. gracile, M. hatschbachii, M. myrianthum, M. nyctitans, M. obovatum, M. ovalifolium, M. ruddianum, M. saraense, M. scleroxylon e M. tortipes. Não foram reconhecidos táxons infra-específicos para M. nyctitans que teve sua circunscrição modificada. Foi proposto um nome novo, M. ruddianum, para M. floridum var. parviflorum. Foram também reconhecidos novos sinônimos para M. myrianthum e M. nyctitans e designado um epitipo para esta última espécie. As espécies da seção apresentam uma distribuição disjunta, com algumas espécies ocorrendo principalmente na Região Sudeste do Brasil e outras em países da região Amazônica e da América Central