-The objective of this work was to characterize the populations of Gossypium barbadense in the states of Amapá and Pará, Brazil. In situ characterization was conducted through interviews with the owners of the plants and environmental observations. Leaf or petal tissue as well as seed samples were collected for genetic characterization by single sequence repeats markers and for storage in germplasm banks, respectively. The plants were maintained in dooryards and used mainly for medical purposes. The genetic analysis showed no heterozygous plants at the loci tested (f = 1), indicating that reproduction occurs mainly through selfi ng. The total genetic diversity was high (H e = 0.39); and a high level of differentiation was observed between cotton plants from the two states (F ST = 0.36). Conventional methods of in situ maintenance of G. barbadense populations are not applicable. The conservation of the genetic variability of populations present in the two states could be achieved through germplasm collection and establishing of ex situ seed banks.Index term: cotton, genetic diversity, germplasm, SSR markers. Caracterização in situ e genética de Gossypium barbadense dos Estados do Pará e do AmapáResumo -O objetivo deste trabalho foi caracterizar populações de Gossypium barbadense dos estados do Amapá e Pará. A caracterização in situ foi conduzida por meio de entrevistas com os proprietários das plantas e por observações sobre o ambiente. Tecidos de folhas ou de pétalas, além de sementes, foram coletados para a caracterização genética com marcadores SSR ("single sequence repeats") e para o armazenamento em bancos de germoplasma, respectivamente. As plantas eram mantidas em fundos de quintal e usadas, principalmente, para fi ns medicinais. As análises genéticas não mostraram plantas heterozigotas nos locos testados (f = 1), o que indica que a reprodução ocorre principalmente por meio de autofecundação. A diversidade genética total foi alta (H e = 0,39), e um alto nível de diferenciação foi observado entre as plantas de algodoeiro dos dois estados (F ST = 0,36). Métodos convencionais para a manutenção in situ das populações de G. barbadense não são aplicáveis. A conservação da variabilidade genética das populações presentes nos dois estados deve ser realizada pela coleta de germoplasma e pela constituição de bancos de sementes ex situ.Termos para indexação: algodoeiro, diversidade genética, germoplasma, marcadores SSR.

-The objective of this work was to identify polymorphic simple sequence repeat (SSR) markers for varietal identification of cotton and evaluation of the genetic distance among the varieties. Initially, 92 SSR markers were genotyped in 20 Brazilian cotton cultivars. Of this total, 38 loci were polymorphic, two of which were amplified by one primer pair; the mean number of alleles per locus was 2.2. The values of polymorphic information content (PIC) and discrimination power (DP) were, on average, 0.374 and 0.433, respectively. The mean genetic distance was 0.397 (minimum of 0.092 and maximum of 0.641). A panel of 96 varieties originating from different regions of the world was assessed by 21 polymorphic loci derived from 17 selected primer pairs. Among these varieties, the mean genetic distance was 0.387 (minimum of 0 and maximum of 0.786). The dendrograms generated by the unweighted pair group method with arithmetic average (UPGMA) did not reflect the regions of Brazil (20 genotypes) or around the world (96 genotypes), where the varieties or lines were selected. Bootstrap resampling shows that genotype identification is viable with 19 loci. The polymorphic markers evaluated are useful to perform varietal identification in a large panel of cotton varieties and may be applied in studies of the species diversity.Index terms: Gossypium hirsutum, cultivar discrimination, intraspecific polymorphism, microsatellite. Uso otimizado de marcadores SSR para identificação varietal de algodoeiro herbáceoResumo -O objetivo deste trabalho foi identificar marcadores polimórficos de sequências simples repetidas (SSR) para identificação varietal de algodão e avaliação da distância genética entre as variedades. Inicialmente, 92 marcadores SSR foram genotipados em 20 cultivares de algodão do Brasil. Desse total, 38 locos foram polimórficos, dos quais dois deles foram amplificados por um único par de iniciadores; o número médio de alelos por loco foi 2,2. Os conteúdos de informação polimórfica (PIC) e de poder de discriminação (DP) foram, em média, 0,374 e 0,433, respectivamente. A distância genética média foi de 0,397 (mínima de 0,092 e máxima de 0,641). Um painel de 96 variedades originárias de diversas regiões do mundo foi avaliado por 21 locos polimórficos derivados a partir de 17 pares de iniciadores selecionados. Entre essas variedades, a distância genética média foi de 0,387 (mínima de 0 e máxima de 0,786). Os dendrogramas elaborados a partir de média aritmética não ponderada (UPGMA) não refletiram as regiões do Brasil (20 genótipos) ou do mundo (96 genótipos), onde as variedades ou linhagens foram selecionadas. O procedimento de reamostragem bootstrap mostra que a identificação dos genótipos é viável com 19 locos. Os marcadores polimórficos avaliados são úteis na identificação varietal de um painel amplo de variedades de algodão e podem ser aplicados em estudos de diversidade da espécie.Termos para indexação: Gossypium hirsutum, discriminação de cultivares, polimorfismo intraespecífico, microssatélite.

Lisianthus is an important ornamental species, whose cultivation in pot still requires studies, mainly regarding the use of alternative management. Thus, the aim of this work was to evaluate the influence of resistance elicitors on the production and post-production quality of potted lisianthus. Plants grown in pots were treated with two elicitors: (E1) phosphorylated mannano-oligosaccharide and (E2) citric bioflavonoids and phytoalexins, in the doses (D) of 1 and 2pL.L-1 (E1D1 1pL.L-1, E1D2 2pL.L-1, E2D1 1pL.L-1, E2D2 2pL.L-1 and control), with 5 replications, in a completely randomized design. After opening the first flower buds, the plants remained in the greenhouse for 15 days, until they reached at least 3 open flowers, when were transferred to the room conditions (24 ± 2 oC and 72 ± 2%) for another 15 days. The application of elicitors did not influence the culture cycle or the size of the stem. There was an increase, however, in the number of viable buds and open flowers, in addition to an increase in flower’s useful life paralleled to the reduction of senescent flowers, in relation to the control. The dose of 2pL.L-1 of the E2 kept the percentage of viable open flowers in relation to the control for at least another 5 days, reducing the percentage of senescent flowers. Together, with the application of the E2 elicitor in potted lisianthus, the viability of the flowers can be prolonged, maintaining quality and delaying senescence, and, in this way, increasing the market period.

Considering the importance of identifying Colletotrichum species associated with cotton plants, this study aimed to characterize the morphological and pathogenic isolates of C. gossypii var. cephalosporioides and C. gossypii under different temperatures. Five isolates of C. gossypii var. cephalosporioides and C. gossypii were incubated at 20, 25 and 30 °C. The cultural characteristics data were analyzed through ANOVA and the means compared by the Tukey test. There were differences between the isolates of the two species concerning mycelial growth and sporulation at different temperatures. Temperatures between 20 to 30 °C increased the length of conidia but did not influence the width, whereas between 25 and 30 °C, there was the highest mycelial growth. Colletotrichum gossypii expressed anthracnose symptoms, and ramulosis symptoms were observed only in plants inoculated with C. gossypii var. cephalosporioides.