Abstract Guarana, the fruit of Paullinia cupana, is known for its stimulating and medicinal properties by the Amazonian indigenous population and communities. However, it presents serious phytopathological problems, such as anthracnose disease caused by Colletotrichum spp. The objective of this study was to verify if C. siamense, a mycovirus-carrying endophytic fungus, could protect guarana seedlings, by reducing or by eliminating characteristic disease symptoms. Other physiological changes in the plant caused by the presence of this endophyte were also evaluated. The cuttings of the Cereçaporanga cultivar were dipped in a biological control suspension and planted in a specific substrate. After four months in the greenhouse, the seedlings were sprayed with a suspension of phytopathogen conidia, and a portion of these seedlings received the fungicide indicated for the crop to be compared with the control seedlings. After 28 days, the number of lesions, morphophysiological and macro characteristics, and leaf micronutrients were evaluated. The seedlings treated with C. siamense showed a lower percentage of lesions and an increased aerial part and root system compared to the other treatments. There were no significant differences between treatments regarding the percentage of macronutrients and micronutrients.

Abstract The objective of this study was to analyze the genetic diversity among and within populations of Brazil nut by Amplified Fragment Length Polymorphism markers. Five populations with 30 plants each of the state of Amazonas, Brazil, two populations from the Farm Aruanã (Aruanã Carolina and Aruanã Brastor), in Itacoatiara, one from the municipality of Parintins and two from the municipality of Manaus (Instituto Federal do Amazonas - IFAM and Manaus Airport) were evaluated. Four primer combinations were used and 306 polymorphic bands (93.3%) were obtained. Genetic differentiation within and among populations was tested by analysis of molecular variance. The presence of genetic divergence was greater within populations (51.88%) than among populations (48.11%) and the Fst value was 0.48. Two groups were formed by interpopulation grouping: the first consisted of populations from plantations in Aruanã Carolina, Aruanã Brastor and Manaus IFAM, and the second of natural populations from Parintins and Manaus Airport.

O trabalho objetivou caracterizar a diversidade genética de populações de buriti por meio de marcadores AFLP (Amplified Fragment Length Polymorphism). A análise foi realizada em quatro populações utilizadas por comunidades tradicionais do estado do Amazonas (Bom Jesus do Anamã, Lauro Sodré, Santa Luzia do Buiçuzinho e Esperança II). Foram amostrados aleatoriamente 30 indivíduos em cada população. Para a obtenção dos marcadores foram utilizadas quatro combinações de primers. Foi estimada a porcentagem de locos polimórficos, realizada análise de variância molecular entre e dentro de populações e construído dendograma. Os primers revelaram 339 locos polimórficos variando de 81,1 % a 91,1 % entre as populações. A Análise molecular de variância atribuiu 77,18 % de variação dentro e 22,82 % entre as populações. O dendograma revelou a formação de dois grupos, mostrando que as populações de Bom Jesus do Anamã e Lauro Sodré são as mais semelhantes geneticamente e que as distâncias genéticas não estão correlacionadas com a distância geográfica.

This study aimed to characterize the genetic diversity of buriti populations by AFLP (Amplified Fragment Length Polymorphism) markers. The analysis was performed in four populations used by traditional communities in the state of Amazonia (Bom Jesus do Anamã, Lauro Sodré, Santa Luzia do Buiçuzinho, and Esperança II). From each population 30 plants were randomly selected. To obtain the markers four primer combinations were used. The percentage of polymorphic loci was estimated, the molecular variance among and within populations analyzed and a dendrogram constructed. The primers detected 339 polymorphic loci ranging from 81.1 % to 91.1 % among populations. Analysis of molecular variance attributed 77.18 % to variation within and 22.8 % to variation between populations. The dendrogram indicated the formation of two groups, showing that the populations of Bom Jesus do Anamã and Lauro Sodré are genetically most similar and thet the genetic and geographical distances are not correlated.