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Camu-camu (Myrciaria dubia), a fruit from the Amazon region, has received attention due to its high content of antioxidant compounds such as ascorbic acid and polyphenols. This study's objective was to select camu-camu clones according to their morphological characteristic using multivariate analyses. We evaluated 56 camu-camu clones distributed in three blocks with two plants per experimental plot. The variables measured were plant height (H), number of basal branches (NBB), number of terminal buds (NTB), basal stem diameter (BSD), chlorophylls a (Chl a) and b (Chl b), and total chlorophyll (Chl a + b). Principal component (PCA) and multivariate clustering analyses were performed using the average linkage mean and Mahalanobis distance algorithms. After 24 months, results showed that the characteristic that least contributed to clone selection was NBB. The plant height (H), number of terminal buds (NTB), basal stem diameter (BSD), chlorophylls a (Chl a) and b (Chl b), and total chlorophyll (Chl a + b) had the most positive contribution towards the initial selection of camu-camu clones at two years of age. The 22 camu-camu clones showed the highest rate of vegetative development or vegetative quality index (VQI) in the transitional savanna/forest area of the northern Amazon, Brazil, after two years of transplanting. RESUMEN El camu-camu (Myrciaria dubia) es una fruta de la región amazónica que ha recibido atención debido a su alto contenido de compuestos antioxidantes, como el ácido ascórbico y los polifenoles. El objetivo del estudio fue seleccionar clones de camu-camu según sus características morfológicas mediante análisis multivariados. Se evaluaron 56 clones de camu-camu distribuidos en tres bloques con dos plantas por parcela experimental. Las variables medidas fueron altura de la planta (H), número de ramas basales (NRB), número de brotes terminales (NBT), diámetro basal del tallo (DT), clorofila a (Chl a) y b (Chl b) y clorofila total (Chl a + b). Los análisis de agrupamiento de componentes principales (PCA) y multivariados se realizaron utilizando la media de enlace y los algoritmos de distancia de Mahalanobis. Después de 24 meses, los resultados mostraron que la característica que menos contribuyó a la selección del clon fue el NRB. La altura de la planta, número de ramas basales (NRB), diámetro basal del tallo (DBT), clorofila a (Chl a) y b (Chl b) y clorofila total (Chl a + b) tuvieron la contribución más positiva hacia la selección inicial de clones de camu-camu a los dos anos de edad. Veintidós clones de camu-camu presentaron la mayor tasa de desarrollo vegetativo o índice de calidad de la vegetación (ICV) en la sabana de transición/área forestal del norte del Amazonas, Brasil, después de dos anos de trasplante.

The study aimed to verify the physiological quality of seeds of Myrciaria dubia, stored for 300 days in different conditions and packaging, using tests of electrical conductivity and seedling vigour. The seeds were classified into three weight classes (small, medium and large). Small seeds were considered those with a weight of less than 0.84 g, medium seeds with a weight between 0.86 g and 1.20 g, and large seeds, a weight of greater than 1.22 g. The seeds were stored in glass containers and plastic pots topped up with water, in the laboratory at a room temperature of 23 to 25°C and relative humidity of 60-70%, and in a cold chamber at a temperature of 14-16°C and relative humidity of 50-60%. For each storage period (0, 30, 60, 120, 180, 240 and 300 days), a sample of 110 seeds was used for analyses, including imbibition curve, seed dry weight, electrical conductivity, seedling emergence and emergence speed index. The responses of the seeds in both the laboratory and cold-chamber, and stored in plastic pots topped up with water, are indicated for maintaining physiological quality and seedling vigour up to 300 days., Revista de Ciências Agrárias, Vol. 44 N.º 2-3 (2021)

The study aimed to verify the physiological quality of seeds of Myrciaria dubia, stored for 300 days in different conditionsand packaging, using tests of electrical conductivity and seedling vigour. The seeds were classified into three weight classes (small,medium andlarge). Small seeds were considered those with a weight of less than 0.84 g, medium seeds with a weight between 0.86 g and 1.20 g, and large seeds, a weight of greater than 1.22 g.The seeds were stored in glass containers and plastic pots topped up with water, in the laboratory at a room temperature of 23 to 25°C and relative humidity of 60-70%, and in a cold chamber at a temperature of 14-16°C and relative humidity of 50-60%. For each storage period (0, 30, 60, 120, 180, 240 and 300 days), a sample of 110 seeds was used for analyses, including imbibition curve, seed dry weight, electrical conductivity, seedling emergence and emergence speed index. The responses of the seeds in both the laboratory and cold-chamber, and stored in plastic pots topped up with water, are indicated for maintaining physiological quality and seedling vigour up to 300 days., The study aimed to determine the physiological quality of seeds of Myrciaria dubia, stored for 300 days in different conditions and packaging, using tests of electrical conductivity and seedling vigour. The seeds were classified into three weight classes (small, medium and large). Small seeds were considered those with a weight of less than 0.84 g, medium seeds with a weight between 0.86 g and 1.20 g, and large seeds, a weight of greater than 1.22 g. The seeds were stored in glass containers and plastic pots topped up with water, in the laboratory at a room temperature of 23 to 25°C and relative humidity of 60-70%, and in a cold chamber at a temperature of 14-16°C and relative humidity of 50-60%. For each storage period (0, 30, 60, 120, 180, 240 and 300 days), a sample of 110 seeds was used for analyses, including imbibition curve, seed dry weight, electrical conductivity, seedling emergence and emergence speed index. According to the results obtained, the responses of the seeds in both the laboratory and cold-chamber, and stored in plastic pots topped up with water, were indicated for maintaining physiological quality and seedling vigour up to 300 days.