Caracterização morfo-física de frutos e curva de embebição de sementes da Bertholletia excelsa Humb. & Bonpl.

Abstract

In this study characterized biometrically the fruits and seeds and was determined the duration of Phase I of the imbibition curve of Bertholletia excelsa Humb. & Bonpl. seeds for White and Pink genotypes at diferents temperatures and size classes. Samples were collected in native forest in the municipalities of Claudia and Itaúba - Mato Grosso, in the months of October, November and December 2014 (collect 1, 2 and 3) and March 2015 (collect 4). It demarcated 15 trees have been measured its diameter at breast height (m), crown diameter (m), commercial height and total (m). A total of 1,019 fruits were collected and subjected to biometric analysis: equatorial and longitudinal diameter (cm); thickness exocarp and mesocarp (mm); mass of the fruit and seeds per fruit (g); number of fruits per plant and number of seeds per fruit. Measured mass (g) and equatorial diameters (1; 2) and longitudinal (mm) of 750 seeds. Biometric data were submitted to descriptive statistics, Tukey Test and Pearson’s Correlation (5% of probability). The imbibition curve determined two size classes (Class I and Class II) and moisture contente in oven at ±105°C until reach the constant mass. The nuts passed aseptic and fungal treatment, and were conditioned in germination chambre at temperatures of 25 to 30°C and 12 hour photoperiod. Each seed was weighed just a repetition during 20 days the each 8 hours, featuring a 2x2x2 factorial (genotype x temperatura x class). The dimensions of the fruits and seeds of the Castanheira of Pink genotype are larger that of White. Biometric standard of seeds Pink genotype were (CI 1,705 – 2,953 g; CII 2,953 – 4,202 g) and the White genotype (CI 2,008 – 2,671 g; CII 2,671 – 3,335 g). The duration of Phase I in the imbibition of seeds is smaller in the White. The temperature of 30ºC accelerates the transition of Phase I to Phase II of the species Bertholletia excelsa seeds during the imbibition of the germination process.