Caracterização morfoanatômica, fenológica, pós-colheita e produtiva do cambuí (Myrciaria floribunda (H. West ex Willd.) O. Berg)

Abstract

Myrciaria floribunda (H. West ex Willd.) O. Berg, popularly known as cambuí, camboim or jabuticabinha, is a fruit species distributed throughout Brazil and, in the state of Alagoas, it occurs naturally in coastal regions and restingas. Despite its extractive exploitation, its fruits have been gaining commercial interest thanks to the variety of flavors and the richness in antioxidant compounds, such as anthocyanins, carotenoids, flavonoids, and vitamin C. Despite the increase in interest for native fruits like cambuí, commercial scale production with high quality is only possible through study, selection and improvement aiming the domestication of these plant species. The objective of this work was to study the morphoanatomy and floral biology, reproductive phenology, morphological characterization and productive analysis in cambuí accessions in order to provide information that can guide the improvement of the species. The research was conducted at the Active Bank of Cambuí Germplasm (BAG-Cambuí) of the Campus of Engineering and Agricultural Sciences, Federal University of Alagoas (CECA/UFAL) in Rio Largo, Alagoas. For the study of floral biology 145 accessions were selected and evaluated for stigma receptivity, pollen grain viability, anthesis determination and floral visitors; for floral morphoanatomy observations were made under light microscope and scanning microscopy (SEM) of flower morphoanatomical structures from bud emergence to anthesis. In the reproductive phenology study, flowering and fruiting events were observed every 7 days and correlated to meteorological records. For the morphological characterization of the plants (accessions), 9 quantitative descriptors and 14 qualitative descriptors were used, whose data were used in a grouping test to obtain a dendrogram. For the productive analysis the accessions were evaluated in three harvests, when post-harvest evaluations of the fruits were made, such as fruit weight (FP), seed weight (PS), number of seeds per fruit (NS), pulp firmness (F), pulp yield longitudinal diameter (LD) and transverse diameter (TD), total soluble solids (TSS) and total titratable acidity (TTA), ratio (TSS/TA ratio), thousand seed weight, thousand fruit weight and total fruit weight per access and estimated number of fruits per access. The results showed that Apis mellifera and Trigona spinipes are the main floral visitors of cambuí. Regarding the receptivity of the stigma, it was possible to note that it remains viable for a period of up to 5 h after opening the flower; the flower begins to senesce after 48 h; the pollen grain has a triangular shape, measuring on average 11 μm and viability above 90%. Regarding the reproductive phenology it was possible to observe that the accessions evaluated bloom irregularly almost the entire year with the exception of the hottest and driest months of the year. In general, the plants concentrate the flowering in two periods of the year with major peaks in March and August, while the highest peaks of fruiting were observed in April and September. The quantitative morphological analysis showed great variability among the accessions, especially for plant height, which varied from 0.78 m and 2.58 m for plants that were 9 years old, indicating different growth potentials and vegetative vigor. The cluster analysis indicated the formation of homogeneous groups, especially group 2 of quantitative characterization, which was formed by 12 accessions with higher means of plant height (2.23 m), crown insertion height (0.42 m), crown length (1.80 m), crown diameter (2.06 m), height of the first fork (0.43 m), stem diameter at 10 cm from the ground (0.50 m) and crown proportion (81.11%). The qualitative characterization indicated that 74.48% of the accessions have rounded crown, with medium to high crown density, with percentage of 39.31% and 57.24% of the accessions respectively. The Tocher optimization analysis indicated that the protrusion index and crown proportion were the variables that contributed most to the formation of the quantitative groups and that the crown architecture (16.60%) was the variable that contributed most to the formation of the qualitative groups. The postharvest characterization of the fruit showed that the accessions AC52 and AC140 stood out with respect to PF, with 1.009 g and 1.059 g, respectively. Accession AC52 also stood out in PF, NS, F, DL and DT, while AC140 obtained the lowest value for fruit firmness (3.353 N). The access AC08 presented the lowest PF (0.359 g) and the lowest PS (0.072 g). The access AC02 showed lower NS (1.0), and with respect to fruit firmness the highest value was observed in access AC107 (5.207 N), the access AC33 (26.40 oBrix) and AC11 (25.63 oBrix) showed higher content of TSS, access AC11 also showed higher value of ratio (6.53). with respect to postharvest attributes observed in the different harvests, it was possible to highlight the harvest 1 that showed higher FP (0.647 g), higher PS (0.171 g), higher NS (1.32), higher DL (9.557 mm) and higher DT (8.647 mm). Regarding the productive analysis, the accessions AC107 and AC52 presented the highest total weight of the fruits with 5.2 kg and 5.01 kg, respectively. Regarding the estimation of the number of fruits per plant, AC63 stood out with 12,464 fruits. Regarding the evaluation of harvests, harvest 3 presented the highest yield of pulp and differed statistically from the others, and regarding the number of fruits per plant, harvest 1 presented the worst result. There was no statistical difference regarding the total. Keywords: native plants, restinga, plant improvement.