Fotoperíodo na germinação de sementes de Senegalia bahiensis (Benth.) Seigler & Ebinger

Abstract

Given the great diversity of species in the Caatinga, related to seed technology studies are of utmost importance in order to preserve and develop protocols that allow composing seed lots. Thus, the aim of this study was to evaluate the influence of photoperiod on germination Senegalia bahiensis, kind of a big occurrence in Caatinga belonging to family Fabaceae. The experiment was conducted in the Laboratory of Physiology, Federal University of Reconcavo of Bahia, Cruz das Almas - Bahia. Seeds from fruits collected from 14 trees Senegalia bahiensis arrays were used. We used a completely randomized design (CRD) in factorial 3 x 14, fourteen arrays and three photoperiods (8 hours, 12 hours and continuous light), totaling 42 treatments with three repeat 25 seeds. Determined the percentage of germination of normal seedlings (% G), average root length based on the total number of seeds (CR / NS) and the index of germination speed (IVG). Data were subjected to analysis of variance and means were compared by Tukey test at 5% probability. To study the genetic diversity of seed trees for phenotypic traits (germination percentage, speed of germination Index, normal seedling dry weight, root length, shoot length, total length, root and shoot ratio, weight of 1000 seeds, number of seeds in 100 fruits, fruit weight of 100) was used to Mahalanobis distance. The definition of the number of groups formed in the cluster analysis was determined by the index of Duda. The time of exposure to light is not a limiting factor germination of this species, though generally the 8-hour photoperiod provided better performance for most matrices with respect to the study variables. The different matrices showed different behavior with respect to a preference for photoperiods. Given this result suggests considering this difference in the composition of seed lots, in order to ensure homogeneity within the lots, the M4 and M13 (8 hours and 12 hours) and M5 (12 hours) with its particularities.