O gênero Inga (Leguminosoe, Mimosoideae) no Nordeste do Brasil: citogenética, taxonomia e tecnologia de sementes

Abstract

Inga striata Benth. is a native Brazilian tree that grows in tropical and gallery forests and is distributed in the Antilles, and tropical South America and Bolivia. In Brazil this species occurs in the Amazon, in the northeastern region, and in Minas Gerais State. It is used in the recuperation of soils in degraded areas, as a fruit tree, and in urban landscaping. The present work sought to determine the best indices of seed maturity and the ideal time to harvest them by evaluating their physiological quality during maturation. The experiments were performed between Novembro/2006 and Abril/2007 and in Novembro/2007 and May/2008 in an altitudinal forest on Campus II of the Federal University of Paraíba (UFPB), in Areia, Paraíba State, Brazil. The treatments consisted of six different times of fruit harvesting after anthesis (95, 110, 125, 140, 155 and 170 days after anthesis), during two different periods of observations, utilizing all of the possible combinations (a 2 x 6 factorial scheme). During each harvest the dimensions of the fruits and seeds were evaluated, as well as their water content, seed dry weight, and germination and vigor (first germination count, germination velocity index, and the length and dry weight of the primary root and aerial shoot). The results indicated that, for the study area, I. striata demonstrated same periods of fruiting not differing periods of fruit maturation during the two study periods, with the seeds reaching physiological maturity in 156 days after anthesis in the first assessment s periods and after 155 days in the second year. The principal indices of maturity were seed size, water content, dry weight, germination capacity of seeds, and the dry weight of the aerial portion of the seedlings. Harvesting of the fruits should be performed 155 days after anthesis, with fruits having a green color and only beginning to initiate seed dispersal.