Morphometric studies and analyses of germinability in Cenostigma macrophyllum Tul. in an urban-rural gradient in Teresina-PI, Brazil

Urbanization can alter environmental factors that affect the morphological and germinative characteristics of seeds. We evaluated the influence of an urban-rural gradient on the morphometrics of the fruits and seeds of Cenostigma macrophyllum Tul. (Fabaceae) and on seed germinability in the region near Teresina, Piaui State, Brazil. One hundred fruits were collected in the urban zone and 100 in the rural area, and the lengths, widths, thicknesses, and weights of both the fruits and seeds were measured, as well as the numbers of seeds per fruit. The seeds were then used in greenhouse germination experiments (during two months) to calculate the percentages of emergence (E%) and survival (S%), the emergence rate index (ERI), synchronization index (Z), and Timson’s index (T). The results showed significant statistical differences between the two areas in terms of the biometric patterns of the fruits and seeds as well as seed germination, with higher values in the urban zone. As such, urbanization was found to affect the morphologies and germination processes of plant species.