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 morphologicaland germinative characteristics of seeds. We evaluated the influence of anurban-rural gradient on the morphometrics of the fruits and seeds ofCenostigma macrophyllum Tul. (Fabaceae) and on seed germinability in theregion near Teresina, Piaui State, Brazil. One hundred fruits were collectedin 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 ingreenhouse germination experiments (during two months) to calculate thepercentages of emergence (E%) and survival (S%), the emergence rate index(ERI), synchronization index (Z), and Timson’s index (T). The results showedsignificant statistical differences between the two areas in terms of thebiometric patterns of the fruits and seeds as well as seed germination, withhigher values in the urban zone. As such, urbanization was found to affectthe morphologies and germination processes of plant species.