Population structure and genetic diversity in natural populations of Theobroma speciosum Willd. Ex Spreng (Malvaceae).

The genus Theobroma found in the Amazon region is composed of 22 species, including Theobroma speciosum, better known as cacauí. These species are constantly threatened by forest fragmentation caused by human activities and require conservation strategies and management aimed at preserving them in their natural environments. The main objective of this study was to analyze the population structure and genetic diversity within and between natural populations of T. speciosum by using ISSR molecular markers to understand the population structure of the species. Four natural populations belonging to the Amazon rainforest (BAC, CRO, FLA, and PNA), located in the State of Mato Grosso, were selected. Amplification reactions were performed using 15 ISSR primers. A total of 101 loci were found, of which 54.46% were polymorphic at the species level. The BAC population showed higher genetic diversity (H=0.095 and I=0.144) and higher percentage of polymorphism (28.71%). The populations showed an FST value of 0.604, indicating marked genetic differentiation. The highest genetic variation was found between populations. Gene flow was low between populations, indicating genetic isolation between populations.

Effect of crude extract of roots of Bredemeyera floribunda Willd. I. Effect on arterial blood pressure and renal excretion in the rat.

The infusion of the dried roots of Bredemeyera floribunda Willd. is used in Brazilian popular medicine as a potent diuretic, especially in the treatment of hypertension and nephrolithiasis (renal calculi). Intravenous administration of crude root-extract (20-80 mg/kg) to anesthetized rats induces clear dose-dependent and reversible hypotensive responses. At higher doses the extract leads to bradycardia and death. In doses that do not alter the arterial blood pressure, the extract elicited immediate and dose-dependent reversible increase of water, sodium, and potassium renal excretion. The results, apart from indicating that the renal effect of the extract is not due to its systemic hypotensive action, support the folk therapeutic use of the infusion of the root-extract as a diuretic.