Multi-level characterization of perennial cotton (Gossypium hirsutum L. race marie-galante Hutch.) populations from the northeastern Brazil to the breeding and conservation of this germplasm.

The remaining populations of perennial cotton (Gossypium hirsutum L. r. marie-galante Hutch.) that occur in northeastern Brazil are part of the primary gene pool for the creation of modern upland cotton cultivars. Therefore, we present fiber technological properties, genetic diversity and population structure analysis of four populations of G. hirsutum L. r. marie-galante from Para&305;´ba state in Brazil, using the High-Volume Instrument (HVI) analytical system and Inter Simple Sequence Repeats (ISSRs) polymorphic loci, respectively. The fiber technological properties differed between populations. The average length, resistance, micronaire index, maturity index and count-strength-product of the populations are consistent with the fiber quality traits present in commercial upland cotton cultivars. The populations showed low levels of total (HT= 0.1305) and intrapopulation (HS = 0.0806) genetic diversity, besides high genetic differentiation (GST= 0.3824) and low indirect gene flow (Nm = 0.875) and are structured in two gene clusters by Bayesian inference. The positive relationship between genetic distance and geographical distance using the Mantel test (r=0.8364; p value=0.0038) suggests that genetic divergence among populations can be explained by spatial isolation. This information can support genetic conservation and the valuation of these populations for cotton breeding programs