Genetic diversity in natural populations of Stylosanthes scabra using ISSR markers

Genetic diversity is the basis for genetic improvement, providing genes for new cultivars. Stylosanthes scabra is a legume used in pastures, presenting economic importance in tropical and subtropical regions. Molecular markers are targeted in population studies, thus we evaluated the genetic diversity distribution of S. scabra in Brazilian semi-arid northeastern among and within populations, from molecular markers ISSR. Four natural populations of S. scabra located in the municipalities of Santa Cruz do Capibaribe, Floresta, Sertânia and Petrolina from Pernambuco state were used. We selected seven ISSR primers for amplification and analyzed 75 individuals. A total of 88 bands were amplified with a percentage of 95.27% polymorphism at the species level. AMOVA test revealed that 40.0% of the total genetic variation is within populations while 60.0% among populations. The population differentiation was 0.332 and the migrant’s number per generation was 0.5. Grouping analysis confirmed a high level of differentiation among populations. The populations with the greatest variability were Santa Cruz do Capibaribe and Petrolina, and the ISSR markers were efficient for the genetic diversity quantification in S. scabra, which presented greater variability among populations than within populations. In short, this variability will be very useful in future breeding programs for this species