Analysis of the genetic structure and diversity of a Brazilian macadamia nut (Macadamia integrifolia) germplasm

Macadamia is a nut tree native to Australian rainforest. Due to the small wild populations and the economic interest, studies assessing genetic information are fundamental for use and conservation of this species. Therefore, the present study aimed to assess the structure and genetic diversity of 28 cultivars of macadamia originated from United States, Australia and Brazil, introduced or developed by the Agronomic Institute’s breeding program, using 29 new microsatellite loci. The microsatellite loci showed high genetic diversity (3.65 alleles per locus on average). Our results also suggested the existence of no genetic structure between cultivars, regardless of their geographic origin. The modified Rogers’ distances between cultivars ranged from 0.227 to 0.671. Despite the lack of information about genealogy, the cultivars from this Brazilian germplasm showed moderate genetic diversity, so they can be used as parents in future crosses.

Keywords:
Microsatellite; nut tree; cross-amplification; molecular marker; polymorphism