Phenotypic Characterisation for Growth and Nut Characteristics Revealed the Extent of Genetic Diversity in Wild Macadamia Germplasm

Macadamia is a recently domesticated Australian native nut crop, and large proportion of its wild germplasm unexploited. Aiming to explore the existing diversity, 247 accessions from four species inter-specific hybrids were phenotyped. A wide range variation was found in growth traits. Broad-sense heritability traits moderate (0.43–0.64), which suggested that both genetic environmental factors are equally important for variability Correlations among significantly positive (0.49–0.76). There significant correlations except kernel recovery. The association between recovery shell thickness highly negative. Principal component analysis separated representative groups. Accessions integrifolia Maiden Betche, M. tetraphylla L.A.S. Johnson, admixtures clustered into one group those ternifolia F. Muell another group. In groups, within site greater than across sites, conservation strategies should concentrate on increased sampling sites capture diversity. This study provides background utilisation as resource be used breeding programs direction gene pool conservation.