Abstract:

In order to know genetic background of macadamia germplasms introduced, a genetic diversity analysis involving 64 accessions of Macadamia was performed using 41 morphological characteristics. Statistic analysis and R-style cluster analysis were used to examine the 41 morphological characteristics (including 19 quantitative traits and 22 qualitative traits) of macadamia based on the software DPSv7.05. The result showed: there were striking dissimilarity among characteristics; at the Euclidean distance approximately 11.72, the 41 characteristics were divided into two groups. There were significant differences among characteristics within their group. Most characteristics were independent one another and had important meaning in macadamia’s taxology. The result, based on Q-style cluster analysis, showed: Euclidean distance of 64 germplams ranging from 3.15 to 12.39, indicated high level of genetic diversity in these germplams. And the 64 germplams were divided into two groups at the Euclidean distance approximately 12. Group one included only T2，which belonged to related species of macadamia cultivation. Group two included the rest, which could be further divided into three sub-groups at the Euclidean distance approximately 10. The first sub-group included seven accessions: 695, 900, D4, HY, Guang9, Tet.-1, and Tet.-2, which belonged to hybrids of M.integrifolia and M. tetraphylla. The second sub-group included two accessions: A4 and A16, which also belongs to hybrids of M.integrifolia and M. tetraphylla, but were more similar to M. integrifolia. The third sub-group included the other 54 accessions that were all offsprings of M integrifolia. The cluster result, based on morphological characteristics analysis, was consistent with the existing system of taxology. Meanwhile, the blood relationship figure of 64 accessions was also obtained, and could be applied to combinations of cultivars, selection of hybrid parent and introduction from abroad.