Science and Technology Daily (Reporter Wang Zhuhua and Intern Xie Zhuo)
On October 12, the reporter learned from Hainan University that Xia Zhiqiang's team from the university has deciphered the macadamia nut genome and annotated it, which findings were recently published in the Chinese Journal of Tropical Crops.
Macadamia ternifolia, also known as macadamia nuts, Queensland fruit, is a tree nut native to Australia, which contains more than 70% fat, 9% protein, and 8 kinds of amino acids essential to human body. Because of its nuts taste crispy and rich in a variety of unsaturated fatty acids, it has a very high nutritional and health care value, so it often appears in the shopping list of people all year round.
Xia Zhiqiang's team constructed a chromosome-level macadamia nut genome (792Mb Contig N50 1.9Mb) through three-generation sequencing of "Guire 1", the earliest new variety of macadamia nut with independent intellectual property rights in China. The team also identified 37,657 coding proteins through gene prediction from scratch and homologous protein comparisons. The researchers analyzed macadamia nuts for gene families with 11 species and used single-copy genes to construct a phylogenetic tree, which found that macadamia nuts were diverged from the same family of Telopea speciosissima about 71 million years ago. Furthermore, macadamia nuts underwent a WGD (Whole-genome doubling) incident 41 million years ago. The study also identified 120 members of the GELP (GDSL-type lipase) gene family and determined their locations on 14 chromosomes.
It is reported that the results of this research provide new resources for macadamia nut genomics research and molecular marker breeding, and bring more opportunities for macadamia nut genetic and evolutionary research in the future. The genomic information of macadamia nuts also helps to elucidate the evolutionary process of proteaceae species and to further our understanding of the physiological and morphological diversity of proteaceae species, hence revealing the important role of macadamia nuts in the evolutionary history.