Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0028, South Africa.
College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931-1295, USA.
G3 (Bethesda). 2022 Apr 4;12(4). doi: 10.1093/g3journal/jkac004.
Terpenes are an important group of plant specialized metabolites influencing, amongst other functions, defence mechanisms against pests. We used a genome-wide association study to identify single nucleotide polymorphism (SNP) markers and putative candidate genes for terpene traits. We tested 15,387 informative SNP markers derived from genotyping 416 Eucalyptus grandis individuals for association with 3 terpene traits, 1,8-cineole, γ-terpinene, and p-cymene. A multilocus mixed model analysis identified 21 SNP markers for 1,8-cineole on chromosomes 2, 4, 6, 7, 8, 9, 10, and 11, that individually explained 3.0%-8.4% and jointly 42.7% of the phenotypic variation. Association analysis of γ-terpinene found 32 significant SNP markers on chromosomes 1, 2, 4, 5, 6, 9, and 11, explaining 3.4-15.5% and jointly 54.5% of phenotypic variation. For p-cymene, 28 significant SNP markers were identified on chromosomes 1, 2, 3, 5, 6, 7, 10, and 11, explaining 3.4-16.1% of the phenotypic variation and jointly 46.9%. Our results show that variation underlying the 3 terpene traits is influenced by a few minor loci in combination with a few major effect loci, suggesting an oligogenic nature of the traits.
萜类化合物是植物中一类重要的特殊代谢物，它们除了其他功能外，还影响植物对害虫的防御机制。我们使用全基因组关联研究来鉴定单核苷酸多态性 (SNP) 标记和萜类化合物性状的候选基因。我们测试了来自 416 个巨桉个体的 15387 个信息性 SNP 标记与 3 个萜烯性状（1,8-桉叶素、γ-松油烯和对伞花烃）的关联。多基因混合模型分析在染色体 2、4、6、7、8、9、10 和 11 上鉴定出了 1,8-桉叶素的 21 个 SNP 标记，这些标记分别解释了 3.0%-8.4%和联合解释了 42.7%的表型变异。γ-松油烯的关联分析发现，在染色体 1、2、4、5、6、9 和 11 上有 32 个显著的 SNP 标记，解释了 3.4-15.5%和联合解释了 54.5%的表型变异。对于对伞花烃，在染色体 1、2、3、5、6、7、10 和 11 上鉴定出了 28 个显著的 SNP 标记，解释了 3.4-16.1%的表型变异和联合解释了 46.9%。我们的结果表明，这 3 种萜烯性状的变异是由少数微效基因与少数主效基因共同作用的结果，这表明这些性状具有寡基因遗传的性质。
