Horticulture Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456, USA.
Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
Int J Mol Sci. 2023 Feb 2;24(3):2904. doi: 10.3390/ijms24032904.
Poplar and willow species in the Salicaceae are dioecious, yet have been shown to use different sex determination systems located on different chromosomes. Willows in the subgenus are interesting for comparative studies of sex determination systems, yet genomic resources for these species are still quite limited. Only a few annotated reference genome assemblies are available, despite many species in use in breeding programs. Here we present de novo assemblies and annotations of 11 shrub willow genomes from six species. Copy number variation of candidate sex determination genes within each genome was characterized and revealed remarkable differences in putative master regulator gene duplication and deletion. We also analyzed copy number and expression of candidate genes involved in floral secondary metabolism, and identified substantial variation across genotypes, which can be used for parental selection in breeding programs. Lastly, we report on a genotype that produces only female descendants and identified gene presence/absence variation in the mitochondrial genome that may be responsible for this unusual inheritance.
杨属和柳属植物在杨柳科中是雌雄异株的，但它们被证明使用了位于不同染色体上的不同性别决定系统。在亚属中的柳树是性别决定系统比较研究的有趣对象，但这些物种的基因组资源仍然相当有限。尽管在育种计划中有许多物种在使用，但只有少数注释的参考基因组组装可用。在这里，我们展示了来自六个物种的 11 个灌木柳基因组的从头组装和注释。对每个基因组中候选性别决定基因的拷贝数变异进行了表征，揭示了假定主调控基因重复和缺失的显著差异。我们还分析了参与花次生代谢的候选基因的拷贝数和表达，发现了基因型之间的大量变异，这可用于育种计划中的亲本选择。最后，我们报告了一个只产生雌性后代的基因型，并鉴定了线粒体基因组中可能导致这种异常遗传的基因存在/缺失变异。
