Chen Wenchong, Yu Weiwu, Dong Ang, Zeng Yanru, Yuan Huwei, Zheng Bingsong, Wu Rongling
State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China.
Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.
Front Plant Sci. 2022 Jun 27;13:858187. doi: 10.3389/fpls.2022.858187. eCollection 2022.
Despite its high economical and ornamental values, , a dioecious non-timber coniferous species, has long been an underrepresented species. However, the advent and application of advanced genotyping technologies have stimulated its genetic research, making it possible to gain new insight into the genetic architecture of complex traits that may not be detected for model species. We apply an open-pollination (OP) mapping strategy to conduct a QTL mapping experiment of , in which nearly 100 unrelated trees randomly chosen from the species' natural distribution and their half-sib progeny are simultaneously genotyped. This strategy allows us to simultaneously estimate the recombination fractions and linkage disequilibrium (LD) coefficients between each pair of markers. We reconstruct a high-density linkage map of 4,203 SNPs covering a total distance of 8,393.95 cM and plot pairwise normalized LD values against genetic distances to build up a linkage-LD map. We identify 13 QTLs for stem basal diameter growth and 4 QTLs for stem height growth in juvenile seedlings. From the linkage-LD map, we infer the evolutionary history of and each of its QTLs. The slow decay of QTL-related LDs indicates that these QTLs and their harboring genomic regions are evolutionarily relatively young, suggesting that they can better utilized by clonal propagation rather than through seed propagation. Genetic results from the OP sampling strategy could provide useful guidance for genetic studies of other dioecious species.
尽管具有很高的经济价值和观赏价值，但作为一种雌雄异株的非木材针叶树种，长期以来一直是一个研究较少的物种。然而，先进基因分型技术的出现和应用推动了其遗传学研究，使得有可能对模型物种可能无法检测到的复杂性状的遗传结构获得新的见解。我们采用开放授粉（OP）作图策略对[物种名称]进行QTL作图实验，其中从该物种自然分布中随机选取近100株无关树木及其半同胞后代同时进行基因分型。这种策略使我们能够同时估计每对标记之间的重组率和连锁不平衡（LD）系数。我们构建了一个包含4203个SNP的高密度连锁图谱，总距离为8393.95 cM，并绘制成对标准化LD值与遗传距离的关系图以构建连锁-LD图谱。我们在幼苗中鉴定出13个控制茎基部直径生长的QTL和4个控制茎高生长的QTL。从连锁-LD图谱中，我们推断了[物种名称]及其每个QTL的进化历史。与QTL相关的LDs衰减缓慢表明这些QTL及其所在的基因组区域在进化上相对年轻，这表明它们通过克隆繁殖而非种子繁殖能得到更好的利用。来自OP采样策略的遗传结果可为其他雌雄异株物种的遗传研究提供有用的指导。
