Lin Qianhui, Hu Siqi, Wu Zhenhua, Huang Yahui, Wang Shuo, Shi Wenbo, Zhu Bingyue
College of Biological Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
Sci Rep. 2025 Apr 17;15(1):13291. doi: 10.1038/s41598-025-95789-y.
Actinidia species are fruit trees with various functions, such as providing edible fruit, serving as ornamental plants, and having medicinal benefits. However, the taxonomy of Actinidia species is controversial due to widespread hybridization, the history of divergence and polyploid speciation among Actinidia species also remains unclear. In this study, we conducted comparative analyses of the chloroplast genomes and ploidy among multiple Actinidia species. The genes clpP, infA, ndhD, ndhK, and rpl20 were absent from these chloroplast genomes. The ycf2 and rpl20 genes in the Actinidia species were under positive selection. Several regions (rps16-trnQ-UUG, trnS-GCU-trnR-UCU, ndhC-trnV-UAC, rbcL-accD, rps12-psbB, trnN-GUU-ndhF, ycf1-trnN-GUU, and trnH-GUG-psbA) and genes (ycf1, ycf2, accD, rpl20) exhibited high variability, which could potentially serve as molecular markers in species delineation and other phylogenetic studies. Through divergence time estimation, the Actinidia genus originated 23 million years ago (Ma), and experienced a tetraploidization event in ~ 20 Ma. Subsequently, Actinidia has undergone extensive diploidization. Our findings will provide valuable information in species identification, breeding programs, and conservation efforts for Actinidia species.
猕猴桃属植物是具有多种功能的果树，如提供可食用的果实、作为观赏植物以及具有药用价值。然而，由于广泛的杂交，猕猴桃属植物的分类存在争议，猕猴桃属物种之间的分歧历史和多倍体物种形成也仍不清楚。在本研究中，我们对多个猕猴桃属物种的叶绿体基因组和倍性进行了比较分析。这些叶绿体基因组中缺少clpP、infA、ndhD、ndhK和rpl20基因。猕猴桃属物种中的ycf2和rpl20基因受到正选择。几个区域（rps16-trnQ-UUG、trnS-GCU-trnR-UCU、ndhC-trnV-UAC、rbcL-accD、rps12-psbB、trnN-GUU-ndhF、ycf1-trnN-GUU和trnH-GUG-psbA）和基因（ycf1、ycf2、accD、rpl20）表现出高变异性，这可能在物种划分和其他系统发育研究中作为分子标记。通过分歧时间估计，猕猴桃属起源于2300万年前（Ma），并在约20Ma时经历了一次四倍体化事件。随后，猕猴桃经历了广泛的二倍体化。我们的研究结果将为猕猴桃属物种的鉴定、育种计划和保护工作提供有价值的信息。
