Carter Katherine A, Liston Aaron, Bassil Nahla V, Alice Lawrence A, Bushakra Jill M, Sutherland Brittany L, Mockler Todd C, Bryant Douglas W, Hummer Kim E
Department of Horticulture, Oregon State University, Corvallis, OR, United States.
Department of Botany & Plant Pathology, Oregon State University, Corvallis, OR, United States.
Front Plant Sci. 2019 Dec 20;10:1615. doi: 10.3389/fpls.2019.01615. eCollection 2019.
(Rosaceae) comprises more than 500 species with additional commercially cultivated raspberries and blackberries. The most recent (> 100 years old) global taxonomic treatment of the genus defined 12 subgenera; two subgenera were subsequently described and some species were rearranged. Intra- and interspecific ploidy levels and hybridization make phylogenetic estimation of challenging. Our objectives were to estimate the phylogeny of 94 taxonomically and geographically diverse species and three cultivars using chloroplast DNA sequences and target capture of approximately 1,000 low copy nuclear genes; estimate divergence times between major clades; and examine the historical biogeography of species diversification. Target capture sequencing identified eight major groups within . Subgenus and Subg. were monophyletic, while other recognized subgenera were para- or polyphyletic. Multiple hybridization events likely occurred across the phylogeny at subgeneric levels, e.g., Subg. (blackberries) × Subg. (raspberries) and Subg. × Subg. (Arctic berries) hybrids. The raspberry heritage within known cultivated blackberry hybrids was confirmed. The most recent common ancestor of the genus was most likely distributed in North America. Multiple distribution events occurred during the Miocene (about 20 Ma) from North America into Asia and Europe across the Bering land bridge and southward crossing the Panamanian Isthmus. species diversified greatly in Asia during the Miocene. taxonomy does not reflect phylogenetic relationships and subgeneric revision is warranted. The most recent common ancestor migrated from North America towards Asia, Europe, and Central and South America early in the Miocene then diversified. Ancestors of the genus may have migrated to Oceania by long distance bird dispersal. This phylogeny presents a roadmap for further systematics research. In conclusion, the target capture dataset provides high resolution between species though it also gave evidence of gene tree/species tree and cytonuclear discordance. Discordance may be due to hybridization or incomplete lineage sorting, rather than a lack of phylogenetic signal. This study illustrates the importance of using multiple phylogenetic methods when examining complex groups and the utility of software programs that estimate signal conflict within datasets.
蔷薇科包含500多个物种,还有商业化种植的树莓和黑莓。该属最近一次(超过100年历史)的全球分类处理定义了12个亚属;随后又描述了两个亚属,并对一些物种进行了重新排列。种内和种间的倍性水平以及杂交使得对其进行系统发育估计具有挑战性。我们的目标是利用叶绿体DNA序列和对大约1000个低拷贝核基因的靶向捕获来估计94个分类学和地理上不同的物种以及三个栽培品种的系统发育;估计主要分支之间的分歧时间;并研究物种多样化的历史生物地理学。靶向捕获测序在该属内确定了八个主要类群。亚属[具体亚属名称1]和亚属[具体亚属名称2]是单系的,而其他公认的亚属是并系或多系的。在系统发育的亚属水平上可能发生了多次杂交事件,例如,亚属[黑莓亚属名称]×亚属[树莓亚属名称]以及亚属[具体亚属名称3]×亚属[北极莓亚属名称]的杂交种。已知栽培黑莓杂交种中的树莓遗传成分得到了证实。该属最近的共同祖先很可能分布在北美洲。在中新世(约2000万年前)期间发生了多次分布事件,从北美洲通过白令陆桥进入亚洲和欧洲,并向南穿过巴拿马地峡。该属物种在中新世期间在亚洲大量分化。该属的分类并不反映系统发育关系,有必要进行亚属修订。最近的共同祖先在中新世早期从北美洲向亚洲、欧洲以及中美洲和南美洲迁移,然后分化。该属的祖先可能通过远距离鸟类传播迁移到了大洋洲。这个系统发育为进一步的该属系统学研究提供了路线图。总之,靶向捕获数据集在物种之间提供了高分辨率,尽管它也给出了基因树/物种树和细胞核 - 细胞质不一致的证据。不一致可能是由于杂交或不完全谱系分选,而不是缺乏系统发育信号。这项研究说明了在研究复杂类群时使用多种系统发育方法的重要性以及估计数据集中信号冲突的软件程序的实用性。