Wu Renzhi, Zou Peishan, Tan Guangwen, Hu Zhenyang, Wang Yongqi, Ning Zulin, Wu Wei, Liu Ying, He Shaoyun, Zhou Renchao
College of Forestry and Landscape Architecture South China Agricultural University Guangzhou China.
State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences Sun Yat-sen University Guangzhou China.
Ecol Evol. 2019 Apr 15;9(10):5766-5776. doi: 10.1002/ece3.5160. eCollection 2019 May.
Hybridization is very common in flowering plants and it plays a significant role in plant evolution and adaptation. L. (Melastomataceae) comprises about 80-90 species in tropical Asia and Oceania, among which 41 species occur in Borneo. Natural hybridization is frequently reported in in China, but so far there have been no confirmed cases of hybridization in Southeast Asia (including Borneo), where most species occur. Here, we identified a case of natural hybridization between L. and Cogn. in Sarawak, Malaysia, by using sequence data of three nuclear genes and one chloroplast intergenic spacer. is the most widespread species of this genus, occurring in almost the whole range of this genus, while is a local species endemic to northern Borneo. Our results showed that natural hybridization and introgression occur between and , and the introgression was asymmetrical, mainly from to . As adaptive traits can be transferred by introgression, our study suggests that natural hybridization should be a significant mechanism for the evolution and adaptation of in Southeast Asia. However, introgression from the common species to the relatively rare species may cause the decline of , incurring conservation concern. With a large number of species of and almost year-around flowering in Southeast Asia, more cases of natural hybridization are expected to be found and identified in near future.
杂交在开花植物中非常普遍，并且在植物进化和适应过程中发挥着重要作用。野牡丹科（Melastomataceae）的野牡丹属（Melastoma）在热带亚洲和大洋洲约有80 - 90个物种，其中41个物种分布在婆罗洲。在中国，经常报道有自然杂交现象，但到目前为止，在大多数物种分布的东南亚地区（包括婆罗洲）尚未有杂交的确切案例。在此，我们通过使用三个核基因和一个叶绿体基因间隔区的序列数据，在马来西亚砂拉越地区鉴定出了野牡丹属的展毛野牡丹（Melastoma normale）和科格纳野牡丹（Melastoma cogniauxianum）之间的一例自然杂交情况。展毛野牡丹是该属分布最广的物种，几乎分布于该属的整个分布范围，而科格纳野牡丹是婆罗洲北部特有的本地物种。我们的结果表明，展毛野牡丹和科格纳野牡丹之间发生了自然杂交和基因渐渗，并且基因渐渗是不对称的，主要是从展毛野牡丹到科格纳野牡丹。由于适应性性状可以通过基因渐渗转移，我们的研究表明自然杂交应该是东南亚地区野牡丹属植物进化和适应的一个重要机制。然而，从常见物种展毛野牡丹到相对稀有的物种科格纳野牡丹的基因渐渗可能会导致科格纳野牡丹数量减少，引发保护方面的担忧。由于东南亚地区有大量的野牡丹属物种且几乎全年开花，预计在不久的将来会发现和鉴定出更多自然杂交的案例。
