Hybrid origins and F1 dominance in the freefloating sterile bladderwort, Utricularia australis F. Australis (Lentibulariaceae)
Hybrid origins and F1 dominance in the freefloating sterile bladderwort, Utricularia australis F. Australis (Lentibulariaceae)
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DOI：
10.3732/ajb.92.3.469
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发表时间：
2005-03-01
影响因子：
3
通讯作者：
Ohara, M
中科院分区：
文献类型：
--
作者：
Kameyama, Y;Toyama, M;Ohara, M
放弃有性生殖是水生植物的一个众所周知的特征，而不育的原因、程度和后果往往是未知的。摘要austrularia australis f. australis （Lentibulariaceae）是一种自由漂浮的不育狸藻，广泛分布于温带和热带地区。栽培条件下的实验杂交、AFLP分析和自然群体的cpDNA单倍型分析清楚地表明，南方南方南方南方南方南方南方南方南方南方是由两个亲本类群（以雌性为主）和以雄性为主)的不对称杂交而来。利用AFLP条带的加性模式结合广泛不育性的观察，未检测到f后杂种。反复杂交和随后的无性繁殖通过独特的，但单态的，AFLP基因型观察到每个南方南方稻居群。杂交种与亲本种不共存，表明杂交种在一定的环境条件下具有优势。目前尚不清楚的是，美国南方南方的种群是通过殖民化繁殖体维持的，还是作为过去杂交事件的遗迹。
Abandonment of sexual reproduction is a well-known characteristic in aquatic plants, while the causes, levels, and consequences of sterility are often unknown. Utricularia australis f. australis (Lentibulariaceae) is a free-floating, sterile bladderwort distributed widely in temperate and tropical regions. Experimental crosses in cultivated conditions, AFLP analysis, and cpDNA haplotypes of natural populations clearly demonstrated that U. australis f. australis originates from the asymmetric hybridization between two parental taxa: U. australis f. tenuicaulis (mostly as female) and U. macrorhiza (mostly as male). No post-F, hybrids were detected using the additive patterns of AFLP bands combined with the observation of extensive sterility in U. australis f. australis. Recurrent hybridizations and subsequent perpetuation by asexual reproduction were demonstrated by the unique, but monomorphic, AFLP genotypes observed in each U. australis f. australis population. Hybrids and parental species did not coexist, implying the superiority of the hybrid U. australis f. australis in certain environmental conditions. It remains unclear whether populations of U. australis f. australis are maintained by colonizing propagules or as relicts of past hybridization events.