Germination characteristics of native Japanese dandelion autopolyploids and their putative diploid parent species
Germination characteristics of native Japanese dandelion autopolyploids and their putative diploid parent species
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DOI：
10.1007/s10265-006-0034-3
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发表时间：
2007-01-01
影响因子：
2.8
通讯作者：
Ito, Motomi
中科院分区：
文献类型：
--
作者：
Hoya, Akihiko;Shibaike, Hiroyuki;Ito, Motomi
对日本蒲公英属植物广果蒲公英（二倍体）、T. venustum（三倍体和四倍体）和T. albidum（五倍体）在不同温度下进行了研究。宽果蒲公英hondoense是T. venustum。二倍体T.扁果类hondoense和多倍体T. venustum和T. albidum分布于日本不同地区，其分布差异可能反映了不同倍性水平的生态和生理特征。在这项研究中，为了防止不同多倍性的种子混合，我们使用流式细胞术来检查收集种子的植物的倍性水平。种子萌发实验结果表明，同源多倍体T。venustum和二倍体T.在高温和低温下，桔梗的萌发受到抑制。它还表明，同源多倍体的种子发芽抑制在低温下比祖先二倍体，多倍体的种子发芽率高于二倍体。在低温下的阈值变化可能会影响本地蒲公英的分布。生长在凉爽气候中的蒲公英在低温下可能会产生明显较低的发芽阈值，而T。原产于温暖气候的albidum可能在高温下形成了一个适应阈值。
Germination characteristics of native Japanese Taraxacum lineages of Taraxacum platycarpum (diploid), T. venustum (triploid and tetraploid), and T. albidum (pentaploid) have been studied at different temperatures. Taraxacum platycarpum ssp. hondoense is the putative diploid parent of T. venustum. Diploid T. platycarpum ssp. hondoense and the polyploids T. venustum and T. albidum are found in different areas of Japan, and distribution differences may reflect divergent ecological and physiological traits among ploidy levels. In this study, to prevent mixing of seeds of different polyploidy we used flow cytometry to examine the ploidy level of the plants from which seeds were collected. Results from seed-germination experiments showed that dependence on temperature of final percentage germination was qualitatively similar for both autopolyploids T. venustum and diploids T. platycarpum-germination was suppressed at high and low temperatures. It was also shown that seed germination of autopolyploids was suppressed more than that of the ancestral diploid at low temperatures and that seed germination for polyploids was higher than for the diploid. Threshold variations at low temperatures might affect the distribution of native dandelions. Taraxacum venustum, which occurs in cool climates, might have developed a distinctly lower germination threshold at low temperatures whereas T. albidum, which is native to warm climates, might have developed an adaptive threshold at high temperatures.