Additional rDNA ITS sequences and its phylogenetic consequences for the genus Leveillula with emphasis on conidium morphology
Additional rDNA ITS sequences and its phylogenetic consequences for the genus Leveillula with emphasis on conidium morphology
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DOI：
10.1007/s11557-011-0785-7
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发表时间：
2012-08
影响因子：
2.4
通讯作者：
S. A. Khodaparast;S. Takamatsu;M. Harada;M. Abbasi;S. Samadi
中科院分区：
文献类型：
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作者：
S. A. Khodaparast;S. Takamatsu;M. Harada;M. Abbasi;S. Samadi
白粉病属的分类一直是白粉病系统学研究中的一个难题。rDNA多样性最近已被用于几个标本的Leveillula的系统发育分析。在本研究中，额外的rDNA ITS序列，并进行了一个新的系统发育分析，旨在更好地了解该属的遗传多样性。新的分析证实L.金牛座是独特的属，因为它表现出种内基因序列多样性大大高于其他物种。在一些情况下，陶里卡湾在某些寄主植物上具有与mL不同序列。tauricaon其他寄主植物。此外，DNA数据表明不同的血统。tauricaspecimens的形态几乎无法区分。在一个宿主上出现一个以上的基因型有时是可能的。根据这些结果，几个小种如蒿属的LeveillulaonArtemisia、尖叶蒿属的Acroptilon、红豆草属的Onobrychis在分子水平上得到了很好的鉴定。虽然有足够的分子证据划定这些种族作为独立的类群，明确的形态之间的界限，这些新的和已经公布的类群是非常困难的，甚至是不可能的。然而，生态学特征，尤其是对活体营养真菌如白粉病的宿主特异性，将是一个很好的标准，沿着rDNA序列来区分隐蔽分类群。事实上，许多收集的不同寄主上的Leveillula菌株显示出它们自己的分生孢子形态类型，这通常对于单一寄主物种上的菌株是一致的。因此，我们建议描述寄生在蒿属、尖叶蒿属、海胆属和红豆草属等植物上的新种。
Taxonomy of the genusLeveillulahas long been considered as a challenge in powdery mildew systematics. The rDNA diversity has recently been used for phylogenetic analysis of several specimens of the genusLeveillula. In the present study, additional rDNA ITS sequences are provided and a new phylogenetic analysis is carried out aiming at a better understanding of the genetic diversity in the genusLeveillula. New analyses confirmed thatL. tauricais unique in the genus, as it exhibits an intraspecific gene sequence diversity considerably higher than in other species. In several casesL. taurica s. lat.on a certain host plant species has a sequence different fromL. tauricaon other host plants. Moreover, DNA data indicated different lineages amongL. tauricaspecimens which were hardly distinguishable by morphology. More than one genotype occurring on a single host is sometimes possible. According to these results, several races such asLeveillulaonArtemisia,Acroptilon,Onobrychis, are molecularly well characterized. While there is enough molecular evidence to delimit such races as independent taxa, clear morphological delimitations between these new and already published taxa are very difficult or even impossible. However, ecological features, and above all, host specificity for biotrophic fungi such as powdery mildew, would be a good criterion to discriminate cryptic taxa along with rDNA sequences. In fact, many collections ofLeveillulastrains on different hosts show their own type of conidial morphology, which is usually consistent for a strain on a single host species. Hence, we have proposed to describe new species forLeveillulaon some host plants such asArtemisia,Acroptilon,EchinopsandOnobrychis.