Interspecific hybridization and apomixis between Phytophthora capsici and Phytophthora tropicalis
Interspecific hybridization and apomixis between Phytophthora capsici and Phytophthora tropicalis
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DOI：
10.3852/08-028
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发表时间：
2008-11-01
期刊：
影响因子：
2.8
通讯作者：
Lamour, Kurt H.
中科院分区：
文献类型：
--
作者：
Donahoo, Ryan S.;Lamour, Kurt H.
辣椒疫霉（Phytophthora capsici）和近缘的热带疫霉（Phytophthora tropicalis）感染不同的宿主，其地理分布重叠。辣椒疫霉攻击一年生蔬菜宿主，而PO。已从木本多年生宿主中回收了热带假单胞菌。本研究以南瓜中的辣椒疫霉（LT 263）与杜鹃花中的热带疫霉（LT 232）和可可中的热带疫霉（LT 12）进行杂交，研究了辣椒疫霉与杜鹃花中的热带疫霉（LT 232）和可可中的热带疫霉（LT 12）的种间杂交。分析了野生型菌株的线粒体和核DNA序列多样性，并对后代进行了交配型（MT）、AFLP标记谱和线粒体DNA单倍型（mtDNA型）检测。来自LT 263 X LT 12的所有oopsore后代与LT 263相同，而来自LT 263 X LT 232的后代是亲本以及杂种。杂种后代可能有一个或另一个亲本mtDNA类型，MT与mtDNA类型之间没有相关性。从杂种产生所有F-2群体的尝试被证明是不成功的，而与辣椒疫霉亲本的回交产生了杂种后代。这些结果表明，无融合生殖可能在物种分离中起重要作用，辣椒疫霉和热带疫霉之间的杂交可能超过F-1代。
Phytophthora capsici and the closely related Phytophthora tropicalis infect different hosts that have documented overlapoing geographical distributions. Phytophthora capsici attacks annual vegetable hosts whereas PO. tropicalis has been recovered from woody perennial hosts. Our objective was to test whether interspecific hybridization is possible and to characterize the resulting progeny.Crosses were made between P.capsici (LT263) from pumpkin to P. tropicalis from rhododendron (LT232) and to P. tropicalis from Theobroma cacao (LT12). The wild type isolates were analyzed for mitochondrial and nuclear DNA sequence diveristy and progeny were tested for mating type (MT), AFLP marker profiles and mitochondrial DNA haplotype (mtDNA type). All oopsore progeny from LT263 x LT12 were identical to LT263 whereas progeny from LT263 X LT232 were parental as well as hybrid. Hybrid progeny had either one or the other parent mtDNA type and there was no correlation between MT and mtDNA type. Attempts to generate all F-2 population from the hybrids proved unsuccessful while a backcross to the P. capsici parent produced hybrid progeny. These results demonstrate that apomixis might play a significant role in species separation and that hybridization between P. capsici and P. tropicalis is possible beyond the F-1 generation.