Sommerhalder Rubik J, McDonald Bruce A, Mascher Fabio, Zhan Jiasui
Plant Pathology, Institute of Integrative Biology, ETH Zurich, LFW, Universitaetstrasse, Zürich, Switzerland.
Phytopathology. 2010 Sep;100(9):855-62. doi: 10.1094/PHYTO-100-9-0855.
We conducted a 2-year mark-release-recapture field experiment to quantify the relative contributions of immigration and sexual and asexual reproduction to epidemics of Stagonospora nodorum blotch caused by Phaeosphaeria nodorum. The epidemic was initiated using nine genetically distinct P. nodorum isolates. Infected plants were sampled four times across two growing seasons. In total, 1,286 isolates were recovered and assayed with 10 microsatellite markers and 1 minisatellite marker. The proportion of isolates having multilocus haplotypes (MLHTs) identical to the inoculated isolates decreased steadily from 86% in the first collection to 25% in the fourth collection. The novel isolates that had different MLHTs compared with the marked inoculants originated through immigration and sexual recombination. By the end of the experiment, nearly three-quarters of the novel isolates originated from sexual recombination. Our results indicate that recombinant offspring and airborne immigrant ascospores can make significant contributions to epidemics of Stagonospora nodorum blotch during a growing season.
我们进行了一项为期两年的标记重捕田间试验，以量化迁移以及有性和无性繁殖对由小麦小球腔菌引起的小麦壳针孢叶枯病流行的相对贡献。使用九个遗传上不同的小麦小球腔菌分离株引发病害流行。在两个生长季节中对受感染的植株进行了四次采样。总共回收了1286个分离株，并用10个微卫星标记和1个小卫星标记进行了分析。具有与接种分离株相同的多位点单倍型（MLHTs）的分离株比例从第一次采集时的86%稳步下降到第四次采集时的25%。与标记接种物相比具有不同MLHTs的新分离株源自迁移和有性重组。到试验结束时，近四分之三的新分离株源自于有性重组。我们的结果表明，重组后代和空气中传播的迁移子囊孢子在生长季节对小麦壳针孢叶枯病的流行有显著贡献。
