Li He, Zhou Guo-Ying, Liu Jun-Ang, Xu Jianping
The Ministry of Education Key Laboratory for Non-Wood Forest Cultivation and Conservation, Central South University of Forestry and Technology, Changsha, China.
College of Forestry, Central South University of Forestry and Technology, Changsha, China.
PLoS One. 2016 Jun 14;11(6):e0156841. doi: 10.1371/journal.pone.0156841. eCollection 2016.
The filamentous fungus Colletotrichum fructicola is found in all five continents and is capable of causing severe diseases in a number of economically important plants such as avocado, fig, cocoa, pear, and tea-oil trees. However, almost nothing is known about its patterns of genetic variation and epidemiology on any of its host plant species. Here we analyzed 167 isolates of C. fructicola obtained from the leaves of tea-oil tree Camellia oleifera at 15 plantations in seven Chinese provinces. Multilocus sequence typing was conducted for all isolates based on DNA sequences at fragments of four genes: the internal transcribed spacers of the nuclear ribosomal RNA gene cluster (539 bp), calmodulin (633 bp), glutamine synthetase (711 bp), and glyceraldehyde-3-phosphate dehydrogenase (190 bp), yielding 3.52%, 0.63%, 8.44%, and 7.89% of single nucleotide polymorphic sites and resulting in 15, 5, 12 and 11 alleles respectively at the four gene fragments in the total sample. The combined allelic information from all four loci identified 53 multilocus genotypes with the most frequent represented by 21 isolates distributed in eight tea-oil plantations in three provinces, consistent with long-distance clonal dispersal. However, despite evidence for clonal dispersal, statistically significant genetic differentiation among geographic populations was detected. In addition, while no evidence of recombination was found within any of the four gene fragments, signatures of recombination were found among the four gene fragments in most geographic populations, consistent with sexual mating of this species in nature. Our study provides the first insights into the population genetics and epidemiology of the important plant fungal pathogen C. fructicola.
丝状真菌果生炭疽菌在五大洲均有发现,能够在许多具有重要经济价值的植物上引发严重病害,如鳄梨、无花果、可可、梨和油茶树。然而,对于其在任何寄主植物物种上的遗传变异模式和流行病学情况,人们几乎一无所知。在此,我们分析了从中国七个省份的15个种植园的油茶树(Camellia oleifera)叶片上分离得到的167株果生炭疽菌。基于四个基因片段的DNA序列对所有分离株进行多位点序列分型:核糖体RNA基因簇的内部转录间隔区(539 bp)、钙调蛋白(633 bp)、谷氨酰胺合成酶(711 bp)和甘油醛-3-磷酸脱氢酶(190 bp),在总样本中这四个基因片段的单核苷酸多态性位点分别为3.52%、0.63%、8.44%和7.89%,并且分别产生了15、5、12和11个等位基因。来自所有四个位点的组合等位基因信息鉴定出53种多位点基因型,其中最常见的由21个分离株代表,分布在三个省份的八个油茶树种植园中,这与远距离克隆传播一致。然而,尽管有克隆传播的证据,但仍检测到地理种群之间存在统计学上显著的遗传分化。此外,虽然在四个基因片段中的任何一个内均未发现重组证据,但在大多数地理种群的四个基因片段之间发现了重组特征,这与该物种在自然中的有性交配一致。我们的研究首次揭示了重要植物真菌病原菌果生炭疽菌的群体遗传学和流行病学情况。