Nibouche Samuel, Fartek Benjamin, Mississipi Stelly, Delatte Hélène, Reynaud Bernard, Costet Laurent
Cirad, UMR PVBMT, Saint-Pierre, La Réunion, France.
Cirad, UMR PVBMT, Saint-Pierre, La Réunion, France; Université de la Réunion, UMR PVBMT, Saint-Pierre, La Réunion, France.
PLoS One. 2014 Aug 22;9(8):e106067. doi: 10.1371/journal.pone.0106067. eCollection 2014.
Numerous studies have examined the genetic diversity and genetic structure of invading species, with contrasting results concerning the relative roles of genetic diversity and phenotypic plasticity in the success of introduced populations. Increasing evidence shows that asexual lineages of aphids are able to occupy a wide geographical and ecological range of habitats despite low genetic diversity. The anholocyclic aphid Melanaphis sacchari is a pest of sugarcane and sorghum which originated in the old world, was introduced into the Americas, and is now distributed worldwide. Our purpose was to assess the genetic diversity and structuring of populations of this species according to host and locality. We used 10 microsatellite markers to genotype 1333 individuals (57 samples, 42 localities, 15 countries) collected mainly on sugarcane or sorghum. Five multilocus lineages (MLL) were defined, grouping multilocus genotypes (MLG) differing by only a few mutations or scoring errors. Analysis of a 658 bp sequence of mitochondrial COI gene on 96 individuals revealed five haplotypes, with a mean divergence of only 0.19 %. The distribution of MLL appeared to be strongly influenced by geography but not by host plant. Each of the five MLL grouped individuals from (A) Africa, (B) Australia, (C) South America, the Caribbean and the Indian Ocean including East Africa, (D) USA, and (E) China. The MLL A and C, with a wide geographic distribution, matched the definition of superclone. Among aphids, M. sacchari has one of the lowest known rates of genetic diversity for such a wide geographical distribution.
众多研究考察了入侵物种的遗传多样性和遗传结构,关于遗传多样性和表型可塑性在引入种群成功中的相对作用,结果存在差异。越来越多的证据表明,尽管遗传多样性较低,但蚜虫的无性系谱系能够占据广泛的地理和生态栖息地范围。无全周期型蚜虫甘蔗缢管蚜是甘蔗和高粱的一种害虫,原产于旧世界,被引入美洲,现分布于全球。我们的目的是根据寄主和地点评估该物种种群的遗传多样性和结构。我们使用10个微卫星标记对主要在甘蔗或高粱上采集的1333个个体(57个样本,42个地点,15个国家)进行基因分型。定义了五个多位点谱系(MLL),将仅因少数突变或评分误差而不同的多位点基因型(MLG)分组。对96个个体的线粒体COI基因658 bp序列的分析揭示了五个单倍型,平均差异仅为0.19%。MLL的分布似乎受地理因素强烈影响,但不受寄主植物影响。五个MLL中的每一个都将来自(A)非洲、(B)澳大利亚、(C)南美洲、加勒比地区和包括东非在内的印度洋、(D)美国以及(E)中国的个体分组。地理分布广泛的MLL A和C符合超级克隆的定义。在蚜虫中,甘蔗缢管蚜在如此广泛的地理分布中具有已知的最低遗传多样性比率之一。