Interploidal hybridization and mating patterns in the Sphagnum subsecundum complex
Interploidal hybridization and mating patterns in the Sphagnum subsecundum complex
复制标题
泥炭藓亚继孔复合体中的倍体杂交和交配模式
作者：
M. Ricca;M. Ricca;P. Szövényi;E. Temsch;Matthew G. Johnson;A. Shaw
多倍体化被认为是导致即时同域物种形成，但几个例子之间的杂交区的一个亲本物种和它的多倍体衍生物已被证明。以往的研究表明，二倍体泥炭藓是由单倍体S. lescurii（母系祖先）和S. subsecretary（父系祖先）。在这里，我们报告的结果，从一个群体的分析，其中异源二倍体和单倍体S。lescurii共生并产生孢子体。我们测试了（i）单倍体和二倍体是否形成杂种三倍体孢子体;（ii）杂种和非杂种孢子体在适合度上的比较;（iii）杂种孢子体是否形成有活力的孢子;（iv）杂种孢子体的任何有活力的配子体后代的倍性;（v）杂种和非杂种孢子体产生的孢子的相对活力;和（vi）倍体间杂交是否导致异源多倍体和其单倍体祖先之间的基因渗入。我们发现，三倍体杂交孢子体确实发生，比非杂交孢子体大，但表现出非常低的发芽率和产生孢子，比那些从非杂交孢子体发展缓慢。所有附着在单倍体配子体上的孢子体都是三倍体，并由二倍体雄性产生，但所有附着在二倍体配子体上的孢子体都是四倍体。这种不对称的倍体间杂交模式与种群中没有单倍体雄配子体有关。令人惊讶的是，所有从三倍体孢子体中产生的孢子都是三倍体，但遗传变异，这表明某种形式的异常减数分裂值得进一步研究。异源二倍体和单倍体S. lescurii。
Polyploidization is thought to result in instant sympatric speciation, but several cases of hybrid zones between one of the parental species and its polyploid derivative have been documented. Previous work showed that diploid Sphagnum lescurii is an allopolyploid derived from the haploids S. lescurii (maternal progenitor) and S. subsecundum (paternal progenitor). Here, we report the results from analyses of a population where allodiploid and haploid S. lescurii co‐occur and produce sporophytes. We tested (i) whether haploids and diploids form hybrid triploid sporophytes; (ii) how hybrid and nonhybrid sporophytes compare in fitness; (iii) whether hybrid sporophytes form viable spores; (iv) the ploidy of any viable gametophyte offspring from hybrid sporophytes; (v) the relative viability of sporelings derived from hybrid and nonhybrid sporophytes; and (vi) if interploidal hybridization results in introgression between the allopolyploid and its haploid progenitor. We found that triploid hybrid sporophytes do occur and are larger than nonhybrid sporophytes, but exhibit very low germination percentages and produce sporelings that develop more slowly than those from nonhybrid sporophytes. All sporophytes attached to haploid gametophytes were triploid and were sired by diploid males, but all sporophytes attached to diploid gametophytes were tetraploid. This asymmetric pattern of interploidal hybridization is related to an absence of haploid male gametophytes in the population. Surprisingly, all sporelings from triploid sporophytes were triploid, yet were genetically variable, suggesting some form of aberrant meiosis that warrants further study. There was limited (but some) evidence of introgression between allodiploid and haploid S. lescurii.
影响因子：
3
作者：
Linder, CR;Rieseberg, LH
通讯作者：
Rieseberg, LH
使用多位点基因型数据推断群体结构：连锁位点和相关等位基因频率。
影响因子：
3.3
作者：
Falush,Daniel;Stephens,Matthew;Pritchard,JonathanK
通讯作者：
Pritchard,JonathanK