The modern cultivars of sugarcane (Saccharum spp.) are highly polyploid and accumulate aneuploidies due to their history of domestication, genetic improvement and interspecific hybrid origin involving the domesticated sweet species Saccharum officinarum (‘noble cane’) and the wild Saccharum spontaneum, both with an evolutionary history of polyploidy. The first hybrids were backcrossed with S. officinarum, and selection from progenies in subsequent generations established the genetic basis of modern cultivars. Saccharum genome complexity has inspired several molecular studies that have elucidated aspects of sugarcane genome constitution, architecture and cytogenetics. Herein, we conducted a comparative analysis of the meiotic behaviour of representatives of the parentals S. officinarum and S. spontaneum, and the commercial variety, SP80-3280. S. officinarum, an octoploid species, exhibited regular meiotic behaviour. In contrast, S. spontaneum and SP80-3280 exhibited several abnormalities from metaphase I to the end of division. We reported and typified, for the first time, the occurrence of peri- and paracentric inversions. Using in-situ hybridisation techniques, we were able to determine how pairing association occurred at diakinesis, the origin of lagging chromosomes and, in particular, the mitotic chromosome composition of SP80-3280. Interestingly, S. spontaneum and recombinant chromosomes showed the most marked tendency to produce laggards in both divisions. Future attempts to advance knowledge on sugarcane genetics and genomics should take meiotic chromosome behaviour information into account.

中文翻译：

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甘蔗（Saccharum spp.）和亲本物种的减数分裂异常：围绕中心和中心倒位的证据

现代甘蔗品种（Saccharum spp.）是高度多倍体，并且由于其驯化历史、遗传改良和种间杂交起源而积累非整倍体，其中包括驯化的甜品种Saccharum officinarum（“贵族甘蔗”）和野生Saccharum spontaneum，两者都具有多倍体的进化史。第一个杂交品种与铁皮植物回交，并从后代后代中进行选择，建立了现代品种的遗传基础。甘蔗基因组的复杂性激发了多项分子研究，这些研究阐明了甘蔗基因组的组成、结构和细胞遗传学的各个方面。在此，我们对亲本S. officinarum和S. spontaneum以及商业品种 SP80-3280 的减数分裂行为进行了比较分析。S. officinarum是一种八倍体物种，表现出规则的减数分裂行为。相比之下，S. spontaneum和 SP80-3280 从中期 I 到分裂末期表现出一些异常。我们首次报告并典型地描述了绕中心倒转和旁中心倒转的发生。使用原位杂交技术，我们能够确定在终变过程中配对关联是如何发生的、滞后染色体的起源，特别是 SP80-3280 的有丝分裂染色体组成。有趣的是，S. spontaneum和重组染色体在两个部门中都表现出最明显的产生落后者的趋势。未来推进甘蔗遗传学和基因组学知识的尝试应考虑减数分裂染色体行为信息。