The five primary mechanisms of genomic instability in all flowering plants are polyploidy, transposon amplification, chromosome breakage, unequal homologous recombination and illegitimate recombination.
在开花植物中，基因组不稳定性的五个主要机制是：多倍化，转座子扩张，染色体断裂，不平衡同源重组和异常重组。
来源：Patterns in grass genome evolution - ScienceDirect （应该来源自这篇文章，我下不到这篇文章的原文了，因为收费）
一，polyploidy:多倍化
来源：polyploidy | Definition, Examples, Types, & Facts | Britannica
polyploidy, the condition in which a normally diploid cell or organism acquires one or more additional sets of chromosomes. In other words, the polyploid cell or organism has three or more times the haploid chromosome number. Polyploidy arises as the result of total nondisjunction of chromosomes during mitosis or meiosis.
多倍化是由于在有丝分裂或减数分裂过程中染色体的完全不分离。
Polyploidy is common among plants and has been, in fact, a major source of speciation in the angiosperms. Particularly important is allopolyploidy 【异源多倍化】, which involves the doubling of chromosomes in a hybrid plant. Normally a hybrid is sterile because it does not have the required homologous pairs of chromosomes for successful gamete formation during meiosis. If through polyploidy, however, the plant duplicates the chromosome set inherited from each parent, meiosis can occur, because each chromosome will have a homologue derived from its duplicate set. Thus, polyploidy confers fertility on the formerly sterile hybrid, which thereby attains the status of a full species distinct from either of its parents. It has been estimated that up to half of the known angiosperm species arose through polyploidy, including some of the species most prized by man. Plant breeders utilize this process, treating desirable hybrids with chemicals, such as colchicine, that are known to induce polyploidy.
多倍化在植物中普遍存在，是被子植物主要的物种分化来源，尤其是异源多倍化。正常情况下杂交物种是不育的，因为减数分裂染色体无法同源配对产生配子体。而通过多倍化产生的异源多倍体是可以进行减数分裂的，因为来源于同一母本的染色体可以进行配对。多倍化赋予了杂交物种繁殖能力。据估计，一半以上已知的被子植物来源于多倍化。
二，transposon amplification
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