The five primary mechanisms of genomic instability in all flowering plants are polyploidy, transposon amplification, chromosome breakage, unequal homologous recombination and illegitimate recombination.
在開花植物中，基因組不穩(wěn)定性的五個主要機(jī)制是：多倍化论咏，轉(zhuǎn)座子擴(kuò)張优炬，染色體斷裂，不平衡同源重組和異常重組厅贪。
來源：Patterns in grass genome evolution - ScienceDirect?（應(yīng)該來源自這篇文章蠢护，我下不到這篇文章的原文了，因?yàn)槭召M(fèi)）
一养涮，polyploidy:多倍化
來源：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.
多倍化是由于在有絲分裂或減數(shù)分裂過程中染色體的完全不分離葵硕。
Polyploidy is common among plants and has been, in fact, a major source of?speciation?in the?angiosperms. Particularly important is?allopolyploidy 【異源多倍化】, 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種分化來源贯吓，尤其是異源多倍化懈凹。正常情況下雜交物種是不育的，因?yàn)闇p數(shù)分裂染色體無法同源配對產(chǎn)生配子體宣决。而通過多倍化產(chǎn)生的異源多倍體是可以進(jìn)行減數(shù)分裂的蘸劈，因?yàn)閬碓从谕荒副镜娜旧w可以進(jìn)行配對。多倍化賦予了雜交物種繁殖能力尊沸。據(jù)估計威沫，一半以上已知的被子植物來源于多倍化。
二洼专，transposon amplification
