Based on the genomics model of plant chromosome evolution and bioinformatics methods and software mainly previously proposed by the author and colleagues, we are conducting in-depth analysis of the sequenced plant genome sequence, and plan to reconstruct the main ancestor nodes in the process of plant evolution. The so-called telomere-central model described chromosome arrangements, which occur in mainly three ways, nested-chromosome fusion, end-end joining of chromosomes, and arm exchange between chromosomes. Chromosome number reduction is indispensably accompanied by the production of B chromosomes, consisting two telomeres from one or two chromosomes. For nested chromosome fusion, one ancestral chromosome initially forms a circular one by crossing-over near its two telomeres, and a resolution of the Holiday structure results in a telomere-free or free-end chromosome and a B chromosome; then the free-end chromosome is nested into another chromosome, and the B chromosome will be lost. For the end-end joining of chromosomes, two ancestral chromosomes cross-over near one of each one’s telomere, and the resolution results in the production of a fused bigger chromosome and a B-chromosome, the latter of which will be lost. In our study, the ancestral karyotype and chromosome evolutionary trajectories are inferred and displayed in static and dynamic manners, involving many angiosperm plants.
 

Genome;Cell karyotype;Chromosome;Evolution