PHYSICAL AND GENETIC MAPPING OF MAIZE CHROMOSOME 9S USING MUTATIONS WITH TERMINAL DEFICIENCIES

摘要

Undoubtedly, cytogenetic materials containing chromosomal alterations, such as translocations, and inversions derived from X ray irradiation or other means have made a tremendous contribution to our understanding of chromosome behaviour in plants. In maize, such materials have been applied to gene mapping, and linkage group assignment dating back to the 1930s [1, 2]. During meiosis, plants heterozygous to parametric inversion will give rise to a dicentric bridge following a crossover within the inverted segment. Random breakage at this bridge configuration can further lead to the formation of altered chromosomes with deficiencies or duplications.