The impact of genomic structural variation on meiotic pairing and segregation in Beta vulgaris subsp. maritima

Abstract

• A method of ND FISH was employed to identify structural variation in Beta vulgaris subsp. maritima and to evaluate the impact of this variation on meiotic behaviours, specifically synapsis and segregation of chromosomes. An intercalary region (pEV1) on the chromosome IV arm exhibited asymmetry in signals, allowing individual homologues to be distinguished; indicative of asynapsis in this region. Condensation appears to be non-uniform along the chromosome IV arm, with reduced condensation within the pEV1 intercalary region relative to other regions on the chromosome. The potential asynapsis, alongside reduced condensation, is suggestive of structural variation in this region. Specimens showcased a large number of bridges at anaphase I and low pollen viability however, no correlation between the two suggests that the bridges observed are likely not the sole cause of low fertility in these plants, nor can they be directly linked with the potential structural variation identified.