CYTOGENETIC CHARACTERIZATION OF MEIOTIC CHROMOSOME DYNAMICS IN HYBRID PLANT SPECIES

Abstract

Background: Hybridization is an important factor in plant evolution, genetic variation and crop improvement. However, meiotic chromosome instability in hybrid species often leads to aberrant chromosome segregation, reduced fertility and compromised genome stability.

Objective: The objective of this study was to study meiotic chromosome dynamics and cytogenetic abnormalities in hybrid plant species by using classical and molecular cytogenetic approaches.

Methodology: Cytogenetic analyses were done with fluorescence microscopy, chromosome staining, fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH). The chromosome pairing behavior, meiotic abnormalities, formation of micronuclei and genome recombination during meiotic stages were screened in hybrid plant meiocytes.

Findings: Experimental analysis revealed 42% frequency of univalent chromosome formation, 31% lagging chromosomes and 28% chromosomal bridges in meiosis. A 36% increase in micronuclei formation was observed in hybrid cells relative to parental controls. Aberrant chromosomal segregation and genomic incompatibility led to reduced pollen fertility (58%) and seed viability (62%) in hybrid plants.

Conclusion: Cytogenetic characterization clearly demonstrated meiotic chromosome instability and genome interactions in hybrid plant species. The results provide important insights into chromosome dynamics, hybrid fertility and genome stability for the improvement of plant breeding and agricultural biotechnology applications.