Genomic affinities between maize and Zea perennis using classical and molecular cytogenetic methods (GISH-FISH)

Area of Science:

• Plant genetics
• Cytogenetics
• Genomics

Background:

• Understanding the genomic composition and meiotic behavior of plant species is crucial for evolutionary studies.
• Zea perennis and Zea mays ssp. mays (maize) are closely related species within the Zea genus, necessitating comparative genomic analysis.

Purpose of the Study:

• To analyze and compare the genomic composition, meiotic behavior, and meiotic affinities of Zea perennis and Zea mays ssp. mays.
• To investigate the parental taxa and their interspecific hybrid (Zea perennis x Zea mays ssp. mays) using advanced cytogenetic techniques.

Main Methods:

• Employed classical cytogenetic methods.
• Utilized fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) techniques.
• GISH was specifically used to identify the genomic origin of chromosomes in the hybrid's meiotic configurations.

Main Results:

• GISH analysis successfully identified the genomic source of each chromosome in the Zea perennis x Zea mays ssp. mays hybrid.
• Established clear genomic affinities between the parental species, Zea perennis and Zea mays ssp. mays.
• Results reinforce the hypothesis of an amphiploid origin for Zea perennis.

Conclusions:

• The study provides strong evidence supporting the amphiploid origin of Zea perennis.
• Findings suggest that divergent repetitive sequences in maize and Zea luxurians may represent a relict parental genome not shared with Zea perennis.