Stochastic changes affect Solanum wild species following autopolyploidization.

Area of Science:

• Plant genetics and genomics
• Epigenetics and molecular biology
• Plant anatomy and physiology

Background:

• Polyploidy is common in angiosperms, but autopolyploidization effects are less understood than allopolyploidization.
• Solanum commersonii and Solanum bulbocastanum are diploid potato species crucial for breeding programs.
• Understanding autopolyploidy's impact is vital for crop improvement.

Purpose of the Study:

• To investigate genetic, epigenetic, and anatomical changes following induced autopolyploidy in two diploid potato species.
• To assess the impact of oryzaline-induced polyploidization on Solanum commersonii and Solanum bulbocastanum.
• To determine if autopolyploidy confers systematic trait advantages.

Main Methods:

• Induced autopolyploidy using oryzaline treatment.
• Microsatellite analysis to detect genetic polymorphisms.
• DNA methylation analysis (CG and CHG sites).
• Morpho-anatomical studies of leaf main veins and stomata.

Main Results:

• Microsatellite analysis revealed no polymorphisms between synthetic tetraploids and diploid progenitors.
• Subtle alterations in DNA methylation (CG and CHG sites) were observed, but changes were stochastic and not consistent across all tetraploids.
• Morpho-anatomical analyses showed no clear superiority of tetraploids in leaf thickness, area, vessel characteristics, or stomatal traits compared to diploids.

Conclusions:

• Induced autopolyploidy in these potato species resulted in stochastic epigenetic changes without consistent genetic alterations.
• Autopolyploidization did not lead to systematic improvements in the studied leaf and stomatal traits.
• The results support the hypothesis that autopolyploidy does not inherently confer systematically advantageous traits in these Solanum species.