Somatic hybrids between unilateral cross-incompatible Petunia species

Area of Science:

• Plant biotechnology
• Somatic hybridization
• Reproductive biology

Background:

• Petunia species exhibit pre-zygotic reproductive isolation, hindering sexual hybridization.
• Somatic hybridization offers an alternative method for interspecific plant breeding.
• Albino P. inflata provides a selectable marker for identifying hybrid cells.

Purpose of the Study:

• To regenerate somatic hybrid plants from interspecific protoplast fusion.
• To overcome unilateral cross-incompatibility between Petunia parodii and P. inflata.
• To demonstrate the utility of somatic hybridization for creating novel plant varieties.

Main Methods:

• Isolation and fusion of leaf mesophyll protoplasts from Petunia parodii and P. inflata.
• Selection of somatic hybrids based on chlorophyll synthesis complementation and callus growth.
• Regeneration of shoots and flowering plants from hybrid calluses.

Main Results:

• Green somatic hybrid calluses were identified against albino P. inflata background.
• Regenerated plants displayed hybrid floral morphology, chromosome number, and segregated parental traits.
• Somatic hybrid production frequency was comparable to sexually compatible species.

Conclusions:

• Somatic hybridization effectively bypasses pre-zygotic reproductive barriers in Petunia.
• Complementation to chlorophyll synthesis serves as a reliable selection method for somatic hybrids.
• This technique facilitates the development of novel interspecific Petunia hybrids.