Intra- and inter-specific reproductive barriers in the tomato clade

Area of Science:

• Plant genetics
• Crop science
• Reproductive biology

Background:

• Tomato (Solanum lycopersicum L.) domestication led to reduced genetic variation.
• Wild tomato species (Lycopersicon clade) offer genetic diversity for improved agronomic traits, including stress tolerance.
• Intraspecific and interspecific incompatibility barriers hinder crosses between tomato and its wild relatives.

Purpose of the Study:

• To review known incompatibility barriers within the Lycopersicon clade.
• To provide an overview of general and specific self-incompatibility mechanisms.
• To detail unilateral incompatibility in Lycopersicon and its implications for breeding.

Main Methods:

• Literature review of self-incompatibility and unilateral incompatibility mechanisms.
• Analysis of incompatibility in the Lycopersicon clade, including loss of self-incompatibility.
• Examination of unilateral incompatibility pathways and their relationship with self-incompatibility.

Main Results:

• Incompatibility barriers, including gametophytic self-incompatibility and unilateral incompatibility, exist in the Lycopersicon clade.
• Species within the Lycopersicon clade exhibit varying degrees of self-compatibility and self-incompatibility.
• Specific rules and pathways of unilateral incompatibility, influenced by self-incompatibility, were detailed.

Conclusions:

• Understanding incompatibility barriers is crucial for leveraging genetic diversity from wild relatives for tomato improvement.
• Addressing these barriers can facilitate crosses for enhanced tomato breeding programs.
• Advances in understanding compatibility offer new strategies for developing resilient tomato varieties.