Heteromorphic incompatibility retained in self-compatible plants produced by a cross between common and wild...

Area of Science:

• Plant genetics
• Reproductive biology
• Agricultural science

Background:

• Common buckwheat (Fagopyrum esculentum) exhibits heteromorphic self-incompatibility, with distinct pin and thrum flower morphs.
• The S supergene is believed to control self-incompatibility, flower morphology, and pollen size in buckwheat.

Purpose of the Study:

• To create self-compatible buckwheat lines through interspecific hybridization.
• To investigate the genetic basis of self-compatibility and its relationship with flower morphology and pollen characteristics.

Main Methods:

• Interspecific crossing between Fagopyrum esculentum and Fagopyrum homotropicum.
• Embryo rescue technique to obtain hybrid lines.
• Phenotypic analysis of flower morphology and pollen size in parental and F1 generations.

Main Results:

• Successfully produced self-compatible buckwheat lines with long homostyle morphology and thrum-like pollen size.
• F1 plants from crosses involving self-compatible lines showed segregation of traits linked to the self-compatibility allele (S^h).
• Pollen-style compatibility tests revealed complex interactions, with S^h retaining heteromorphic incompatibility features.

Conclusions:

• The self-compatibility allele (S^h) in buckwheat retains elements of heteromorphic incompatibility.
• These findings suggest that the S^h allele likely arose from recombination within the S supergene.
• This study provides insights into the evolution of self-compatibility and the S supergene in Fagopyrum species.