Self compatibility in garden Chrysanthemum: occurrence, inheritance and breeding potential

Area of Science:

• Plant breeding
• Genetics
• Horticulture

Background:

• Self compatibility (SC) is uncommon in the typically self-incompatible (SI) hexaploid garden chrysanthemum (Chrysanthemum morifolium).
• Understanding the genetic basis of SC is crucial for breeding programs aiming to improve compatibility and seed production.

Purpose of the Study:

• To investigate the inheritance patterns of self compatibility (SC) in Chrysanthemum morifolium.
• To assess the potential of SC for producing inbred lines and improving breeding efficiency.

Main Methods:

• Conducted a series of self and cross-pollinations using three distinct SC sources in Chrysanthemum morifolium.
• Analyzed F1 progenies from crosses between SC and SI plants, including reciprocal crosses.
• Evaluated seed yield and compatibility classes (SC and SI) in different progenies.

Main Results:

• SC was consistently transmitted in F1 progenies from SC x SI crosses, with no observed maternal effects.
• Inheritance of SC appeared complex, potentially involving multiple genes or modifications by other genes (e.g., S-genes), rather than a single dominant factor.
• Some progenies showed clear SC/SI separation, while others exhibited pseudoself-compatibility, indicating complex genetic interactions.
• SC facilitated the production of large quantities of inbred seed for I1 and I2 generations.

Conclusions:

• Self compatibility in Chrysanthemum morifolium is a heritable trait with a complex genetic basis.
• SC offers a valuable tool for chrysanthemum breeding, enabling efficient production of inbred lines and enhancing combined self and cross-compatibility.