Self-Incompatibility in Apricot: Identifying Pollination Requirements to Optimize Fruit Production

Area of Science:

• Horticulture
• Plant Breeding
• Molecular Genetics

Background:

• Apricot cultivar renewal involves new releases, often incorporating self-incompatibility traits from parents resistant to sharka disease (plum pox virus).
• The increasing prevalence of self-incompatible apricot cultivars necessitates understanding their pollination requirements for effective orchard management and breeding.

Purpose of the Study:

• To determine the pollination requirements of new apricot cultivars by identifying their S-alleles.
• To compile comprehensive information on the pollination needs of a wide range of apricot cultivars.

Main Methods:

• Molecular identification of S-alleles using PCR amplification of RNase and SFB regions with specific primer combinations.
• Genotyping of 66 apricot cultivars to determine their S-genotype.

Main Results:

• The S-genotype of 66 apricot cultivars was determined, with 41 reported for the first time.
• Forty-nine cultivars were identified as self-compatible and 12 as self-incompatible, assigned to their respective incompatibility groups.
• A comprehensive compilation of pollination requirements for 235 apricot cultivars was created by integrating new findings with existing data.

Conclusions:

• The determined S-genotypes provide essential data for efficient parent selection in apricot breeding programs.
• Understanding cultivar pollination requirements aids in the proper design of new orchards and troubleshooting fruit set issues in existing ones.
• Observed diversity at the S-locus suggests a potential genetic bottleneck in breeding programs due to limited parent usage.